On 1 May, 11:11, whisky-dave wrote:
On Wednesday, May 1, 2013 12:33:51 AM UTC+1, wrote:
On Tuesday, April 30, 2013 11:35:49 PM UTC+1, The Other Mike wrote:

Equip the entire country of 24 million household with identical fridge freezers

and on average only 1/24 of them would be requiring power per one hour period.

They don't all turn on at precisely 17:32:06 and each present 4.8kW load to the

grid.

So for a typical A++ rated fridge freezer your entire demand control capability

for one hour is 600MW for an installed base of 24 million fridge freezers.

Install the same overall level of demand control for a few hundred commercial or

industrial consumers and the payback for the customer is much quicker, the costs

of implementing it are significantly lower for all parties, the customer sees

100% return on their invested capital in five years or so. The infrastructure to

support this demand control exists now and has done for a few decades.. *Above

all it requires no investment from anyone but the customer.

All smart metering schemes will require wiring changes/appliance

changes/infrastructure changes. *The benefit to the domestic end user is near

zero. *The benefit to grid system operator and distribution network operator is

near zero. *The only ones that benefit are the parasites supplying and

installing the appliances / equipment.

If the government keep their stupid fingers out, it won't be long before appliances with this feature are available for an extra £5.

No you'll be entered into a free prize draw....

*An 8 bit cpu can respond to frequency,

Not that easily,

Rubbish.

and I doubt using that method would be very successful.
Far better to have teh aplience switched off on demand from the suplier than wait for the frequency to alter which would be difficult to measure cheaply.

Be silly to have to measure the frequency of every device.

Be even silier to have to have power line comms hardware and asociated
software stack running on every device.

MBQ

On 1 May, 10:55, John Williamson
wrote:
On 01/05/2013 10:50, Man at B&Q wrote: On May 1, 8:18 am, harry wrote:

As any generator is in parallel with others, the speed/frequency,
* cannot change.

It does.

But not relative to the others.

That wasn't the issue.

MBQ

On 1 May, 11:32, The Natural Philosopher wrote:
On 01/05/13 10:47, Man at B&Q wrote: On May 1, 3:37 am, The Natural Philosopher
wrote:

A problem many have encountered in the RC electric plane world, where
controllers blow up at part throttle, not full (throttling being *done
by chopping the supply) .Its critically linked to the leakage inductance
of the motors: low inductance (the best motors) will have massive peak
currents at part throttle.
In the model train world it's expensive coreless motors that brick if
the PWM frequency is too low.

MBQ

ah well we went high frequency many moons ago. For that very reason.

Well, so did model trains, to be fair.

MBQ

"Man at B&Q" wrote:
On May 1, 3:37 am, The Natural Philosopher
wrote:


A problem many have encountered in the RC electric plane world, where
controllers blow up at part throttle, not full (throttling being done
by chopping the supply) .Its critically linked to the leakage inductance
of the motors: low inductance (the best motors) will have massive peak
currents at part throttle.

In the model train world it's expensive coreless motors that brick if
the PWM frequency is too low.

Well... Back in the day I saw an engineer brick £159,000 of avionics
because he connected it to a lab PSU and applied 50Hz instead of 400Hz. The
bang was very impressive.

--
€¢DarWin|
_/ _/

On Wednesday, May 1, 2013 11:11:28 AM UTC+1, whisky-dave wrote:
On Wednesday, May 1, 2013 12:33:51 AM UTC+1, wrote:
On Tuesday, April 30, 2013 11:35:49 PM UTC+1, The Other Mike wrote:

If the government keep their stupid fingers out, it won't be long before appliances with this feature are available for an extra £5.
No you'll be entered into a free prize draw....

An 8 bit cpu can respond to frequency,

Not that easily, and I doubt using that method would be very successful.

its not hard to divide the clock frequency down to 50Hz and time the period from local zero crossing to mains zero crossing, and log the latest value to see how far it moves.

Far better to have teh aplience switched off on demand from the suplier than wait for the frequency to alter which would be difficult to measure cheaply.

well, thats what checking the frequency achieves. How would you do it cheaper?

Be silly to have to measure the frequency of every device.

Either you measure locally or decide centrally and communicate. Do you think 2 way communication's cheaper?


and send the appliance serial number down the wiring now and then, and the power co software will automatically knock £1 off the bill.

Too much hassle and no need for it.

The user needs some reason to spend the cost of the control unit. If I were offered 20% ROI I'd buy, for a prize draw I wouldnt.


NT

The customer is free to choose, and it'll become popular because & when its worth it.
With government involvement it'll be nothing but problems and one more parasite ripping us off. Seems they really cant help but be idiots.

Andrew Gabriel wrote:

There's actually a large timing range for things like fridges (and
even more, freezers) that can cycle on/off without going outside
temperature spec. They do represent an excellent opportunity to store
energy. For example, if you know you're going to have a mass toilet
flushing and kettle boiling at the end of a royal wedding/funeral,
you could switch on freezers beforehand so they drop an extra 1C,
and then switch them off when the extra load is needed, and they then
won't use any more power for an extended period whilst you get the
toilet flushing and kettle boiling over and done with.
This is getting complicated. What about the thermostat?

Bill

On Wednesday, May 1, 2013 12:21:38 PM UTC+1, wrote:
On Wednesday, May 1, 2013 11:11:28 AM UTC+1, whisky-dave wrote:

On Wednesday, May 1, 2013 12:33:51 AM UTC+1, wrote:

On Tuesday, April 30, 2013 11:35:49 PM UTC+1, The Other Mike wrote:



If the government keep their stupid fingers out, it won't be long before appliances with this feature are available for an extra £5.

No you'll be entered into a free prize draw....



An 8 bit cpu can respond to frequency,



Not that easily, and I doubt using that method would be very successful..



its not hard to divide the clock frequency down to 50Hz ..
But you need a dedicated clock you can;t use the average MPUs clock as it's too inaccurate, you need a proper RTC, you do know that computers keep pretty crap time unless they get it from a server.
You wouldn;t use that method anyway as you need to mearuce the actual frequency of teh main not simulate it.


and time the period from local zero crossing to mains zero crossing, and log the latest value to see how far it moves.

Not necessary.




Far better to have teh aplience switched off on demand from the suplier than wait for the frequency to alter which would be difficult to measure cheaply.



well, thats what checking the frequency achieves. How would you do it cheaper?

Measure the frequency at the power station and if it's condered that power needs reducing lower the overall voltage supplied to the grid.
If yuo really need to switch things off then measure the frequency of the grid and if it's below what you see as a miniumium then send a single to turn off particular devices that are in yuor home that the smartmeter recognise.




Be silly to have to measure the frequency of every device.



Either you measure locally or decide centrally and communicate. Do you think 2 way communication's cheaper?

Yes.
Measuring low frequecies accuratly is more difficult than you think.
What you have to do is count cycles in one second yuod get perhaps 47 or 53 so you need to average it out especailly in times of high or low demand.
So you need to sample it for at least 10 seconds to giove you 0.1 resoultion and in that time the situation can change.

Anyway it would be cheaper to have just one device measuring frequency rather than every electrical device each reading it. If I were designing such a thing it'd use teh smart meter to measure it rather than install the ciruitry in my kettle and fridge.freeze, TV cooker shower , washing machine, coffee maker storage heaters fires hair dryer etc.....

What I'd get manufactiers of such devices to do it allocate a specific number to each product a bit like a MAC address which my smart meter can locate and be able to either just switch off/on or reduce it's power.

idf all 2KW+ kettles had a 1/2 power switch then my first try would be to turn those kettles is 1/2 power them, I wouldn't turn off motors or mmoving things such as food blenders.






and send the appliance serial number down the wiring now and then, and the power co software will automatically knock £1 off the bill.



Too much hassle and no need for it.



The user needs some reason to spend the cost of the control unit. If I were offered 20% ROI I'd buy, for a prize draw I wouldnt.

You don;t need to you make it cheap enough that no one would bother or you make it illegal to sell products without such things. We do this in the name of H&S, you can't normally buy appliences without leads, you have to buy them with the product or buy them seperatly.

I remmber the days when buying electrical equipment you HAD to purchse a lead or plug and put that on yuorself. Nowadays that's not possible for most people you can;t go and buy even a £5 kettle without a moulted lead.
You can't say IO'm not buying an electrical product that comes woth a free lead because i have plenty. I have about 150 IEC leads I'm not using in a box.

On Wednesday, May 1, 2013 1:54:36 PM UTC+1, whisky-dave wrote:
On Wednesday, May 1, 2013 12:21:38 PM UTC+1, wrote:
On Wednesday, May 1, 2013 11:11:28 AM UTC+1, whisky-dave wrote:
On Wednesday, May 1, 2013 12:33:51 AM UTC+1, wrote:
On Tuesday, April 30, 2013 11:35:49 PM UTC+1, The Other Mike wrote:

If the government keep their stupid fingers out, it won't be long before appliances with this feature are available for an extra £5.
No you'll be entered into a free prize draw....


An 8 bit cpu can respond to frequency,

Not that easily, and I doubt using that method would be very successful.

its not hard to divide the clock frequency down to 50Hz ..

But you need a dedicated clock you can;t use the average MPUs clock as it's too inaccurate, you need a proper RTC, you do know that computers keep pretty crap time unless they get it from a server.
You wouldn;t use that method anyway as you need to mearuce the actual frequency of teh main not simulate it.
and time the period from local zero crossing to mains zero crossing, and log the latest value to see how far it moves.
Not necessary.

All one need do is
a) xtal control the cpu clock, an xtal with no oven is more than accurate enough to read 50Hz +/- 0.1%.
b) count a divided version of the clock from one mains zero crossing to the next. Problem solved.

The slight frequency spread of the xtals prevents all appliances going off at the same time.


Far better to have teh aplience switched off on demand from the suplier than wait for the frequency to alter which would be difficult to measure cheaply.

well, thats what checking the frequency achieves. How would you do it cheaper?

Measure the frequency at the power station and if it's condered that power needs reducing lower the overall voltage supplied to the grid.

Voltage control would be quite unreliable, V swings about in normal healthy use for various reasons.


If yuo really need to switch things off then measure the frequency of the grid and if it's below what you see as a miniumium then send a single to turn off particular devices that are in yuor home that the smartmeter recognise.

So you're proposing that appliances have 2 way communications, and that smart meters talk to each appliance in each house. Doable of course, but its more money, so not attractive.


Be silly to have to measure the frequency of every device.

Either you measure locally or decide centrally and communicate. Do you think 2 way communication's cheaper?

Yes.

I'm struggling to see how enabling 2 way comms and playing with MACs is cheaper than a divider in the chip.

Measuring low frequecies accuratly is more difficult than you think.
What you have to do is count cycles in one second yuod get perhaps 47 or 53 so you need to average it out especailly in times of high or low demand.
So you need to sample it for at least 10 seconds to giove you 0.1 resoultion and in that time the situation can change.

Its not hard at all, just time the number of clock cycles between 2 successive crossings. You could average lots of counts but I don't believe there's a need to, a small percentage of mistimes is immaterial in practice. Simply averaging several yes or nos would be trivially easy.


Anyway it would be cheaper to have just one device measuring frequency rather than every electrical device each reading it. If I were designing such a thing it'd use teh smart meter to measure it rather than install the ciruitry in my kettle and fridge.freeze, TV cooker shower , washing machine, coffee maker storage heaters fires hair dryer etc.....

but you'd still need to install everything in the appliances, you'd only miss out the clock divider, which inside a custom single IC costs close to nothing.


What I'd get manufactiers of such devices to do it allocate a specific number to each product a bit like a MAC address which my smart meter can locate and be able to either just switch off/on or reduce it's power.

more costs

idf all 2KW+ kettles had a 1/2 power switch then my first try would be to turn those kettles is 1/2 power them, I wouldn't turn off motors or mmoving things such as food blenders.

I'd agree there. There are many things can be turned off or down if its ever worth it. Today its mostly not though.


and send the appliance serial number down the wiring now and then, and the power co software will automatically knock £1 off the bill.

Too much hassle and no need for it.

The user needs some reason to spend the cost of the control unit. If I were offered 20% ROI I'd buy, for a prize draw I wouldnt.

You don;t need to you make it cheap enough that no one would bother

that'll happen, but only after its already being widely bought, ie produced on a mass scale, with all the upfront investments paid off. To get to that point its going to cost, so there must be a customer upside.

or you make it illegal to sell products without such things.

but then its a protected parasite, & the cost stays high.


We do this in the name of H&S, you can't normally buy appliences without leads, you have to buy them with the product or buy them seperatly.
I remmber the days when buying electrical equipment you HAD to purchse a lead or plug and put that on yuorself. Nowadays that's not possible for most people you can;t go and buy even a £5 kettle without a moulted lead.
You can't say IO'm not buying an electrical product that comes woth a free lead because i have plenty. I have about 150 IEC leads I'm not using in a box.

Firstly this isnt a H&S issue, and there isnt anywhere near justification to force it on everyone. Second, phones are beginning to be sold now without chargers, and with IEC leads so common theyre moderately likely to become optional with cheap appliances. Government interference gets in the way of progress more than it helps it.


NT

On 1 May, 13:54, whisky-dave wrote:
On Wednesday, May 1, 2013 12:21:38 PM UTC+1, wrote:
On Wednesday, May 1, 2013 11:11:28 AM UTC+1, whisky-dave wrote:

On Wednesday, May 1, 2013 12:33:51 AM UTC+1, wrote:

On Tuesday, April 30, 2013 11:35:49 PM UTC+1, The Other Mike wrote:

If the government keep their stupid fingers out, it won't be long before appliances with this feature are available for an extra £5.

No you'll be entered into a free prize draw....

*An 8 bit cpu can respond to frequency,

Not that easily, and I doubt using that method would be very successful.

its not hard to divide the clock frequency down to 50Hz ..

But you need a dedicated clock you can;t use the average MPUs clock as it's too inaccurate,

It's as innacurate as the timebase used, whether it's an MPU or an
RTC. A crystal or ceramic resonator will do nicely.

you need a proper RTC,

There is nothing inherently accurate about RTCs.

you do know that computers keep pretty crap time unless they get it from a server.

Hint: What do you think keeps the time in your PC? That's right it's
an RTC which blows your argument out of the water.

You wouldn;t use that method anyway as you need to mearuce the actual frequency of teh main not simulate it.

Whose simulating it?

MBQ

On Wednesday, May 1, 2013 2:54:09 PM UTC+1, wrote:
On Wednesday, May 1, 2013 1:54:36 PM UTC+1, whisky-dave wrote:

On Wednesday, May 1, 2013 12:21:38 PM UTC+1, wrote:

On Wednesday, May 1, 2013 11:11:28 AM UTC+1, whisky-dave wrote:

On Wednesday, May 1, 2013 12:33:51 AM UTC+1, wrote:

On Tuesday, April 30, 2013 11:35:49 PM UTC+1, The Other Mike wrote:



If the government keep their stupid fingers out, it won't be long before appliances with this feature are available for an extra £5.

No you'll be entered into a free prize draw....





An 8 bit cpu can respond to frequency,



Not that easily, and I doubt using that method would be very successful.



its not hard to divide the clock frequency down to 50Hz ..



But you need a dedicated clock you can;t use the average MPUs clock as it's too inaccurate, you need a proper RTC, you do know that computers keep pretty crap time unless they get it from a server.

You wouldn;t use that method anyway as you need to mearuce the actual frequency of teh main not simulate it.

and time the period from local zero crossing to mains zero crossing, and log the latest value to see how far it moves.

Not necessary.



All one need do is

a) xtal control the cpu clock, an xtal with no oven is more than accurate enough to read 50Hz +/- 0.1%.

XTAL DO NOT READ FREQUENCIES and niether do CPUs.

The average watch cyrstal is 32.768 KHz, which is how they divide down to 1Hz
2 ^22 .



b) count a divided version of the clock from one mains zero crossing to the next. Problem solved.

That's not the way to do it, you don;t need zerop crossing wither until you decide to switch something even then zero crossing has nothing to do with it.




The slight frequency spread of the xtals prevents all appliances going off at the same time.

That's not really relible, XTALS have a very high accuracy when made, but temperature and series as well as parellel capacitance play a part.


Far better to have teh aplience switched off on demand from the suplier than wait for the frequency to alter which would be difficult to measure cheaply.



well, thats what checking the frequency achieves. How would you do it cheaper?



Measure the frequency at the power station and if it's condered that power needs reducing lower the overall voltage supplied to the grid.



Voltage control would be quite unreliable, V swings about in normal healthy use for various reasons.

The reason the frquecy drops is because of load, if teh loads too high then switching stuff off reduces the load that is the chepaest way of doing things.


If yuo really need to switch things off then measure the frequency of the grid and if it's below what you see as a miniumium then send a single to turn off particular devices that are in yuor home that the smartmeter recognise.



So you're proposing that appliances have 2 way communications,

No they don;t need two way communication, any more than your TV does.




and that smart meters talk to each appliance in each house. Doable of course, but its more money, so not attractive.

Why is it more money ?


Be silly to have to measure the frequency of every device.



Either you measure locally or decide centrally and communicate. Do you think 2 way communication's cheaper?



Yes.



I'm struggling to see how enabling 2 way comms and playing with MACs is cheaper than a divider in the chip.

What do you mean by a divider in the chip, which chip are you refering to ?




Measuring low frequecies accuratly is more difficult than you think.

What you have to do is count cycles in one second yuod get perhaps 47 or 53 so you need to average it out especailly in times of high or low demand.

So you need to sample it for at least 10 seconds to giove you 0.1 resoultion and in that time the situation can change.



Its not hard at all, just time the number of clock cycles between 2 successive crossings.

Two crossing of what ?

You could average lots of counts but I don't believe there's a need to, a small percentage of mistimes is immaterial in practice. Simply averaging several yes or nos would be trivially easy.

Yes ot no's to what exactly .


Anyway it would be cheaper to have just one device measuring frequency rather than every electrical device each reading it. If I were designing such a thing it'd use teh smart meter to measure it rather than install the ciruitry in my kettle and fridge.freeze, TV cooker shower , washing machine, coffee maker storage heaters fires hair dryer etc.....



but you'd still need to install everything in the appliances,

Yes of course unless you turn the whole suply to tteh hosue off.


you'd only miss out the clock divider, which inside a custom single IC costs close to nothing.

NO need for it so why have it.


What I'd get manufactiers of such devices to do it allocate a specific number to each product a bit like a MAC address which my smart meter can locate and be able to either just switch off/on or reduce it's power.



more costs

minmal compared to other methods.




idf all 2KW+ kettles had a 1/2 power switch then my first try would be to turn those kettles is 1/2 power them, I wouldn't turn off motors or mmoving things such as food blenders.



I'd agree there. There are many things can be turned off or down if its ever worth it. Today its mostly not though.

I agree so why bother ?
As I said before better to turn off scotland with all those deep fat fryers ;-)






and send the appliance serial number down the wiring now and then, and the power co software will automatically knock £1 off the bill.

More expense loggign serial numbers etc.. no need for it, as someone would need to keep a database of serail numbers.


Too much hassle and no need for it.



The user needs some reason to spend the cost of the control unit. If I were offered 20% ROI I'd buy, for a prize draw I wouldnt.



You don;t need to you make it cheap enough that no one would bother



that'll happen, but only after its already being widely bought, ie produced on a mass scale, with all the upfront investments paid off. To get to that point its going to cost, so there must be a customer upside.

That's not how they'll do it, too much hassle and risks of fraud.



or you make it illegal to sell products without such things.



but then its a protected parasite, & the cost stays high.

That's what will happen you can;t buy cheap kettles that might be dangerous they are oulawed i.e not imported.

Just like cheapm whisky and other spirits yes we pay extra in tax for te3h privavlge of not being able to buy cheap fags or booze, same will go for the electrical alliancies.


We do this in the name of H&S, you can't normally buy appliences without leads, you have to buy them with the product or buy them seperatly.


I remmber the days when buying electrical equipment you HAD to purchse a lead or plug and put that on yuorself. Nowadays that's not possible for most people you can;t go and buy even a £5 kettle without a moulted lead.

You can't say IO'm not buying an electrical product that comes woth a free lead because i have plenty. I have about 150 IEC leads I'm not using in a box.



Firstly this isnt a H&S issue,

I didn;t say it was.

and there isnt anywhere near justification to force it on everyone.

And no reason to force peole to buy sugar in KG packets is there ?

Second, phones are beginning to be sold now without chargers, and with IEC leads so common theyre moderately likely to become optional with cheap appliances. Government interference gets in the way of progress more than it helps it.

What type of phone uses an IEC lead ?

whisky-dave wrote:
On Wednesday, May 1, 2013 2:54:09 PM UTC+1, wrote:
On Wednesday, May 1, 2013 1:54:36 PM UTC+1, whisky-dave wrote:
But you need a dedicated clock you can;t use the average MPUs clock as it's too inaccurate, you need a proper RTC, you do know that computers keep pretty crap time unless they get it from a server.
You wouldn;t use that method anyway as you need to mearuce the actual frequency of teh main not simulate it.
and time the period from local zero crossing to mains zero crossing, and log the latest value to see how far it moves.
Not necessary.


All one need do is

a) xtal control the cpu clock, an xtal with no oven is more than accurate enough to read 50Hz +/- 0.1%.

XTAL DO NOT READ FREQUENCIES and niether do CPUs.

No, but you can use even the cheapest CPU to count clock cycles with a
smidgeon of machine code. Add an external circuit to flag zero crossings
of the mains waveform, and it is then trivial to calculate the mains
frequency. It is also trivial to write a prgram and design a circuit
that will automatically turn off a load if the frequency drops below a
certain level.

A cheap resonator clock is well within the accuracy meeded for this
application.


b) count a divided version of the clock from one mains zero crossing to the next. Problem solved.

That's not the way to do it, you don;t need zerop crossing wither until you decide to switch something even then zero crossing has nothing to do with it.

Wrong. Counting zero crossings and comparing the timing to a refrence
frequency, such as the clock controlling a microprocessor is the easiest
way to work out the frequency of a signal,especially the relativiely
pure sine wave that comes down the mains supply.


The slight frequency spread of the xtals prevents all appliances going off at the same time.

That's not really relible, XTALS have a very high accuracy when made, but temperature and series as well as parellel capacitance play a part.

Wow, you got something right. Even after aging and cooking, cheap
crystal and ceramic resonator frequencies are accurate to within not too
many parts per million. You're trying to check frequency stability of
the supply to within parts per thousand.

If yuo really need to switch things off then measure the frequency of the grid and if it's below what you see as a miniumium then send a single to turn off particular devices that are in yuor home that the smartmeter recognise.


So you're proposing that appliances have 2 way communications,

No they don;t need two way communication, any more than your TV does.

They do, otherwise how does the smart meter know what's switched on to
turn off? Minimum is a "Hello, controller, I am XXXXXXX" when switched
on, and "Goodbye from XXXXXXX" when turned off manually, and the
capability to receive "XXXXXXX Turn off now" and "XXXXXX Turn on now".

and that smart meters talk to each appliance in each house. Doable of course, but its more money, so not attractive.

Why is it more money ?

More complex circuitry. the frequency measuring can be done for about a
pound a unit by the maker, and if there's already a microprocessor in
the unit, it comes down to a few pence once the design costs have been
written off, the communications requires about a fiver.

Be silly to have to measure the frequency of every device.


Either you measure locally or decide centrally and communicate. Do you think 2 way communication's cheaper?


Yes.


I'm struggling to see how enabling 2 way comms and playing with MACs is cheaper than a divider in the chip.

What do you mean by a divider in the chip, which chip are you refering to ?

The cheap, 4 or 8 bit CPU in the appliance. A new use for a Z80 at last....


Measuring low frequecies accuratly is more difficult than you think.
What you have to do is count cycles in one second yuod get perhaps 47 or 53 so you need to average it out especailly in times of high or low demand.
So you need to sample it for at least 10 seconds to giove you 0.1 resoultion and in that time the situation can change.


Its not hard at all, just time the number of clock cycles between 2 successive crossings.

Two crossing of what ?

Zero voltage of the supply in this case.

You could average lots of counts but I don't believe there's a need to, a small percentage of mistimes is immaterial in practice. Simply averaging several yes or nos would be trivially easy.

Yes ot no's to what exactly .

Yes, the frequency is too low, no it isn't.

Anyway it would be cheaper to have just one device measuring frequency rather than every electrical device each reading it. If I were designing such a thing it'd use teh smart meter to measure it rather than install the ciruitry in my kettle and fridge.freeze, TV cooker shower , washing machine, coffee maker storage heaters fires hair dryer etc.....


but you'd still need to install everything in the appliances,

Yes of course unless you turn the whole suply to tteh hosue off.

?\The unit would be installed in the factory, with an option to fit it
to older machinery as well. To retrofit it, the only work needed in the
houseis to unplug the appliance. Your way means installing a new meter,
which *does* require disconnecting the supply.



idf all 2KW+ kettles had a 1/2 power switch then my first try would be to turn those kettles is 1/2 power them, I wouldn't turn off motors or mmoving things such as food blenders.


I'd agree there. There are many things can be turned off or down if its ever worth it. Today its mostly not though.

I agree so why bother ?
As I said before better to turn off scotland with all those deep fat fryers ;-)

You'll have Scotty on you before you know it if you suggest that.


--
Tciao for Now!

John.

On 1 May, 16:04, whisky-dave wrote:


a) xtal control the cpu clock, an xtal with no oven is more than accurate enough to read 50Hz +/- 0.1%.

XTAL DO NOT READ FREQUENCIES and niether do CPUs.

You need to take some time out and get a clue. The Xtal drives the MPU
clock at a known frequency. The MPU then measures the time different
between zero crossings. Some simple math is all that is required.


The average watch cyrstal is 32.768 KHz, which is how they divide down to 1Hz
2 ^22 .

And? MPUs generally run a lot faster than this except when in low
power mode. A typical modern PIC can use two different crystals for
low power and full on. The former typically being a watch crystal, the
latter 8MHZ, say, maybe with a 4x PLL.


b) count a divided version of the clock from one mains zero crossing to the next. Problem solved.

That's not the way to do it, you don;t need zerop crossing wither until you decide to switch something even then zero crossing has nothing to do with it.

Measuring zero crossings is how you measure frequency.

The slight frequency spread of the xtals prevents all appliances going off at the same time.

That's not really relible, XTALS have a very high accuracy when made, but temperature and series as well as parellel capacitance play a part.

And? What sort of accuracy do you think you need to detect the mains
going awry?


So you're proposing that appliances have 2 way communications,

No they don;t need two way communication, any more than your TV does.

So thay can be instructed when to tirn on/off.


I'm struggling to see how enabling 2 way comms and playing with MACs is cheaper than a divider in the chip.

What do you mean by a divider in the chip, which chip are you refering to ?

The clock divider in the MPU. Or, more simply, a counter that counts
cycles of the MPUs clcok between mains zero crossongs.


Its not hard at all, just time the number of clock cycles between 2 successive crossings.

Two crossing of what ?

Oh FFS! MAINS ZERO CROSSINGS.

MBQ

On May 1, 9:52*am, Tim Streater wrote:
In article
,

*harry wrote:
If each appliance is fitted with a "smart device", then no changes are
needed to the home wiring.
I would have thought is better to have "essential" and
"non-essential" circuits in every house.

And you think the teenagers are going to remember which socket to plug
something in to? Or the average person, come to that.

You think anyone is going to convert their existing house to that - put
all your furniture in storage, move out, have all the walls bashed
around to have a second set of cabling installed, replaster, complete
redecoration, move back in.

Dream on.

You are a very ignorant person.
This has been done for years in hospitals because the emergency
generators are often not large enough to meet the full load.
Essential sockets are usually red.
In acute wards, there are no non-essential sockets.
Most essential equipment is permanently connected anyway.

On Wednesday, May 1, 2013 4:26:14 PM UTC+1, John Williamson wrote:
whisky-dave wrote:

On Wednesday, May 1, 2013 2:54:09 PM UTC+1, wrote:

On Wednesday, May 1, 2013 1:54:36 PM UTC+1, whisky-dave wrote:

But you need a dedicated clock you can;t use the average MPUs clock as it's too inaccurate, you need a proper RTC, you do know that computers keep pretty crap time unless they get it from a server.

You wouldn;t use that method anyway as you need to mearuce the actual frequency of teh main not simulate it.

and time the period from local zero crossing to mains zero crossing, and log the latest value to see how far it moves.

Not necessary.





All one need do is



a) xtal control the cpu clock, an xtal with no oven is more than accurate enough to read 50Hz +/- 0.1%.



XTAL DO NOT READ FREQUENCIES and niether do CPUs.



No, but you can use even the cheapest CPU to count clock cycles with a

smidgeon of machine code.

Why count clock cycles ?


Add an external circuit to flag zero crossings

of the mains waveform,

why would you need that ?


and it is then trivial to calculate the mains

frequency. It is also trivial to write a prgram and design a circuit

that will automatically turn off a load if the frequency drops below a

certain level.

yes it is but is that what you want.., probbaly not you'd want flexability if you're controling things with smart meters.


A cheap resonator clock is well within the accuracy meeded for this

application.

Yes I know but that's not what required yuo need contol or rather they do.

What they also what which no on eseems to realise is have the ability to turn off yuor aplinces should you not pay yuor bill, legally I don;t think they cvan just cut you off without going through a lot of hassle but if you don;t pay and they switch yuor kettle down to half power ........



b) count a divided version of the clock from one mains zero crossing to the next. Problem solved.



That's not the way to do it, you don;t need zerop crossing wither until you decide to switch something even then zero crossing has nothing to do with it.



Wrong. Counting zero crossings and comparing the timing to a refrence

frequency, such as the clock controlling a microprocessor is the easiest

way to work out the frequency of a signal,especially the relativiely

pure sine wave that comes down the mains supply.

Good you know it's a sine wave which will change in amplitude as well as fequency which makes zero crossing more difficult and less useful.



The slight frequency spread of the xtals prevents all appliances going off at the same time.



That's not really relible, XTALS have a very high accuracy when made, but temperature and series as well as parellel capacitance play a part.



Wow, you got something right. Even after aging and cooking, cheap

crystal and ceramic resonator frequencies are accurate to within not too

many parts per million. You're trying to check frequency stability of

the supply to within parts per thousand.



If yuo really need to switch things off then measure the frequency of the grid and if it's below what you see as a miniumium then send a single to turn off particular devices that are in yuor home that the smartmeter recognise.





So you're proposing that appliances have 2 way communications,



No they don;t need two way communication, any more than your TV does.



They do, otherwise how does the smart meter know what's switched on to

turn off?

You send an off signal, same as they do when BBC3 goes off line, I don;t need to send a signal back to the BBC.


Minimum is a "Hello, controller, I am XXXXXXX" when switched

on, and "Goodbye from XXXXXXX" when turned off manually, and the

capability to receive "XXXXXXX Turn off now" and "XXXXXX Turn on now".

Not needed.

Why would yuor kettle need to tell anyone it's turned off or on. ?




and that smart meters talk to each appliance in each house. Doable of course, but its more money, so not attractive.



Why is it more money ?



More complex circuitry. the frequency measuring can be done for about a

pound a unit by the maker,

So ONE POUND for the whole house as it will be put in the smart meter.
If we know the national grid is runnoing at 49Hz why both measuring it in each aplince in each house in the country ?


and if there's already a microprocessor in

the unit, it comes down to a few pence once the design costs have been

written off, the communications requires about a fiver.

Not evenm that as USB or TCP/IP cound be used.




Be silly to have to measure the frequency of every device.





Either you measure locally or decide centrally and communicate. Do you think 2 way communication's cheaper?





Yes.





I'm struggling to see how enabling 2 way comms and playing with MACs is cheaper than a divider in the chip.

Because everything is already in place and dessigned.



What do you mean by a divider in the chip, which chip are you refering to ?



The cheap, 4 or 8 bit CPU in the appliance. A new use for a Z80 at last.....

Why a divider what would that acheive ?



Measuring low frequecies accuratly is more difficult than you think.

What you have to do is count cycles in one second yuod get perhaps 47 or 53 so you need to average it out especailly in times of high or low demand.

So you need to sample it for at least 10 seconds to giove you 0.1 resoultion and in that time the situation can change.





Its not hard at all, just time the number of clock cycles between 2 successive crossings.

Which would be about 1 but maybe ther;e s two zero crossing per cycle or period depends how you choose to count them.





Two crossing of what ?



Zero voltage of the supply in this case.

Two during 1 cycle or 1 per cycle ?




You could average lots of counts but I don't believe there's a need to, a small percentage of mistimes is immaterial in practice. Simply averaging several yes or nos would be trivially easy.


Yes ot no's to what exactly .



Yes, the frequency is too low, no it isn't.

yuo'll have to count it first and that takes time at such low frequencies.



Anyway it would be cheaper to have just one device measuring frequency rather than every electrical device each reading it. If I were designing such a thing it'd use teh smart meter to measure it rather than install the ciruitry in my kettle and fridge.freeze, TV cooker shower , washing machine, coffee maker storage heaters fires hair dryer etc.....





but you'd still need to install everything in the appliances,



Yes of course unless you turn the whole suply to tteh hosue off.



?\The unit would be installed in the factory,

what unit what factory ?

with an option to fit it

to older machinery as well. To retrofit it, the only work needed in the

houseis to unplug the appliance. Your way means installing a new meter,

which *does* require disconnecting the supply.

Yes the meter people come around and install a new meter free of chrge.



idf all 2KW+ kettles had a 1/2 power switch then my first try would be to turn those kettles is 1/2 power them, I wouldn't turn off motors or mmoving things such as food blenders.





I'd agree there. There are many things can be turned off or down if its ever worth it. Today its mostly not though.

To who....
I'm not sure it'd be worth doing this sort of thing, but some think the smart meters are goong to contol everything even toothbrushes, my toothbrush is wireless BTW, I'd like to say b;luetooth but I'm not totally sure it uses that methode, if it's cheap enough to put into a toothbrush why not a kettle or a TV or fridge freezer ?


I agree so why bother ?

As I said before better to turn off scotland with all those deep fat fryers ;-)



You'll have Scotty on you before you know it if you suggest that.

Lots of sciotties I'd assume although I doubt they'd catch me





--

Tciao for Now!



John.

On May 1, 10:40*am, Huge wrote:
On 2013-05-01, Tim Streater wrote:









In article
,
*harry wrote:

If each appliance is fitted with a "smart device", then no changes are
needed to the home wiring.
I would have thought is better to have "essential" and
"non-essential" circuits in every house.

And you think the teenagers are going to remember which socket to plug
something in to? Or the average person, come to that.

You think anyone is going to convert their existing house to that - put
all your furniture in storage, move out, have all the walls bashed
around to have a second set of cabling installed, replaster, complete
redecoration, move back in.

Dream on.

I've looked at 2 houses now that have parallel wiring systems for 110V and
BFO transformers tucked away somewhere. Most odd. I would have thought it
would have been *much* cheaper for American ex-pats to throw away their
electrical appliances and buy new ones here, and get a proper washing
machine into the bargain.



They get all their stuff transported for free. Most large power using
equipment is 220 volts anyway. Only small stuff is 110volts.

This included their cars. They used to bring over American Classics
and sell them at a profit. Mustangs Cadillacs etc.

Then they'd buy a Brit/European classic (Jag, Aston Martin Ferrari
etc) & have that transported back for free to sell at another profit.

whisky-dave wrote:
A lot of inane replies to sensible explanations

You really don't have a clue, do you?

--
Tciao for Now!

John.

O
I'm struggling to see how enabling 2 way comms and playing with MACs is cheaper than a divider in the chip.

Measuring low frequecies accuratly is more difficult than you think.
What you have to do is count cycles in one second yuod get perhaps 47 or 53 so you need to average it out especailly in times of high or low demand.
So you need to sample it for at least 10 seconds to giove you 0.1 resoultion and in that time the situation can change.

Its not hard at all, just time the number of clock cycles between 2 successive crossings. You could average lots of counts but I don't believe there's a need to, a small percentage of mistimes is immaterial in practice. Simply averaging several yes or nos would be trivially easy.

Anyway it would be cheaper to have just one device measuring frequency rather than every electrical device each reading it. If I were designing such a thing it'd use teh smart meter to measure it rather than install the ciruitry in my kettle and fridge.freeze, TV cooker shower , washing machine, coffee maker storage heaters fires hair dryer etc.....

but you'd still need to install everything in the appliances, you'd only miss out the clock divider, which inside a custom single IC costs close to nothing.

What I'd get manufactiers of such devices to do it allocate a specific number to each product a bit like a MAC address which my smart meter can locate and be able to either just switch off/on or reduce it's power.

more costs

idf all 2KW+ kettles had a 1/2 power switch then my first try would be to turn those kettles is 1/2 power them, I wouldn't turn off motors or mmoving things such as food blenders.

I'd agree there. There are many things can be turned off or down if its ever worth it. Today its mostly not though.

and send the appliance serial number down the wiring now and then, and the power co software will automatically knock £1 off the bill.
Too much hassle and no need for it.
The user needs some reason to spend the cost of the control unit. If I were offered 20% ROI I'd buy, for a prize draw I wouldnt.
You don;t need to you make it cheap enough that no one would bother

that'll happen, but only after its already being widely bought, ie produced on a mass scale, with all the upfront investments paid off. To get to that point its going to cost, so there must be a customer upside.

or you make it illegal to sell products without such things.

but then its a protected parasite, & the cost stays high.

We do this in the name of H&S, you can't normally buy appliences without leads, you have to buy them with the product or buy them seperatly.
I remmber the days when buying electrical equipment you HAD to purchse a lead or plug and put that on yuorself. Nowadays that's not possible for most people you can;t go and buy even a £5 kettle without a moulted lead.
You can't say IO'm not buying an electrical product that comes woth a free lead because i have plenty. I have about 150 IEC leads I'm not using in a box.

Firstly this isnt a H&S issue, and there isnt anywhere near justification to force it on everyone. Second, phones are beginning to be sold now without chargers, and with IEC leads so common theyre moderately likely to become optional with cheap appliances. Government interference gets in the way of progress more than it helps it.

NT

Better to work the system on voltage fluctuations than frequency.
If the voltage drops, reduce the load by what ever means you decide
on. When it rises the cut off loads can be reconnected.
Much easier.

harry wrote:
On May 1, 9:52 am, Tim Streater wrote:
In article
,

harry wrote:
If each appliance is fitted with a "smart device", then no changes are
needed to the home wiring.
I would have thought is better to have "essential" and
"non-essential" circuits in every house.
And you think the teenagers are going to remember which socket to plug
something in to? Or the average person, come to that.

You think anyone is going to convert their existing house to that - put
all your furniture in storage, move out, have all the walls bashed
around to have a second set of cabling installed, replaster, complete
redecoration, move back in.

Dream on.

You are a very ignorant person.
This has been done for years in hospitals because the emergency
generators are often not large enough to meet the full load.
Essential sockets are usually red.
In acute wards, there are no non-essential sockets.
Most essential equipment is permanently connected anyway.

In hospitals, the sockets with a protected supply are installed at build
time.

It would cost very little to put such sockets into new build housing,
but it wold take decades to penetrate the market to any noticeable
degree. To retrofit such sockets would mean, as has been suggested, a
complete rewire of any existing house.

Doing it later costs a fortune and severely disrupts the area being
worked on (Typically a ward or block) unless that area is being
refurbished anyway.


--
Tciao for Now!

John.

harry wrote:

Better to work the system on voltage fluctuations than frequency.
If the voltage drops, reduce the load by what ever means you decide
on. When it rises the cut off loads can be reconnected.
Much easier.

Yes, but much less effective.

There are a *lot* of places in this Country where voltage varies wildly
even under normal load conditions, and there are a *lot* of automatic
tap changers in substations and at the top of poles which try to
maintain the correct voltage. These would all have to be either adjusted
or overridden to do what you suggest. On the other hand, the frequency
is generally stable except under conditions of grid overload, and a
frequency drop is easily detected with very few false alarms.

If you plot mains frequency against time with enough resolution, you can
actually work out when popular TV programmes end by the frequency dip as
millions of kettles are turned on. You'd be hard pushed to do the same
by checking the Grid voltages.


--
Tciao for Now!

John.

On 1 May, 17:10, whisky-dave wrote:
On Wednesday, May 1, 2013 4:26:14 PM UTC+1, John Williamson wrote:
Why count clock cycles ?

What else do you think a timer in an MPU does?

Add an external circuit to flag zero crossings

of the mains waveform,

why would you need that ?

Because that's how you measure the frequency. You do know that
frequency is the inverse of period, don't you? That, the period can be
measured with the timer peripheral included in virtually every modern
MPU and that such timers work by counting cycles of the MPU clock.

No, I'm beginning to think you don't. I'm beginning to think you don't
have clue.



Good you know it's a sine wave which will change in amplitude as well as fequency which makes zero crossing more difficult and less useful.

A zero crossing is a zero crossing regardless of amplitude. The change
in frequency is what you are measuring.


You send an off signal, same as they do when BBC3 goes off line, I don;t need to send a signal back to the BBC.



Two crossing of what ?

Zero voltage of the supply in this case.

Two during 1 cycle or 1 per cycle ?

It's sufficient to measure the half-period between two zero crossings.

You could average lots of counts but I don't believe there's a need to, a small percentage of mistimes is immaterial in practice. Simply averaging several yes or nos would be trivially easy.
Yes ot no's to what exactly .

Yes, the frequency is too low, no it isn't.

yuo'll have to count it first and that takes time at such low frequencies.

Not long. One second will give you the average over 50 cycles. That's
more than fast enough and accurate enough.

MBQ

On 01/05/13 17:42, John Williamson wrote:
harry wrote:

Better to work the system on voltage fluctuations than frequency.
If the voltage drops, reduce the load by what ever means you decide
on. When it rises the cut off loads can be reconnected.
Much easier.

Yes, but much less effective.

There are a *lot* of places in this Country where voltage varies
wildly even under normal load conditions, and there are a *lot* of
automatic tap changers in substations and at the top of poles which
try to maintain the correct voltage. These would all have to be either
adjusted or overridden to do what you suggest. On the other hand, the
frequency is generally stable except under conditions of grid
overload, and a frequency drop is easily detected with very few false
alarms.

If you plot mains frequency against time with enough resolution, you
can actually work out when popular TV programmes end by the frequency
dip as millions of kettles are turned on. You'd be hard pushed to do
the same by checking the Grid voltages.


local voltage tells you what you or your street is doing. Frequency
tells you what the whole GRID is doing.


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers.

On 30/04/2013 20:51, Ian Jackson wrote:
In message , Andy Champ
writes
Yes. And?

If you get an increased load, surely you can maintain speed by
reducing the excitation current - can't you?

This will result in a reduction of generator output voltage.

That's the idea. To reduce power consumption by reducing voltage, but
_without_ changing the frequency. Apparently the UK grid can't do it.

Andy

On 01/05/2013 11:09, Martin Brown wrote:
I still recall discovering how my Ronson electric razor was supposed to
work when I first visited the US. A crap design that relied on a 60Hz
mechanical resonance. I have used Braun or a wet shave ever since.

Last Braun I had had an interesting musical twist. When you turned it
off as the oscillation stopped it went up a few notes - almost as if it
had a natural 60Hz oscillation...

Use Philips now.

Andy

In message , Andy Champ
writes
On 30/04/2013 20:51, Ian Jackson wrote:
In message , Andy Champ
writes
Yes. And?

If you get an increased load, surely you can maintain speed by
reducing the excitation current - can't you?

This will result in a reduction of generator output voltage.

That's the idea. To reduce power consumption by reducing voltage, but
_without_ changing the frequency. Apparently the UK grid can't do it.

If you lower the voltage at the power station (instead of allowing the
frequency to drop), and somewhere down the line there are automatic
re-adjustments to try to maintain the correct voltage, more current will
be drawn from the power station. If the power station again reduces its
voltage, the same thing will happen again. Presumably it's all a careful
balancing act involving both voltage and frequency.
--
Ian

On Wednesday, May 1, 2013 4:04:00 PM UTC+1, whisky-dave wrote:
On Wednesday, May 1, 2013 2:54:09 PM UTC+1, wrote:
On Wednesday, May 1, 2013 1:54:36 PM UTC+1, whisky-dave wrote:
On Wednesday, May 1, 2013 12:21:38 PM UTC+1, wrote:
On Wednesday, May 1, 2013 11:11:28 AM UTC+1, whisky-dave wrote:
On Wednesday, May 1, 2013 12:33:51 AM UTC+1, wrote:
On Tuesday, April 30, 2013 11:35:49 PM UTC+1, The Other Mike wrote:


An 8 bit cpu can respond to frequency,

Not that easily, and I doubt using that method would be very successful.

its not hard to divide the clock frequency down to 50Hz ..

But you need a dedicated clock you can;t use the average MPUs clock as it's too inaccurate, you need a proper RTC, you do know that computers keep pretty crap time unless they get it from a server.
You wouldn;t use that method anyway as you need to mearuce the actual frequency of teh main not simulate it.
and time the period from local zero crossing to mains zero crossing, and log the latest value to see how far it moves.

Not necessary.

All one need do is
a) xtal control the cpu clock, an xtal with no oven is more than accurate enough to read 50Hz +/- 0.1%.

XTAL DO NOT READ FREQUENCIES and niether do CPUs.

You seem to have misunderstood a lot this time. CPUs read frequency by counting clock cycles from one mains waveform zero crossing to the next.

If for example the cpu ran on a 40MHz clock, and it was divided down to 10MHz for counting, then a 50Hz half wave would give a count of 10M/100 = 100,000. That would give it a resolution of 0.1 microsecond per 100th second, or 0.1%.


The average watch cyrstal is 32.768 KHz, which is how they divide down to 1Hz
2 ^22 .

yup

b) count a divided version of the clock from one mains zero crossing to the next. Problem solved.

That's not the way to do it, you don;t need zerop crossing wither until you decide to switch something even then zero crossing has nothing to do with it.

you've missed it there completely

The slight frequency spread of the xtals prevents all appliances going off at the same time.

That's not really relible,

yes it is

XTALS have a very high accuracy when made, but temperature and series as well as parellel capacitance play a part.


Far better to have teh aplience switched off on demand from the suplier than wait for the frequency to alter which would be difficult to measure cheaply.

well, thats what checking the frequency achieves. How would you do it cheaper?

Measure the frequency at the power station and if it's condered that power needs reducing lower the overall voltage supplied to the grid.

Voltage control would be quite unreliable, V swings about in normal healthy use for various reasons.

The reason the frquecy drops is because of load, if teh loads too high then switching stuff off reduces the load that is the chepaest way of doing things.

looks like we're back to agreeing on frequency control


If yuo really need to switch things off then measure the frequency of the grid and if it's below what you see as a miniumium then send a single to turn off particular devices that are in yuor home that the smartmeter recognise.

So you're proposing that appliances have 2 way communications,

No they don;t need two way communication, any more than your TV does.

How can an appliance tell the smart meter its MAC and listen for when to shut down without 2 way comms?


and that smart meters talk to each appliance in each house. Doable of course, but its more money, so not attractive.

Why is it more money ?

because it means 2 way comms. Simply reading frequency changes takes nothing more than a frequency divider in teh control chip, at a cost of so close to zero its not even noticeable.


Be silly to have to measure the frequency of every device.

Either you measure locally or decide centrally and communicate. Do you think 2 way communication's cheaper?

Yes.

I'm struggling to see how enabling 2 way comms and playing with MACs is cheaper than a divider in the chip.

What do you mean by a divider in the chip, which chip are you refering to ?

A frequency divider in the appliance controlling chip. 2 way comms can't come in anywhere near as cheap.


Measuring low frequecies accuratly is more difficult than you think.
What you have to do is count cycles in one second yuod get perhaps 47 or 53 so you need to average it out especailly in times of high or low demand.
So you need to sample it for at least 10 seconds to giove you 0.1 resoultion and in that time the situation can change.

Its not hard at all, just time the number of clock cycles between 2 successive crossings.

Two crossing of what ?

zero crossings of the mains

You could average lots of counts but I don't believe there's a need to, a small percentage of mistimes is immaterial in practice. Simply averaging several yes or nos would be trivially easy.

Yes ot no's to what exactly .

yes or no decisions to whether the mains freq is too low or not


Anyway it would be cheaper to have just one device measuring frequency rather than every electrical device each reading it. If I were designing such a thing it'd use teh smart meter to measure it rather than install the ciruitry in my kettle and fridge.freeze, TV cooker shower , washing machine, coffee maker storage heaters fires hair dryer etc.....

but you'd still need to install everything in the appliances,

Yes of course unless you turn the whole suply to tteh hosue off.

then youre upping the cost pointlessly


you'd only miss out the clock divider, which inside a custom single IC costs close to nothing.

NO need for it so why have it.

explained


What I'd get manufactiers of such devices to do it allocate a specific number to each product a bit like a MAC address which my smart meter can locate and be able to either just switch off/on or reduce it's power.

more costs

minmal compared to other methods.

sorry but no, not even close


idf all 2KW+ kettles had a 1/2 power switch then my first try would be to turn those kettles is 1/2 power them, I wouldn't turn off motors or mmoving things such as food blenders.

I'd agree there. There are many things can be turned off or down if its ever worth it. Today its mostly not though.
I agree so why bother ?
As I said before better to turn off scotland with all those deep fat fryers ;-)


and send the appliance serial number down the wiring now and then, and the power co software will automatically knock £1 off the bill.

More expense loggign serial numbers etc.. no need for it, as someone would need to keep a database of serail numbers.

Too much hassle and no need for it.

The user needs some reason to spend the cost of the control unit. If I were offered 20% ROI I'd buy, for a prize draw I wouldnt.

You don;t need to you make it cheap enough that no one would bother

that'll happen, but only after its already being widely bought, ie produced on a mass scale, with all the upfront investments paid off. To get to that point its going to cost, so there must be a customer upside.

That's not how they'll do it, too much hassle and risks of fraud.

or you make it illegal to sell products without such things.

but then its a protected parasite, & the cost stays high.

That's what will happen you can;t buy cheap kettles that might be dangerous they are oulawed i.e not imported.
Just like cheapm whisky and other spirits yes we pay extra in tax for te3h privavlge of not being able to buy cheap fags or booze, same will go for the electrical alliancies.

clearly thats not a reason to do this

We do this in the name of H&S, you can't normally buy appliences without leads, you have to buy them with the product or buy them seperatly.

I remmber the days when buying electrical equipment you HAD to purchse a lead or plug and put that on yuorself. Nowadays that's not possible for most people you can;t go and buy even a £5 kettle without a moulted lead..
You can't say IO'm not buying an electrical product that comes woth a free lead because i have plenty. I have about 150 IEC leads I'm not using in a box.
Firstly this isnt a H&S issue,
I didn;t say it was.
and there isnt anywhere near justification to force it on everyone.

And no reason to force peole to buy sugar in KG packets is there ?

so?

Second, phones are beginning to be sold now without chargers, and with IEC leads so common theyre moderately likely to become optional with cheap appliances. Government interference gets in the way of progress more than it helps it.

What type of phone uses an IEC lead ?

Are you drunk or something?


NT

On Wed, 1 May 2013 20:35:24 +0100, Ian Jackson
wrote:

In message , Andy Champ
writes
On 30/04/2013 20:51, Ian Jackson wrote:
In message , Andy Champ
writes
Yes. And?

If you get an increased load, surely you can maintain speed by
reducing the excitation current - can't you?

This will result in a reduction of generator output voltage.

That's the idea. To reduce power consumption by reducing voltage, but
_without_ changing the frequency. Apparently the UK grid can't do it.

If you lower the voltage at the power station (instead of allowing the
frequency to drop), and somewhere down the line there are automatic
re-adjustments to try to maintain the correct voltage, more current will
be drawn from the power station. If the power station again reduces its
voltage, the same thing will happen again. Presumably it's all a careful
balancing act involving both voltage and frequency.

The generator at the power station and the 400kV, 275kV and 132kV transmission
networks all run at or very close to their nominal voltages, always.

The adjustment for voltage us made on the distribution networks, usually on the
secondary side of transformers having 132kV on their primaries.


--

On Wednesday, May 1, 2013 7:39:37 PM UTC+1, Man at B&Q wrote:
On 1 May, 17:10, whisky-dave wrote:
On Wednesday, May 1, 2013 4:26:14 PM UTC+1, John Williamson wrote:


Add an external circuit to flag zero crossings
of the mains waveform,

Quite a minor point, I'd include the whole lot on one chip. The only externals would then be the switching relay, and a resistor/cap/diodes to create an LV supply from the mains.

The less thinking the cpu does, the smaller and cheaper it can be. The big obstacle to such a system is cost, and if the government keep their foolish fingers out the cost issue gets solved. If the government mandates it there will be zero motivation to sort the cost out, and every motivation to keep it exorbitant. £40 for a little custom cpu and a 5 discretes is certainly exorbitant.


Good you know it's a sine wave which will change in amplitude as well as fequency which makes zero crossing more difficult and less useful.

A zero crossing is a zero crossing regardless of amplitude. The change
in frequency is what you are measuring.

quite. Pass the mains signal through RC to eliminate hf junk, and feed it to a comparator in the IC, then you have 1 or 0 for the cpu to enjoy.


NT

On May 1, 5:32*pm, John Williamson
wrote:
harry wrote:
On May 1, 9:52 am, Tim Streater wrote:
In article
,

*harry wrote:
If each appliance is fitted with a "smart device", then no changes are
needed to the home wiring.
I would have thought is better to have "essential" and
"non-essential" circuits in every house.
And you think the teenagers are going to remember which socket to plug
something in to? Or the average person, come to that.

You think anyone is going to convert their existing house to that - put
all your furniture in storage, move out, have all the walls bashed
around to have a second set of cabling installed, replaster, complete
redecoration, move back in.

Dream on.

You are a very ignorant person.
This has been done for years in hospitals because the emergency
generators are often not large enough to meet the full load.
Essential sockets are usually red.
In acute wards, there are no non-essential sockets.
Most essential equipment is permanently connected anyway.

In hospitals, the sockets with a protected supply are installed at build
time.

It would cost very little to put such sockets into new build housing,
but it wold take decades to penetrate the market to any noticeable
degree. To retrofit such sockets would mean, as has been suggested, a
complete rewire of any existing house.

Doing it later costs a fortune and severely disrupts the area being
worked on (Typically a ward or block) unless that area is being
refurbished anyway.

--
Tciao for Now!

John.

Most wiring is in trunking so not that difficult.

On May 1, 5:42*pm, John Williamson
wrote:
harry wrote:
Better to work the system on voltage fluctuations than frequency.
If the voltage drops, reduce the load by what ever means you decide
on. When it rises the cut off loads can be reconnected.
Much easier.

Yes, but much less effective.

There are a *lot* of places in this Country where voltage varies wildly
even under normal load conditions, and there are a *lot* of automatic
tap changers in substations and at the top of poles which try to
maintain the correct voltage. These would all have to be either adjusted
or overridden to do what you suggest. On the other hand, the frequency
is generally stable except under conditions of grid overload, and a
frequency drop is easily detected with very few false alarms.

If you plot mains frequency against time with enough resolution, you can
actually work out when popular TV programmes end by the frequency dip as
millions of kettles are turned on. You'd be hard pushed to do the same
by checking the Grid voltages.

--
Tciao for Now!

John.

The voltage "varies wildly" due to the load conditions.
Exactly what is trying to be determined, so it gives a good clue.
In the situation of microgenerators, (PV paeels etc) smart meters
could cut them off/shut them down if voltage rose locally indicating
an "over supply" situation.

Changing tappings on transformers does not help with any load changes.

BTW, I worked for years in an EB and never came a cross a local
transformer that changed tappings automatically. You'll have to
explain how that works.
None of the transformers round here do.

On May 1, 7:01*pm, Tim Streater wrote:
In article
,









*harry wrote:
On May 1, 9:52*am, Tim Streater wrote:
In article
,

*harry wrote:
If each appliance is fitted with a "smart device", then no changes are
needed to the home wiring.
I would have thought is better to have "essential" and
"non-essential" circuits in every house.

And you think the teenagers are going to remember which socket to plug
something in to? Or the average person, come to that.

You think anyone is going to convert their existing house to that - put
all your furniture in storage, move out, have all the walls bashed
around to have a second set of cabling installed, replaster, complete
redecoration, move back in.

Dream on.

You are a very ignorant person.
This has been done for years in hospitals because the emergency
generators are often not large enough to meet the full load.
Essential sockets are usually red.
In acute wards, there are no non-essential sockets.
Most essential equipment is permanently connected anyway.

I wasn't talking about commercial property, now was I? I was talking
about domestic.


We are talking about what might be done in the future.
Lots of these ideas being put about have been done for years in
commercial/industrial situations.

Eg, the thread on energy efficient pumps.
Which you average local plumber doesn't understand.

Condensing boilers were used commercially for years before they became
the domestic norm.

Heating system controls were used commercially long before domestic
use too.

All this stuff becomes viable domestically as the cost of fuel rises.

Lot of people round here need to get their heads out of their arses.
You actually need a zero energy house.

In article
,
harry wrote:
On May 1, 5:42 pm, John Williamson
wrote:
harry wrote:
Better to work the system on voltage fluctuations than frequency.
If the voltage drops, reduce the load by what ever means you decide
on. When it rises the cut off loads can be reconnected.
Much easier.

Yes, but much less effective.

There are a *lot* of places in this Country where voltage varies wildly
even under normal load conditions, and there are a *lot* of automatic
tap changers in substations and at the top of poles which try to
maintain the correct voltage. These would all have to be either adjusted
or overridden to do what you suggest. On the other hand, the frequency
is generally stable except under conditions of grid overload, and a
frequency drop is easily detected with very few false alarms.

If you plot mains frequency against time with enough resolution, you can
actually work out when popular TV programmes end by the frequency dip as
millions of kettles are turned on. You'd be hard pushed to do the same
by checking the Grid voltages.

--
Tciao for Now!

John.

The voltage "varies wildly" due to the load conditions.
Exactly what is trying to be determined, so it gives a good clue.
In the situation of microgenerators, (PV paeels etc) smart meters
could cut them off/shut them down if voltage rose locally indicating
an "over supply" situation.

Changing tappings on transformers does not help with any load changes.

BTW, I worked for years in an EB and never came a cross a local
transformer that changed tappings automatically. You'll have to
explain how that works.

when I worked as a student for SESEB most of them did. As did all the ones
in BBC tv centre - installed in 1961/2.
None of the transformers round here do.

--
From KT24

Using a RISC OS computer running v5.18

On May 1, 7:50*pm, The Natural Philosopher
wrote:
On 01/05/13 17:42, John Williamson wrote:







harry wrote:

Better to work the system on voltage fluctuations than frequency.
If the voltage drops, reduce the load by what ever means you decide
on. When it rises the cut off loads can be reconnected.
Much easier.

Yes, but much less effective.

There are a *lot* of places in this Country where voltage varies
wildly even under normal load conditions, and there are a *lot* of
automatic tap changers in substations and at the top of poles which
try to maintain the correct voltage. These would all have to be either
adjusted or overridden to do what you suggest. On the other hand, the
frequency is generally stable except under conditions of grid
overload, and a frequency drop is easily detected with very few false
alarms.

If you plot mains frequency against time with enough resolution, you
can actually work out when popular TV programmes end by the frequency
dip as millions of kettles are turned on. You'd be hard pushed to do
the same by checking the Grid voltages.

local voltage tells you what you or your street is doing. Frequency
tells you what the whole GRID is doing.

The street is what you need to know about.
The frequency business is ********.

If the voltage falls locally future smart meters could "report back"
and turn a few local wind turbines/PV panels on. ;-)

Or maybe some of these as they become common.
http://www.ecpower.co.uk/english/
(Co-generation)

Or maybe stored power in electric vehicle batteries.

This is what Smart Grid technology is about.
All these PV panels/small wind turbines will need controlling at some
point in the future. As they become more numerous, they can't be left
running uncontrolled as at the moment.

And they will also cut off non essential thing if needed.

Anybody who co-operates with all this will be rewarded. (As with PV/
other renewable power at the moment)

The important bit will be to monitor all this an there will be
financial inducements for people to do this. ie different prices for
importing/exporting power at different times.

We ain't seen nothing yet.

On May 1, 8:35*pm, Ian Jackson
wrote:
In message , Andy Champ
writesOn 30/04/2013 20:51, Ian Jackson wrote:
In message , Andy Champ
writes
Yes. And?

If you get an increased load, surely you can maintain speed by
reducing the excitation current - can't you?

This will result in a reduction of generator output voltage.

That's the idea. To reduce power consumption by reducing voltage, but
_without_ changing the frequency. Apparently the UK grid can't do it.

If you lower the voltage at the power station (instead of allowing the
frequency to drop), and somewhere down the line there are automatic
re-adjustments to try to maintain the correct voltage, more current will
be drawn from the power station. If the power station again reduces its
voltage, the same thing will happen again. Presumably it's all a careful
balancing act involving both voltage and frequency.
--
Ian

The object of the exercise is to maintain frequency and voltage at a
constant level. Ideally only current varies.

The problem is local voltage fluctuations.

Frequency is less important now than it was as there are fewer timing
devices rely on it.

On 02/05/2013 06:28, harry wrote:


The street is what you need to know about.
The frequency business is ********.

If the voltage falls locally future smart meters could "report back"
and turn a few local wind turbines/PV panels on. ;-)

Or maybe some of these as they become common.
http://www.ecpower.co.uk/english/
(Co-generation)

Or maybe stored power in electric vehicle batteries.

This is what Smart Grid technology is about.
All these PV panels/small wind turbines will need controlling at some
point in the future. As they become more numerous, they can't be left
running uncontrolled as at the moment.

And they will also cut off non essential thing if needed.

Anybody who co-operates with all this will be rewarded. (As with PV/
other renewable power at the moment)

The important bit will be to monitor all this an there will be
financial inducements for people to do this. ie different prices for
importing/exporting power at different times.

We ain't seen nothing yet.

Sounds wonderful - you have charged your electric vehicle using solar
panels, along comes a grid issue, so your vehicle battery is discharged
into the grid - along with any electricity your solar panels are producing.

End result, flat battery. And goodness knows what else unable to run due
to being cut off.

At least with a traditional power cut you don't lose that which you had.
At least with petrol they don't empty your tank during power cuts. Mind,
if they autostarted your little backup generator, and fed that
electricity into the grid as well, they could then empty your
generator's fuel tank quite nicely.

--
Rod

On 02/05/13 06:10, harry wrote:
On May 1, 7:01 pm, Tim Streater wrote:
In article
,









harry wrote:
On May 1, 9:52 am, Tim Streater wrote:
In article
,
harry wrote:
If each appliance is fitted with a "smart device", then no changes are
needed to the home wiring.
I would have thought is better to have "essential" and
"non-essential" circuits in every house.
And you think the teenagers are going to remember which socket to plug
something in to? Or the average person, come to that.
You think anyone is going to convert their existing house to that - put
all your furniture in storage, move out, have all the walls bashed
around to have a second set of cabling installed, replaster, complete
redecoration, move back in.
Dream on.
You are a very ignorant person.
This has been done for years in hospitals because the emergency
generators are often not large enough to meet the full load.
Essential sockets are usually red.
In acute wards, there are no non-essential sockets.
Most essential equipment is permanently connected anyway.
I wasn't talking about commercial property, now was I? I was talking
about domestic.

We are talking about what might be done in the future.
Lots of these ideas being put about have been done for years in
commercial/industrial situations.

Eg, the thread on energy efficient pumps.
Which you average local plumber doesn't understand.

Condensing boilers were used commercially for years before they became
the domestic norm.

Heating system controls were used commercially long before domestic
use too.

All this stuff becomes viable domestically as the cost of fuel rises.

Lot of people round here need to get their heads out of their arses.
You actually need a zero energy house.

or alternatively build ****loads of nuclear power stations and make
energy cheap enough so we don't have to spend billions on finding ways
to not use it.


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers.

On 02/05/13 06:32, harry wrote:
On May 1, 8:35 pm, Ian Jackson
wrote:
In message , Andy Champ
writesOn 30/04/2013 20:51, Ian Jackson wrote:
In message , Andy Champ
writes
Yes. And?
If you get an increased load, surely you can maintain speed by
reducing the excitation current - can't you?
This will result in a reduction of generator output voltage.
That's the idea. To reduce power consumption by reducing voltage, but
_without_ changing the frequency. Apparently the UK grid can't do it.
If you lower the voltage at the power station (instead of allowing the
frequency to drop), and somewhere down the line there are automatic
re-adjustments to try to maintain the correct voltage, more current will
be drawn from the power station. If the power station again reduces its
voltage, the same thing will happen again. Presumably it's all a careful
balancing act involving both voltage and frequency.
--
Ian
The object of the exercise is to maintain frequency and voltage at a
constant level. Ideally only current varies.

The problem is local voltage fluctuations.

Frequency is less important now than it was as there are fewer timing
devices rely on it.
Tell that to the German factories running synchronous motors that are
having f to intsall massive UPS/inverters because sudden fluctuations in
the mains frequency due to sun coming out/wind gust coming along are
destroying the machines the motors drive.

Some times I wonder if you actually believe all this ******** harry, or
whether its just you way of amusing yourself by pretending that you do,
or whether you actually are a SPIV and make a living out of selling
useless irrelevant technology to gullible people.



--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers.

On 01/05/2013 13:54, whisky-dave wrote:
Measuring low frequecies accuratly is more difficult than you think.
What you have to do is count cycles in one second yuod get perhaps 47 or 53 so you need to average it out especailly in times of high or low demand.
So you need to sample it for at least 10 seconds to giove you 0.1 resoultion and in that time the situation can change.

You ought to measure the time for 50 (or something) cycles instead. If
you time it at the zero crossing that doesn't move about much.

Even so - yes, it's hard, especially with a noisy waveform.

Andy

On 01/05/2013 14:54, wrote:
idf all 2KW+ kettles had a 1/2 power switch then my first try would be to turn those kettles is 1/2 power them, I wouldn't turn off motors or mmoving things such as food blenders.
I'd agree there. There are many things can be turned off or down if its ever worth it. Today its mostly not though.


Not much point. The kettle will consume the same number of joules, just
spread over 10 minutes instead of 5. I suppose it might help the ad
break, but at the cost of making the viewer miss the beginning of the
next bit.

In fact it will probably consume very slightly _more_ owing to heat loss
through the casing.

Andy

On 01/05/2013 20:35, Ian Jackson wrote:
In message , Andy Champ
writes
On 30/04/2013 20:51, Ian Jackson wrote:
In message , Andy Champ
writes
Yes. And?

If you get an increased load, surely you can maintain speed by
reducing the excitation current - can't you?

This will result in a reduction of generator output voltage.

That's the idea. To reduce power consumption by reducing voltage, but
_without_ changing the frequency. Apparently the UK grid can't do it.

If you lower the voltage at the power station (instead of allowing the
frequency to drop), and somewhere down the line there are automatic
re-adjustments to try to maintain the correct voltage, more current will
be drawn from the power station. If the power station again reduces its
voltage, the same thing will happen again. Presumably it's all a careful
balancing act involving both voltage and frequency.

I think as the generator slows the voltage drops, and this results in a
slightly lower consumption (not if taps are changed, or for a SMPSU, but
for resistive loads and some simple devices) The frequency drop has
B**** all effect. But ICBW.

Andy

On 01/05/2013 16:04, whisky-dave wrote:
The average watch cyrstal is 32.768 KHz, which is how they divide down to 1Hz
2 ^22 .

2^22 ~= 4M. I think you mean 2^15.

Andy