Aldi have an 800w (peak) 650w standard generator up for £59.99 this Sunday.

I've Googled back and got mixed responses.

Caravan discussion sites seem anti, but in 2009 this NG was cautiously in
favour.

I am considering this as an emergency power supply to the motorhome when
wild camping.
However I wouldn't want to incinerate an expensive Electroblok by using a
£60 generator with dodgy output.

So:

(1) Is the output smooth enough to feed into a 240V input for a caravan or
motorhome?
(2) If not, is there something reasonably priced to put between the
generator and the socket?

Honda is the quality answer but kicks off at around £1,000.
I note the references to farm sales but I suspect that farmers use the
robust generators in a pipe frame not the suitcase generators which are
easier to stow inside a camper or caravan.

Kipor is a cheap(ish) alternative but still at around £300 for a 1Kw peak
900w standard genny it is around 5 times the cost of this.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for just
under £180 which does compare favourably with £400 for a 2Kw generator from
Kipor.

All I really need is something to recharge the batteries without having to
run the engine.
So with 2 * 100 amp hour batteries to charge from 50% to 100% I would need
100 amps for an hour - well, lets say 50 amps for 2 hours.
Amps = watts/volts so
300 watts at 12 volts should give 25 amps charge current - 4 hours running.
600 watts at 12 volts should give 50 amps charge current (if the system
would take it) - 2 hours running.

All in all, a 600w generator run for a couple of hours in the morning should
be a reasonable alternative to a solar panel on the roof, given that 100w of
solar panel can cost £300 without the controller or fixing kit.

So , what does the team think?

Cheers

Dave R

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.

--
No plan survives contact with the enemy.
[Not even bunny]

Helmuth von Moltke the Elder

(\__/)
(='.'=)
(")_(")

On Jul 7, 8:44*pm, "David WE Roberts"
wrote:
snip snip

Aldi have an 800w (peak) 650w standard generator up for 59.99 this Sunday..

I am considering this as an emergency power supply to the motorhome when
wild camping.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for just
under 180 which does compare favourably with 400 for a 2Kw generator from
Kipor.

All I really need is something to recharge the batteries without having to
run the engine.
So with 2 * 100 amp hour batteries to charge from 50% to 100% I would need
100 amps for an hour - well, lets say 50 amps for 2 hours.
Amps = watts/volts so
300 watts at 12 volts should give 25 amps charge current - 4 hours running.
600 watts at 12 volts should give 50 amps charge current (if the system
would take it) - 2 hours running.

All in all, a 600w generator run for a couple of hours in the morning should
be a reasonable alternative to a solar panel on the roof, given that 100w of
solar panel can cost 300 without the controller or fixing kit.

So , what does the team think?

Cheers

Dave R

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.


If your chagrer is electronic swtched mode, just full wave rectify the
output from each gen, then conncet all 3 together. Check the genny
chassis is NOT connected to either L or N before doing this - it
probabyl wont be.

Another option I looked at for much teh same task was to build a big
nonrechargeable battery.


NT

On 07/07/2011 20:52, NT wrote:
On Jul 7, 8:44 pm, "David WE Roberts"
wrote:
snip snip

Aldi have an 800w (peak) 650w standard generator up for 59.99 this Sunday.

I am considering this as an emergency power supply to the motorhome when
wild camping.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for just
under 180 which does compare favourably with 400 for a 2Kw generator from
Kipor.

All I really need is something to recharge the batteries without having to
run the engine.
So with 2 * 100 amp hour batteries to charge from 50% to 100% I would need
100 amps for an hour - well, lets say 50 amps for 2 hours.
Amps = watts/volts so
300 watts at 12 volts should give 25 amps charge current - 4 hours running.
600 watts at 12 volts should give 50 amps charge current (if the system
would take it) - 2 hours running.

All in all, a 600w generator run for a couple of hours in the morning should
be a reasonable alternative to a solar panel on the roof, given that 100w of
solar panel can cost 300 without the controller or fixing kit.

So , what does the team think?

Cheers

Dave R

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.


If your chagrer is electronic swtched mode, just full wave rectify the
output from each gen, then conncet all 3 together. Check the genny
chassis is NOT connected to either L or N before doing this - it
probabyl wont be.


Wouldn't it be cheaper and less hassle "just" to get a bigger genny?

Another option I looked at for much teh same task was to build a big
nonrechargeable battery.


Why? If cost is an issue, how can that be cost effective?

On Thu, 7 Jul 2011 20:44:41 +0100, David WE Roberts wrote:

(1) Is the output smooth enough to feed into a 240V input for a caravan
or motorhome?

Do you have anything "sensitive" in the motorhome. Motors, lights,
heaters etc are not "sensitive". Electonics, TV etc, might be.

Honda is the quality answer but kicks off at around £1,000.
snip
Kipor is a cheap(ish) alternative but still at around £300 for a 1Kw
peak 900w standard genny it is around 5 times the cost of this.

They are probably invertor generators and will produce a decent
waveform. The "little stinky" Aldi two stroke will just be an
alternator and engine, the waveform may get distorted near capacity.
Little stinky will be that as well smelly by being a two stroke and
compared to the Honda/Kipor invertor range rather noisey.

Hmmm.......any way of linking the output of 3 of these together?

Not easyly. You can't simply wire them in parallel as I doubt the
load sharing woud be equal and the moment that you join two
non-synchrous sets together might be interesting as well. You can get
link kits for the Honda invertors.

So with 2 * 100 amp hour batteries to charge from 50% to 100% I would
need 100 amps for an hour - well, lets say 50 amps for 2 hours.
Amps = watts/volts so 300 watts at 12 volts should give 25 amps charge
current - 4 hours running. 600 watts at 12 volts should give 50 amps
charge current (if the system would take it) - 2 hours running.

The 12v out from most of these small set is normally only about 10A,
so you'd be looking at using the 240v out and a beefy battery
charger, which will add losses, say 25% overall.

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.

Yes but they don't come particularly cheap and the feed in isn't
quite the same as what you are wanting.

--
Cheers
Dave.

On Jul 7, 10:14*pm, Fredxx wrote:
On 07/07/2011 20:52, NT wrote:



On Jul 7, 8:44 pm, "David WE Roberts"
*wrote:
snip snip

Aldi have an 800w (peak) 650w standard generator up for 59.99 this Sunday.

I am considering this as an emergency power supply to the motorhome when
wild camping.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for just
under 180 which does compare favourably with 400 for a 2Kw generator from
Kipor.

All I really need is something to recharge the batteries without having to
run the engine.
So with 2 * 100 amp hour batteries to charge from 50% to 100% I would need
100 amps for an hour - well, lets say 50 amps for 2 hours.
Amps = watts/volts so
300 watts at 12 volts should give 25 amps charge current - 4 hours running.
600 watts at 12 volts should give 50 amps charge current (if the system
would take it) - 2 hours running.

All in all, a 600w generator run for a couple of hours in the morning should
be a reasonable alternative to a solar panel on the roof, given that 100w of
solar panel can cost 300 without the controller or fixing kit.

So , what does the team think?

Cheers

Dave R

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.

If your chagrer is electronic swtched mode, just full wave rectify the
output from each gen, then conncet all 3 together. Check the genny
chassis is NOT connected to either L or N before doing this - it
probabyl wont be.

Wouldn't it be cheaper and less hassle "just" to get a bigger genny?

Another option I looked at for much teh same task was to build a big
nonrechargeable battery.

Why? *If cost is an issue, how can that be cost effective?

A big battery costs peanuts compared to a generator. There's a wide
variety of chemistries available, IIRC the one that tempted me was
aluminium electrodes in what was it, soda? I dont remember the
electrolyte now.


NT

David WE Roberts wrote:

Aldi have an 800w (peak) 650w standard generator up for £59.99 this
Sunday.

I've Googled back and got mixed responses.

Caravan discussion sites seem anti, but in 2009 this NG was
cautiously in favour.

I am considering this as an emergency power supply to the motorhome
when wild camping. However I wouldn't want to incinerate an
expensive Electroblok by using a £60 generator with dodgy output.

Don't.

We have a Honda 600w gennie that's pretty damn good, giving exactly
what it says on the tin, and pretty clean, we've run laptops directly
from it when timing races etc ..

We tried one of these a year or so ago and it was reasonable when not
under too much load! When equipment was being used it laboured and
'hunting' speed changes made it appear even louder than it actually
was. We didn't dare attach the laptops to it 'cos of the speed
changes, so probably can't really comment on how 'clean' the output was
other than to say it didn't inspire confidence at all.

I think it's not the sort of gennie for anyone in a
caravan/motorhome/camping who has a need to run potentially voltage
sensitive equipment from it, or for anyone who cares about neighbours
and their very local, personal, environment .. the two-stroke is a bit
loud and definitely smelly. (personally I love 2t smells and sounds,
'specially racing 2t's, but this is the worst kind of 2t, like an angry
waso!)


--
Paul - xxx

On Fri, 8 Jul 2011 08:20:41 +0100, David WE Roberts wrote:

Yes, there are sensitive bits of kit including the Electroblok which is
some kind of fancy charge controller for the batteries and distribution
system so the input should really be, I guess, from a good quality
smoothed and regulated source.

Check with the maker, though they may cover their arse and say it has
to be connected to mains. Mind you some mains supplies can be pretty
ropey...

The big problem with these little gensets is regulation when the load
changes. They don't have enough grunt to maintain volts when the load
goes up and tend to overshoot when it drops. Under constant load
conditions they aren't too bad.

So - noisy, smelly, unregulated output.

Noisy compared to the Honda invertors which are *very* quiet... Not
noisy when compared to an open frame petrol set and positively
inaudible compared to an open frame diesel. B-)

Being a two stroke you do have the faff of mixing the fuel and oil.
Wonders if you can get scented two stroke oil, fresh mown grass?

I was impressed by an old 600W Honda (no longer made AFAICT) used by
another motor homer in France.

Probably not a lot different TBH.

--
Cheers
Dave.

David WE Roberts wrote:

So - noisy, smelly, unregulated output.
Thought it was too cheap to be suitable but thought I'd check just in
case. I was impressed by an old 600W Honda (no longer made AFAICT)
used by another motor homer in France.

Heh, I should have read through to here before my reply to the original
post ..

--
Paul - xxx

On 08/07/2011 09:06, NT wrote:
On Jul 7, 10:14 pm, wrote:
On 07/07/2011 20:52, NT wrote:



On Jul 7, 8:44 pm, "David WE Roberts"
wrote:
snip snip

Aldi have an 800w (peak) 650w standard generator up for 59.99 this Sunday.

I am considering this as an emergency power supply to the motorhome when
wild camping.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for just
under 180 which does compare favourably with 400 for a 2Kw generator from
Kipor.

All I really need is something to recharge the batteries without having to
run the engine.
So with 2 * 100 amp hour batteries to charge from 50% to 100% I would need
100 amps for an hour - well, lets say 50 amps for 2 hours.
Amps = watts/volts so
300 watts at 12 volts should give 25 amps charge current - 4 hours running.
600 watts at 12 volts should give 50 amps charge current (if the system
would take it) - 2 hours running.

All in all, a 600w generator run for a couple of hours in the morning should
be a reasonable alternative to a solar panel on the roof, given that 100w of
solar panel can cost 300 without the controller or fixing kit.

So , what does the team think?

Cheers

Dave R

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.

If your chagrer is electronic swtched mode, just full wave rectify the
output from each gen, then conncet all 3 together. Check the genny
chassis is NOT connected to either L or N before doing this - it
probabyl wont be.

Wouldn't it be cheaper and less hassle "just" to get a bigger genny?

Another option I looked at for much teh same task was to build a big
nonrechargeable battery.

Why? If cost is an issue, how can that be cost effective?

A big battery costs peanuts compared to a generator. There's a wide
variety of chemistries available, IIRC the one that tempted me was
aluminium electrodes in what was it, soda? I dont remember the
electrolyte now.


NT

Aluminium is £2.50 per kg at world prices, in practice you'll be paying
double this.

A Aluminium KOH batter gets 1300WH per kg. Hand waving guess.

So £2 per kWH

We also have to factor in that Al batteries degrade irrespective of
whether a current is drawn or not.

You can get a 850W genny from Machine Mart for just £100, ie just 40kg
of aluminium at world prices.

I don't feel quite as "tempted" as you!!

On 07/
Kipor is a cheap(ish) alternative but still at around £300 for a 1Kw
peak 900w standard genny it is around 5 times the cost of this.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for
just under £180 which does compare favourably with £400 for a 2Kw
generator from Kipor.


I have used several Kipor generators, and have checked the output
waveform on an oscilloscope under load, and can confirm that it is a
true sinewave, and remains in good shape until nearly full load (3kw
model checked). Even then the distortion is minimal.

I have ran many laptops, printers, chargers etc from them without issues.

AlanD wrote:
On 07/
Kipor is a cheap(ish) alternative but still at around £300 for a 1Kw
peak 900w standard genny it is around 5 times the cost of this.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for
just under £180 which does compare favourably with £400 for a 2Kw
generator from Kipor.


I have used several Kipor generators, and have checked the output
waveform on an oscilloscope under load, and can confirm that it is a true
sinewave, and remains in good shape until nearly full load (3kw model
checked). Even then the distortion is minimal.

I have ran many laptops, printers, chargers etc from them without issues.

We use one of the big diesel models. It's quiet, rugged and works
flawlessly with a huge range of equipment including running a commercial
microwave.

On Jul 8, 11:40*am, Fredxx wrote:
On 08/07/2011 09:06, NT wrote:



On Jul 7, 10:14 pm, *wrote:
On 07/07/2011 20:52, NT wrote:

On Jul 7, 8:44 pm, "David WE Roberts"
* *wrote:
snip snip

Aldi have an 800w (peak) 650w standard generator up for 59.99 this Sunday.

I am considering this as an emergency power supply to the motorhome when
wild camping.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for just
under 180 which does compare favourably with 400 for a 2Kw generator from
Kipor.

All I really need is something to recharge the batteries without having to
run the engine.
So with 2 * 100 amp hour batteries to charge from 50% to 100% I would need
100 amps for an hour - well, lets say 50 amps for 2 hours.
Amps = watts/volts so
300 watts at 12 volts should give 25 amps charge current - 4 hours running.
600 watts at 12 volts should give 50 amps charge current (if the system
would take it) - 2 hours running.

All in all, a 600w generator run for a couple of hours in the morning should
be a reasonable alternative to a solar panel on the roof, given that 100w of
solar panel can cost 300 without the controller or fixing kit.

So , what does the team think?

Cheers

Dave R

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.

If your chagrer is electronic swtched mode, just full wave rectify the
output from each gen, then conncet all 3 together. Check the genny
chassis is NOT connected to either L or N before doing this - it
probabyl wont be.

Wouldn't it be cheaper and less hassle "just" to get a bigger genny?

Another option I looked at for much teh same task was to build a big
nonrechargeable battery.

Why? *If cost is an issue, how can that be cost effective?

A big battery costs peanuts compared to a generator. There's a wide
variety of chemistries available, IIRC the one that tempted me was
aluminium electrodes in what was it, soda? I dont remember the
electrolyte now.

NT

Aluminium is 2.50 per kg at world prices, in practice you'll be paying
double this.

A Aluminium KOH batter gets 1300WH per kg. *Hand waving guess.

So 2 per kWH

We also have to factor in that Al batteries degrade irrespective of
whether a current is drawn or not.

You can get a 850W genny from Machine Mart for just 100, ie just 40kg
of aluminium at world prices.

I don't feel quite as "tempted" as you!!

Aluminium costs nothing in the form of drinks cans, just look in the
recycling box. There is no degradation when no current is drawn, the
plates are kept dry, only dipped in when power is wanted. If you dont
like the ali cells there are plenty of other options.


NT

On Jul 8, 11:48*am, AlanD wrote:
On 07/

Kipor is a cheap(ish) alternative but still at around £300 for a 1Kw
peak 900w standard genny it is around 5 times the cost of this.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for
just under £180 which does compare favourably with £400 for a 2Kw
generator from Kipor.

I have used several Kipor generators, and have checked the output
waveform on an oscilloscope under load, and can confirm that it is a
true sinewave, and remains in good shape until nearly full load (3kw
model checked). Even then the distortion is minimal.

I have ran many laptops, printers, chargers etc from them without issues.


Laptops couldnt care less about the waveform, and are tolerant of very
wide voltage swings too. You can feed them with 300v dc and they'll be
happy. What they dont tolerate so well is high voltage surges, and
this is one situation where surge absorbers have a genuine use.


NT

"Fredxx" wrote in message
...

Aluminium is £2.50 per kg at world prices, in practice you'll be paying
double this.

A Aluminium KOH batter gets 1300WH per kg. Hand waving guess.

So £2 per kWH

We also have to factor in that Al batteries degrade irrespective of
whether a current is drawn or not.

While I was at Marconi we were investigating Al batteries as standby in
exchanges.
They had a long life as the Al was not in the hydroxide until needed.
They were primary cells though and after use the hydroxide and Al were
replaced.
I don't think they were actually used but I don't know why (its not a
project I worked on).


You can get a 850W genny from Machine Mart for just £100, ie just 40kg of
aluminium at world prices.

I don't feel quite as "tempted" as you!!

NT wrote:
[snip]

Laptops couldnt care less about the waveform,

Utter ********. Many switched mode PSUs will fail within a short time of
being connected to the pseudo sine wave output from cheap inverters. They
are also intolerant of the output from cheap unregulated alternators.

and are tolerant of very
wide voltage swings too. You can feed them with 300v dc and they'll be
happy.

No that's ******** as well. Most will handle 90-270V AC only. The ones
that run on DC are at best 9-30V and have a four wire connection to the PSU
with a separate DC input. The cannot take DC on the AC input.

What they dont tolerate so well is high voltage surges, and

What I don't tolerate well is ********.

this is one situation where surge absorbers have a genuine use.

Yes, put one in your gob until the desire to talk **** goes away.

"Steve Firth" wrote in message
...
AlanD wrote:
On 07/
Kipor is a cheap(ish) alternative but still at around £300 for a 1Kw
peak 900w standard genny it is around 5 times the cost of this.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for
just under £180 which does compare favourably with £400 for a 2Kw
generator from Kipor.


I have used several Kipor generators, and have checked the output
waveform on an oscilloscope under load, and can confirm that it is a true
sinewave, and remains in good shape until nearly full load (3kw model
checked). Even then the distortion is minimal.

I have ran many laptops, printers, chargers etc from them without issues.

We use one of the big diesel models. It's quiet, rugged and works
flawlessly with a huge range of equipment including running a commercial
microwave.

I have one of the 2.5 kva generators that Aldi sold about 8 years ago for
£149. It has had periodic use as standby and a few weekends powering lights
at events. It runs everything in the house with no problem, but not all at
once mind. Computers, TVs, Central heating, Kettle and of course lighting.
The only problem I can't solve is that on very low loads the engine has
decided to constantly hunts up and down on the last two occasions I have
used it. When used to power the house I find that switching all the outside
lights on is enough load to keep it stable, and that helps wind up the
neighbours that we have power and they don't :-)

Mike

On 08/07/2011 13:10, NT wrote:
On Jul 8, 11:48 am, wrote:
On 07/

Kipor is a cheap(ish) alternative but still at around £300 for a 1Kw
peak 900w standard genny it is around 5 times the cost of this.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for
just under £180 which does compare favourably with £400 for a 2Kw
generator from Kipor.

I have used several Kipor generators, and have checked the output
waveform on an oscilloscope under load, and can confirm that it is a
true sinewave, and remains in good shape until nearly full load (3kw
model checked). Even then the distortion is minimal.

I have ran many laptops, printers, chargers etc from them without issues.


Laptops couldnt care less about the waveform, and are tolerant of very
wide voltage swings too. You can feed them with 300v dc and they'll be
happy. What they dont tolerate so well is high voltage surges, and
this is one situation where surge absorbers have a genuine use.


In the good old days when power factor wasn't an issue I can well
believe that. Current rules have a harmonic content which means that AC
current must faithfully follow AC voltage. I'd be surprised if a laptop
power supply would work with DC - BICBW.

On Fri, 08 Jul 2011 16:06:07 +0100, MuddyMike wrote:

"Steve Firth" wrote in message
news:2054339257331817740.517251%steve%-
...
AlanD wrote:
On 07/
Kipor is a cheap(ish) alternative but still at around £300 for a 1Kw
peak 900w standard genny it is around 5 times the cost of this.

Hmmm.......any way of linking the output of 3 of these together? That
would give 2.4kw (peak) 1.95kw (standard) of generating power for
just under £180 which does compare favourably with £400 for a 2Kw
generator from Kipor.


I have used several Kipor generators, and have checked the output
waveform on an oscilloscope under load, and can confirm that it is a
true sinewave, and remains in good shape until nearly full load (3kw
model checked). Even then the distortion is minimal.

I have ran many laptops, printers, chargers etc from them without
issues.

We use one of the big diesel models. It's quiet, rugged and works
flawlessly with a huge range of equipment including running a
commercial microwave.

I have one of the 2.5 kva generators that Aldi sold about 8 years ago
for £149. It has had periodic use as standby and a few weekends powering
lights at events. It runs everything in the house with no problem, but
not all at once mind. Computers, TVs, Central heating, Kettle and of
course lighting. The only problem I can't solve is that on very low
loads the engine has decided to constantly hunts up and down on the last
two occasions I have used it. When used to power the house I find that
switching all the outside lights on is enough load to keep it stable,
and that helps wind up the neighbours that we have power and they don't
:-)

Mike


That's not unusual for the simpler generators with mechanical governors.
Modern electronic governors tend to give far better low load performance,
but they cost a lot more! You usually need to have a minimum load of
5-10% to keep a mechanical governor happy. If the set has been ok
previously then look for contamination somewhere in the fuel supply/carb
or a worn plug.

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info
Filtering everything posted from googlegroups to kill spam.

On Fri, 08 Jul 2011 16:06:28 +0100, Fredxx wrote:

On 08/07/2011 13:10, NT wrote:
On Jul 8, 11:48 am, wrote:
On 07/

Kipor is a cheap(ish) alternative but still at around £300 for a 1Kw
peak 900w standard genny it is around 5 times the cost of this.

Hmmm.......any way of linking the output of 3 of these together? That
would give 2.4kw (peak) 1.95kw (standard) of generating power for
just under £180 which does compare favourably with £400 for a 2Kw
generator from Kipor.

I have used several Kipor generators, and have checked the output
waveform on an oscilloscope under load, and can confirm that it is a
true sinewave, and remains in good shape until nearly full load (3kw
model checked). Even then the distortion is minimal.

I have ran many laptops, printers, chargers etc from them without
issues.


Laptops couldnt care less about the waveform, and are tolerant of very
wide voltage swings too. You can feed them with 300v dc and they'll be
happy. What they dont tolerate so well is high voltage surges, and this
is one situation where surge absorbers have a genuine use.


In the good old days when power factor wasn't an issue I can well
believe that. Current rules have a harmonic content which means that AC
current must faithfully follow AC voltage. I'd be surprised if a laptop
power supply would work with DC - BICBW.


Every SMPS front end rectifies the mains supply and gives it a bit of
smoothing before driving the mains side oscillator. I can't see any
reason why a stepped "sine" wave or poor power factor of the supply would
make any difference at all. Big spikes on the supply would probably kill
it, but that applies to so-called "clean" mains supplies too. Just put
some 275v L-N, L-E & N-E VDRs (belt and braces!) on the input to protect
against that.

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info
Filtering everything posted from googlegroups to kill spam.

Fredxx wrote:

In the good old days when power factor wasn't an issue I can well
believe that. Current rules have a harmonic content which means that AC
current must faithfully follow AC voltage. I'd be surprised if a laptop
power supply would work with DC - BICBW.

The BBC Micro had an SMPSU, Way back when, I knew someone who soldered
100 NiCads in series (housed in a length of drainpipe) with a 13A socket
on one end, it happily powered the BBC micro ... OK so it's not a modern
laptop.

On Jul 8, 1:41*pm, Steve Firth wrote:
NT wrote:

[snip]



Laptops couldnt care less about the waveform,

Utter ********. Many switched mode PSUs will fail within a short time of
being connected to the pseudo sine wave output from cheap inverters. They
are also intolerant of the output from cheap unregulated alternators.

and are tolerant of very
wide voltage swings too. You can feed them with 300v dc and they'll be
happy.

No that's ******** as well. *Most will handle 90-270V AC only. The ones
that run on DC are at best 9-30V and have a four wire connection to the PSU
with a separate DC input. The cannot take DC on the AC input.

What they dont tolerate so well is high voltage surges, and

What I don't tolerate well is ********.

this is one situation where surge absorbers have a genuine use.

Yes, put one in your gob until the desire to talk **** goes away.


Laptop supplies are always switched mode. Mains input goes thru a
bridge rec to reservoir cap(s), at which point its 330v dc. The
following switch mode supply can handle a wide voltage range, designed
tht way so it can handle 100 to 240v ac without a sswitch or risk of
damage. Whether you feed the beast with 120v ac, 240v ac, 170v dc or
330v dc doesnt make any difference to its operation.

Portabel gens are ill regulatde and inductive sources. Load dump can
kill some electronic items, and surge absorbers, which are a waste of
time on mains, actually have a use in this situation.

Provide some overlooked and relevant data, or dont, but grow up.


NT

Andy Burns wrote:

The BBC Micro had an SMPSU, Way back when, I knew someone who soldered
100 NiCads in series

Make that 200

(housed in a length of drainpipe) with a 13A socket
on one end, it happily powered the BBC micro ... OK so it's not a modern
laptop.

On Fri, 8 Jul 2011 13:37:53 -0700 (PDT), NT wrote:

Laptop supplies are always switched mode. Mains input goes thru a
bridge rec to reservoir cap(s), at which point its 330v dc. The
following switch mode supply can handle a wide voltage range, designed
tht way so it can handle 100 to 240v ac without a sswitch or risk of
damage. Whether you feed the beast with 120v ac, 240v ac, 170v dc or
330v dc doesnt make any difference to its operation.

Provided that the bridge rectifier diodes where speced for at least
100% duty cycle not just to handle the expected 50% when fed from AC.

--
Cheers
Dave.

On 08/07/2011 17:32, mick wrote:
On Fri, 08 Jul 2011 16:06:28 +0100, Fredxx wrote:

On 08/07/2011 13:10, NT wrote:
On Jul 8, 11:48 am, wrote:
On 07/

Kipor is a cheap(ish) alternative but still at around £300 for a 1Kw
peak 900w standard genny it is around 5 times the cost of this.

Hmmm.......any way of linking the output of 3 of these together? That
would give 2.4kw (peak) 1.95kw (standard) of generating power for
just under £180 which does compare favourably with £400 for a 2Kw
generator from Kipor.

I have used several Kipor generators, and have checked the output
waveform on an oscilloscope under load, and can confirm that it is a
true sinewave, and remains in good shape until nearly full load (3kw
model checked). Even then the distortion is minimal.

I have ran many laptops, printers, chargers etc from them without
issues.


Laptops couldnt care less about the waveform, and are tolerant of very
wide voltage swings too. You can feed them with 300v dc and they'll be
happy. What they dont tolerate so well is high voltage surges, and this
is one situation where surge absorbers have a genuine use.


In the good old days when power factor wasn't an issue I can well
believe that. Current rules have a harmonic content which means that AC
current must faithfully follow AC voltage. I'd be surprised if a laptop
power supply would work with DC - BICBW.


Every SMPS front end rectifies the mains supply and gives it a bit of
smoothing before driving the mains side oscillator. I can't see any
reason why a stepped "sine" wave or poor power factor of the supply would
make any difference at all. Big spikes on the supply would probably kill
it, but that applies to so-called "clean" mains supplies too. Just put
some 275v L-N, L-E& N-E VDRs (belt and braces!) on the input to protect
against that.


You're entirely mistaken. There are rules for the harmonic content of
current for supplies over 75W since 2001. IEC/EN61000-3-2 sets some
very strict rules which entirely rule out the use of simple AC
rectification using a standard bridge rectifier.

On 08/07/2011 20:48, Andy Burns wrote:
Fredxx wrote:

In the good old days when power factor wasn't an issue I can well
believe that. Current rules have a harmonic content which means that AC
current must faithfully follow AC voltage. I'd be surprised if a laptop
power supply would work with DC - BICBW.

The BBC Micro had an SMPSU, Way back when, I knew someone who soldered
100 NiCads in series (housed in a length of drainpipe) with a 13A socket
on one end, it happily powered the BBC micro ... OK so it's not a modern
laptop.


Given the age that wouldn't surprise me. Using a bridge rectifier to
produce the internal power supply is cheap and efficient.

There is a thought that the newer directives are counter productive
since they inherently produce less efficient solutions!

In article ,
Andy Burns wrote:
Fredxx wrote:

In the good old days when power factor wasn't an issue I can well
believe that. Current rules have a harmonic content which means that AC
current must faithfully follow AC voltage. I'd be surprised if a laptop
power supply would work with DC - BICBW.

The BBC Micro had an SMPSU, Way back when, I knew someone who soldered
100 NiCads in series (housed in a length of drainpipe) with a 13A socket
on one end, it happily powered the BBC micro ... OK so it's not a modern
laptop.

That seemed like hard work... Once upon a time, I used a BBC B to 'drive'
an experimental Automatic Guided Vehicle round a factory floor. The AGV
had a pair of 12V lead acid batterys and I just wired the 12V from the
battery into a 5V regulator and used that to power the unit. I think it
needed -5V for something, but I've forgotten what now but it seemed OK
without it! I'd have the AGV next to my workbench, plug the Beeb into a
monitor & the Econet, load up the software, then unplug it, sit on the
AGV and drive it round using the F keys for speed and arrows to steer
(ok, not quite automatic, but it was proof of concept

Gordon

On 11/07/2011 00:38, Steve Firth wrote:

And back to your cobblers. Yes, it does make a difference. Using DC for
example means that current only flows through half of the diodes in the
bridge and presents a much higher average current through those diodes.
Since heating effect is, as I'm sure you are aware[1], proportional to
i^2 premature failures of the diodes can be expected unless the diodes
are over-specced to deal with this situation.

In my experience heating effect has always been V x I. It so happens
that the voltage appearing across the specific case of a resistor is
proportional to current to give a heating effect proportional to I^2.
However, diodes do not behave in the same linear way as resistors.

On 09/07/2011 18:30, Gordon Henderson wrote:
In articleca2dnVwirYNpw4rTnZ2dnUVZ7q6dnZ2d@brightvie w.co.uk,
Andy wrote:

The BBC Micro had an SMPSU, Way back when, I knew someone who soldered
100 NiCads in series (housed in a length of drainpipe) with a 13A socket
on one end, it happily powered the BBC micro ... OK so it's not a modern
laptop.

That seemed like hard work... Once upon a time, I used a BBC B to 'drive'
an experimental Automatic Guided Vehicle round a factory floor. The AGV
had a pair of 12V lead acid batterys and I just wired the 12V from the
battery into a 5V regulator and used that to power the unit. I think it
needed -5V for something, but I've forgotten what now but it seemed OK
without it! I'd have the AGV next to my workbench, plug the Beeb into a
monitor& the Econet, load up the software, then unplug it, sit on the
AGV and drive it round using the F keys for speed and arrows to steer
(ok, not quite automatic, but it was proof of concept

Gordon

I thought the 6502 was a NMOS CPU which required a -5V supply? It would
have taken very little current, would it have been sourced by a charge
pump of the +5V?

On Mon, 11 Jul 2011 00:38:20 +0100, Steve Firth wrote:

330v dc.

You mean a peak of 339.41V, the average being 216.08V.

Where does the 216.08v come from? How can you have two decimal
places of precision for something connected to the mains that has a
+6 -10% allowable tolerance on the voltage?

The voltage across the smoothing capacitor(s) after the full wave
bridge rectifier could be anywhere from 300 to 354v DC with a nominal
value of 322v DC. Ripple will subtract from the DC voltage when on
load.

--
Cheers
Dave.

In article ,
"David WE Roberts" writes:

All I really need is something to recharge the batteries without having to
run the engine.

Not that I've looked, but I would have thought someone would make
a frame consisting of a petrol engine and an alternator, specifically
for this sort of task. Something like an older Lucus alternator (with
embedded controller, rather than a modern one controlled by the engine
management unit) would probably work well. Even on my decades old mini,
that could output 45A peak (and 32A on tickover), and there were
probably larger ones for larger cars. It contains all the smarts for
charging regulation, and doesn't care about clean power input (which is
mechanicanal in this case anyway).

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.

They have inverter outputs, designed to generate just a very slightly
fractionally higher voltage than mains, so they feed back into it
the rate they're generating. You can't use them without having a
working mains supply - they're deliberately designed to switch-off
if the mains goes away. Apart from having no voltage to regulate
against, you don't want something back-feeding a dead supply network
and electrocuting someone who might be working on it.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Jul 8, 1:00*pm, NT wrote:
On Jul 8, 11:40*am, Fredxx wrote:



On 08/07/2011 09:06, NT wrote:

On Jul 7, 10:14 pm, *wrote:
On 07/07/2011 20:52, NT wrote:

On Jul 7, 8:44 pm, "David WE Roberts"
* *wrote:
snip snip

Aldi have an 800w (peak) 650w standard generator up for 59.99 this Sunday.

I am considering this as an emergency power supply to the motorhome when
wild camping.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for just
under 180 which does compare favourably with 400 for a 2Kw generator from
Kipor.

All I really need is something to recharge the batteries without having to
run the engine.
So with 2 * 100 amp hour batteries to charge from 50% to 100% I would need
100 amps for an hour - well, lets say 50 amps for 2 hours.
Amps = watts/volts so
300 watts at 12 volts should give 25 amps charge current - 4 hours running.
600 watts at 12 volts should give 50 amps charge current (if the system
would take it) - 2 hours running.

All in all, a 600w generator run for a couple of hours in the morning should
be a reasonable alternative to a solar panel on the roof, given that 100w of
solar panel can cost 300 without the controller or fixing kit.

So , what does the team think?

Cheers

Dave R

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.

If your chagrer is electronic swtched mode, just full wave rectify the
output from each gen, then conncet all 3 together. Check the genny
chassis is NOT connected to either L or N before doing this - it
probabyl wont be.

Wouldn't it be cheaper and less hassle "just" to get a bigger genny?

Another option I looked at for much teh same task was to build a big
nonrechargeable battery.

Why? *If cost is an issue, how can that be cost effective?

A big battery costs peanuts compared to a generator. There's a wide
variety of chemistries available, IIRC the one that tempted me was
aluminium electrodes in what was it, soda? I dont remember the
electrolyte now.

NT

Aluminium is 2.50 per kg at world prices, in practice you'll be paying
double this.

A Aluminium KOH batter gets 1300WH per kg. *Hand waving guess.

So 2 per kWH

We also have to factor in that Al batteries degrade irrespective of
whether a current is drawn or not.

You can get a 850W genny from Machine Mart for just 100, ie just 40kg
of aluminium at world prices.

I don't feel quite as "tempted" as you!!

Aluminium costs nothing in the form of drinks cans, just look in the
recycling box. There is no degradation when no current is drawn, the
plates are kept dry, only dipped in when power is wanted. If you dont
like the ali cells there are plenty of other options.

NT

FWIW one way to make these charge lead acids is to make only 2 cells,
eg in ice cream tubs, or really something more robust but similar
size, run a meaty 6v relay in self oscillating mode, and use a good
sized transformer with its priamry removed as a choke. Between that
lot you get a slow switched mode upconvertor with minimal hassle. The
2 cells are stored in unfilled form: the water and soda (or whatever
youre using) are stored in a separate containers.

The advantages of a switche mode convertor are simplicity of battery
construction, and simplicity of plate replacement. The electrical
output of one with no lead acid connected is lethal.

You can run one off a single cell in principle, but you'd then need to
rewind both relay and transformer, and every circuit connection
becomes resistance critical. There are several variations on the
theme, 2 cells and no primary on the transformer are probably the
simplest.


NT

On 12/07/2011 10:47, NT wrote:
On Jul 8, 1:00 pm, wrote:
On Jul 8, 11:40 am, wrote:



On 08/07/2011 09:06, NT wrote:

On Jul 7, 10:14 pm, wrote:
On 07/07/2011 20:52, NT wrote:

On Jul 7, 8:44 pm, "David WE Roberts"
wrote:
snip snip

Aldi have an 800w (peak) 650w standard generator up for 59.99 this Sunday.

I am considering this as an emergency power supply to the motorhome when
wild camping.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for just
under 180 which does compare favourably with 400 for a 2Kw generator from
Kipor.

All I really need is something to recharge the batteries without having to
run the engine.
So with 2 * 100 amp hour batteries to charge from 50% to 100% I would need
100 amps for an hour - well, lets say 50 amps for 2 hours.
Amps = watts/volts so
300 watts at 12 volts should give 25 amps charge current - 4 hours running.
600 watts at 12 volts should give 50 amps charge current (if the system
would take it) - 2 hours running.

All in all, a 600w generator run for a couple of hours in the morning should
be a reasonable alternative to a solar panel on the roof, given that 100w of
solar panel can cost 300 without the controller or fixing kit.

So , what does the team think?

Cheers

Dave R

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.

If your chagrer is electronic swtched mode, just full wave rectify the
output from each gen, then conncet all 3 together. Check the genny
chassis is NOT connected to either L or N before doing this - it
probabyl wont be.

Wouldn't it be cheaper and less hassle "just" to get a bigger genny?

Another option I looked at for much teh same task was to build a big
nonrechargeable battery.

Why? If cost is an issue, how can that be cost effective?

A big battery costs peanuts compared to a generator. There's a wide
variety of chemistries available, IIRC the one that tempted me was
aluminium electrodes in what was it, soda? I dont remember the
electrolyte now.

NT

Aluminium is 2.50 per kg at world prices, in practice you'll be paying
double this.

A Aluminium KOH batter gets 1300WH per kg. Hand waving guess.

So 2 per kWH

We also have to factor in that Al batteries degrade irrespective of
whether a current is drawn or not.

You can get a 850W genny from Machine Mart for just 100, ie just 40kg
of aluminium at world prices.

I don't feel quite as "tempted" as you!!

Aluminium costs nothing in the form of drinks cans, just look in the
recycling box. There is no degradation when no current is drawn, the
plates are kept dry, only dipped in when power is wanted. If you dont
like the ali cells there are plenty of other options.

NT

FWIW one way to make these charge lead acids is to make only 2 cells,
eg in ice cream tubs, or really something more robust but similar
size, run a meaty 6v relay in self oscillating mode, and use a good
sized transformer with its priamry removed as a choke. Between that
lot you get a slow switched mode upconvertor with minimal hassle. The
2 cells are stored in unfilled form: the water and soda (or whatever
youre using) are stored in a separate containers.

The advantages of a switche mode convertor are simplicity of battery
construction, and simplicity of plate replacement. The electrical
output of one with no lead acid connected is lethal.

You can run one off a single cell in principle, but you'd then need to
rewind both relay and transformer, and every circuit connection
becomes resistance critical. There are several variations on the
theme, 2 cells and no primary on the transformer are probably the
simplest.



Have you built one of these? Surely a standard switching boost
regulator would be far better than a relay!!

On Jul 12, 11:16*am, Fredxx wrote:
On 12/07/2011 10:47, NT wrote:



On Jul 8, 1:00 pm, *wrote:
On Jul 8, 11:40 am, *wrote:

On 08/07/2011 09:06, NT wrote:

On Jul 7, 10:14 pm, * *wrote:
On 07/07/2011 20:52, NT wrote:

On Jul 7, 8:44 pm, "David WE Roberts"
* * *wrote:
snip snip

Aldi have an 800w (peak) 650w standard generator up for 59.99 this Sunday.

I am considering this as an emergency power supply to the motorhome when
wild camping.

Hmmm.......any way of linking the output of 3 of these together?
That would give 2.4kw (peak) 1.95kw (standard) of generating power for just
under 180 which does compare favourably with 400 for a 2Kw generator from
Kipor.

All I really need is something to recharge the batteries without having to
run the engine.
So with 2 * 100 amp hour batteries to charge from 50% to 100% I would need
100 amps for an hour - well, lets say 50 amps for 2 hours.
Amps = watts/volts so
300 watts at 12 volts should give 25 amps charge current - 4 hours running.
600 watts at 12 volts should give 50 amps charge current (if the system
would take it) - 2 hours running.

All in all, a 600w generator run for a couple of hours in the morning should
be a reasonable alternative to a solar panel on the roof, given that 100w of
solar panel can cost 300 without the controller or fixing kit.

So , what does the team think?

Cheers

Dave R

P.S. there must be a reasonably simple way of combining different 240V
inputs or the whole concept of solar feed in just wouldn't work.

If your chagrer is electronic swtched mode, just full wave rectify the
output from each gen, then conncet all 3 together. Check the genny
chassis is NOT connected to either L or N before doing this - it
probabyl wont be.

Wouldn't it be cheaper and less hassle "just" to get a bigger genny?

Another option I looked at for much teh same task was to build a big
nonrechargeable battery.

Why? *If cost is an issue, how can that be cost effective?

A big battery costs peanuts compared to a generator. There's a wide
variety of chemistries available, IIRC the one that tempted me was
aluminium electrodes in what was it, soda? I dont remember the
electrolyte now.

NT

Aluminium is 2.50 per kg at world prices, in practice you'll be paying
double this.

A Aluminium KOH batter gets 1300WH per kg. *Hand waving guess.

So 2 per kWH

We also have to factor in that Al batteries degrade irrespective of
whether a current is drawn or not.

You can get a 850W genny from Machine Mart for just 100, ie just 40kg
of aluminium at world prices.

I don't feel quite as "tempted" as you!!

Aluminium costs nothing in the form of drinks cans, just look in the
recycling box. There is no degradation when no current is drawn, the
plates are kept dry, only dipped in when power is wanted. If you dont
like the ali cells there are plenty of other options.

NT

FWIW one way to make these charge lead acids is to make only 2 cells,
eg in ice cream tubs, or really something more robust but similar
size, run a meaty 6v relay in self oscillating mode, and use a good
sized transformer with its priamry removed as a choke. Between that
lot you get a slow switched mode upconvertor with minimal hassle. The
2 cells are stored in unfilled form: the water and soda (or whatever
youre using) are stored in a separate containers.

The advantages of a switche mode convertor are simplicity of battery
construction, and simplicity of plate replacement. The electrical
output of one with no lead acid connected is lethal.

You can run one off a single cell in principle, but you'd then need to
rewind both relay and transformer, and every circuit connection
becomes resistance critical. There are several variations on the
theme, 2 cells and no primary on the transformer are probably the
simplest.

Have you built one of these? *Surely a standard switching boost
regulator would be far better than a relay!!

Electronic ones are more energy efficient and silent, but how many
diyers could make one? Relay based switched mode convertors are
extremely simple. I did forget to mention add snubbers on the relay.


NT