On Sat, 8 Dec 2018 17:55:55 -0600, dpb wrote:

On 12/8/2018 1:26 PM, Clare Snyder wrote:
...

They USED to have "wild pilots" too - where the gas flowed to the
pilot even if the pilot light blew out.
Nasty things, those wild pilots.

The little heater in the well house was one for over 50 years until I
swapped it out for a safety valve setup a couple years ago....the amount
of gas through the pilot is so small as to be essentially negligible
unless the area is extremely small and very tight...in the 10x16x8 well
house, it was difficult to smell the odor even if it had been a day or
more before discovered it was out.

But, the gas co guy during one leak check visit said he didn't dare let
it go any longer as "by the book" he could be as much as fired if
another tech came by after him and noted it and he hadn't...

Not that it isn't better to have than not, but they really aren't _that_
risky.
Not in a drafty well-house. Not with natural gas. But propane in the
well house, or natural gas in an unvented area could be a "big bang"
not only in theory- - - - - -

On 12/8/2018 8:21 PM, Clare Snyder wrote:
On Sat, 8 Dec 2018 17:55:55 -0600, dpb wrote:

On 12/8/2018 1:26 PM, Clare Snyder wrote:
...

They USED to have "wild pilots" too - where the gas flowed to the
pilot even if the pilot light blew out.
Nasty things, those wild pilots.

The little heater in the well house was one for over 50 years until I
swapped it out for a safety valve setup a couple years ago....the amount
of gas through the pilot is so small as to be essentially negligible
unless the area is extremely small and very tight...in the 10x16x8 well
house, it was difficult to smell the odor even if it had been a day or
more before discovered it was out.

But, the gas co guy during one leak check visit said he didn't dare let
it go any longer as "by the book" he could be as much as fired if
another tech came by after him and noted it and he hadn't...

Not that it isn't better to have than not, but they really aren't _that_
risky.
Not in a drafty well-house. Not with natural gas. But propane in the
well house, or natural gas in an unvented area could be a "big bang"
not only in theory- - - - - -

It's _not_ "a drafty well house"...it's a well-built, insulated block
building...heavier than air propane is potentially a different animal, yes.

--

"Bruce Farquhar" wrote:
On older boilers (furnaces if you're American), when the heating isn't
actually running (eg. the thermostat says the house is warm enough),
there's no power to the boiler, so how does the pilot light valve stay
open with the tiny voltage (40mV?) and current from the thermocouple?

What are they using, real boiler steam heat, or hot water ?

On Sun, 9 Dec 2018 08:19:13 -0000 (UTC), gregz, the unbelievably stupid,
troll-feeding senile idiot, blathered:

What are they using, real boiler steam heat, or hot water ?

He's using YOU for his trolling, you unbelievably stupid, senile idiot!
tsk

On Sun, 09 Dec 2018 02:18:42 -0000, Clare Snyder wrote:

On Sat, 8 Dec 2018 22:59:22 -0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Clive Arthur writes:
On 08/12/2018 17:51, Bruce Farquhar wrote:
On Sat, 08 Dec 2018 17:40:57 -0000, wrote:

On 12/8/18 11:41 AM, Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating isn't
actually running (eg. the thermostat says the house is warm enough),
there's no power to the boiler, so how does the pilot light valve stay
open with the tiny voltage (40mV?) and current from the thermocouple?

To *hold* the valve open only requires a small voltage & current. To
*pull* the valve open would require a larger voltage. That's why you
have to "Press & Hold" the manual knob to restart a pilot.

See here for more detail:
https://en.wikipedia.org/wiki/Thermo...pliance_safety

I see, thanks. I thought the "press and hold" was just to keep the
valve open until the thermocouple warmed up. So I'm providing the
effort to open the valve with my thumb. That link states 0.2-0.25A - do
you really get that much current off a thermocouple?

Yes, it's a very low impedance source, a metal to different metal
contact. 10mV 200mA is 50 milliohms. It's only 2mW, but that's a very
small proportion of the pilot flame power.

Indeed - a pilot flame is typically around 250W.

A lot closer to 65 than 250 for MOST natural gas pilot lights (about
60 cu meters per year) Some of the really old ones may have used 4
times as much - - -
Nothing available today (in a furnace) (at least in Canada) has a
standing pilot. All have electric ignition as part of the "high
efficiency"standard.

I doubt it's as high as either of those, or your gas bill would be astronomical. Plus the boiler would feel pretty damn warm to the touch even when not using the main burner. Imagine leaving a 60W lightbulb running inside a metal box and think how hot it would get.

On Sun, 09 Dec 2018 08:19:13 -0000, gregz wrote:

"Bruce Farquhar" wrote:
On older boilers (furnaces if you're American), when the heating isn't
actually running (eg. the thermostat says the house is warm enough),
there's no power to the boiler, so how does the pilot light valve stay
open with the tiny voltage (40mV?) and current from the thermocouple?

What are they using, real boiler steam heat, or hot water ?

In the UK we use hot water, about 70 to 80C. This heats (by a heat exchanger) the hot water tank, and directly the radiators full of water. Or more modern ones heat the water for hot taps directly, but those are new enough to not use pilot lights, they have electric spark ignition.

On Sat, 08 Dec 2018 23:07:39 -0000, Rod Speed wrote:



wrote in message
...
On 12/8/18 3:36 PM, Rod Speed wrote:


wrote in message
...
On 12/8/18 1:39 PM, Davey wrote:
On Sat, 08 Dec 2018 16:41:17 -0000
"Bruce Farquhar" wrote:

On older boilers (furnaces if you're American), when the heating
isn't actually running (eg. the thermostat says the house is warm
enough), there's no power to the boiler, so how does the pilot light
valve stay open with the tiny voltage (40mV?) and current from the
thermocouple?

When I lived in America, I was confused that what Honeywell called a
Thermocouple was actually a bulb and capillary tube.

See:
https://www.amazon.co.uk/Honeywell-Q.../dp/B01H2SOZSK

They do not use the differential metal concept, but rather pressure due
to expanding liquid.



Sorry, not so.

Just because it looks like a bulb and capillary, it's not.

See
https://customer.honeywell.com/en-US...uct.Rank&asc=1


Server Error in '/' Application

Oh well. Clicking on link works OK here. Thunderbird & Firefox on Mac OS X

Does now too, must have just been a short term glitch on the server or
something.

Agreed, no problems here yesterday or today on Opera in Windows 10.

A thermocouple produces enough to power a spacecraft?!? Or just for some small electronics?


On Sat, 08 Dec 2018 21:04:59 -0000, Brian Gaff wrote:

I'm sure you know this but the Voyager spacecraft are using thermocouples
using the heat from decaying plutonium for power all the way out in the
cosmos. it may be reducing now but its been one heck of a long time.
Brian

On Sat, 08 Dec 2018 20:33:27 -0000, Rod Speed wrote:



"Bruce Farquhar" wrote in message
news
On Sat, 08 Dec 2018 18:32:08 -0000, Max Demian
wrote:

On 08/12/2018 16:41, Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating isn't
actually running (eg. the thermostat says the house is warm enough),
there's no power to the boiler, so how does the pilot light valve stay
open with the tiny voltage (40mV?) and current from the thermocouple?

Well they used to have a bimetallic strip to hold the pilot light valve
open rather than a thermocouple. Or maybe that's when boilers didn't
have an electrical connection at all.

The electricity from the mains supply (on an old basic/system
boiler/furnace) is nothing to do with the pilot light, it just operates
the main gas valve. The mains connection to my boiler is only on when the
room stat calls for heat. When the room is warm enough, no electricity is
given to the boiler at all.

What do you mean "when boilers didn't have an electrical connection at
all"? Surely they need something to tell them to start burning gas?

Doesn't have to be an electrical thermostat, can be
a bimetallic thermostat or a bulb and capillary tube.

For the internal stat for its own tank, yes. But the room stat needs to tell the boiler remotely, which is always electricity surely.

On Sat, 08 Dec 2018 19:53:35 -0000, Mr Pounder Esquire wrote:

Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating
isn't actually running (eg. the thermostat says the house is warm
enough), there's no power to the boiler, so how does the pilot light
valve stay open with the tiny voltage (40mV?) and current from the
thermocouple?

**** off and die Hucker.

Get a hobby or contribute something to the group, ******.

On Sat, 08 Dec 2018 19:49:40 -0000, wrote:

On 12/8/18 2:24 PM, Clare Snyder wrote:
On Sat, 8 Dec 2018 12:40:57 -0500, wrote:

On 12/8/18 11:41 AM, Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating isn't
actually running (eg. the thermostat says the house is warm enough),
there's no power to the boiler, so how does the pilot light valve stay
open with the tiny voltage (40mV?) and current from the thermocouple?

To *hold* the valve open only requires a small voltage & current. To
*pull* the valve open would require a larger voltage. That's why you
have to "Press & Hold" the manual knob to restart a pilot.

See here for more detail:
https://en.wikipedia.org/wiki/Thermo...pliance_safety
Don't know about the UK, but MOST north American furnaces don't use
the thermocouple voltage to operate the valve. The thermocouple
"signal" uperates an electronic circuit that provides power from a
transformer to operate the gas valve for the furnace burner - the
thermocouple DOES operate the "hold" bias forthe(very small and low
powered) pilot valve.

Some gas fireplaces and non fan forced heaters use a
"thermopile" that does operate the actual gasvalve directly - allowing
use without grid power.


I was using the word valve to mean the pilot light's own valve that
closes if the pilot goes out, as used in the Wiki article.

BTW I've seen main line gas valves that have a lever to open them in
event of AC power failure. Although not much help on forced air furnaces.

Not much point in doing that with my system, as the pump to move the water to the radiators needs electricity. I assume forced air systems need electricity for the fans.

Of course if I had regular powercuts, I could simply use a battery backup with an invertor (like a computer UPS) to make it run.

On Sunday, December 9, 2018 at 11:36:53 AM UTC-5, Bruce Farquhar wrote:
On Sun, 09 Dec 2018 02:18:42 -0000, Clare Snyder wrote:

On Sat, 8 Dec 2018 22:59:22 -0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Clive Arthur writes:
On 08/12/2018 17:51, Bruce Farquhar wrote:
On Sat, 08 Dec 2018 17:40:57 -0000, wrote:

On 12/8/18 11:41 AM, Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating isn't
actually running (eg. the thermostat says the house is warm enough),
there's no power to the boiler, so how does the pilot light valve stay
open with the tiny voltage (40mV?) and current from the thermocouple?

To *hold* the valve open only requires a small voltage & current. To
*pull* the valve open would require a larger voltage. That's why you
have to "Press & Hold" the manual knob to restart a pilot.

See here for more detail:
https://en.wikipedia.org/wiki/Thermo...pliance_safety

I see, thanks. I thought the "press and hold" was just to keep the
valve open until the thermocouple warmed up. So I'm providing the
effort to open the valve with my thumb. That link states 0.2-0.25A - do
you really get that much current off a thermocouple?

Yes, it's a very low impedance source, a metal to different metal
contact. 10mV 200mA is 50 milliohms. It's only 2mW, but that's a very
small proportion of the pilot flame power.

Indeed - a pilot flame is typically around 250W.

A lot closer to 65 than 250 for MOST natural gas pilot lights (about
60 cu meters per year) Some of the really old ones may have used 4
times as much - - -
Nothing available today (in a furnace) (at least in Canada) has a
standing pilot. All have electric ignition as part of the "high
efficiency"standard.

I doubt it's as high as either of those, or your gas bill would be astronomical. Plus the boiler would feel pretty damn warm to the touch even when not using the main burner. Imagine leaving a 60W lightbulb running inside a metal box and think how hot it would get.

I could run a 60W bulb 24/7 for a month here for $5 using electric.
Natural gas is about half the cost of electric or less, so figure ~$2
a month for a 60W pilot light. That's not astronomical nor would
60W going into a boiler produce much in the way of raising it's temp
significantly. Most of that small amount of heat probably goes right
up the flue with the natural draft that's there, unless it's a modern
one that limits that. But those don't have pilot lights.

On 09/12/2018 16:40, Bruce Farquhar wrote:
A thermocouple produces enough to power a spacecraft?!?* Or just for
some small electronics?

They can generate up to a few hundred watts, enough for the electronics,
instruments and transmitter:

https://en.wikipedia.org/wiki/Radioi...tric_generator

--
Max Demian

On Sun, 9 Dec 2018 09:16:12 -0800 (PST), tardo_4 an especially stupid,
troll-feeding, senile idiot, blathered:


I could run

You can run as a brain dead, notorious, senile sucker of troll cock,
tardo_4, you senile piece of Yankie ****!

On Sun, 9 Dec 2018 18:29:19 +0000, Max Demian, an especially stupid,
notorious, troll-feeding, senile idiot, blathered



They can generate up to a few hundred watts, enough for the electronics,
instruments and transmitter:

https://en.wikipedia.org/wiki/Radioi...tric_generator

Is there NO troll bait silly enough that you brain-dead, troll-feeding,
senile idiot will NOT take? tsk

On 12/9/2018 12:29 PM, Max Demian wrote:
On 09/12/2018 16:40, Bruce Farquhar wrote:
A thermocouple produces enough to power a spacecraft?!?* Or just for
some small electronics?

They can generate up to a few hundred watts, ...

They _can_ generate as much as you have space and weight to be able to
package...

For extra-terrestrial use, the payload limits are the issue.


--

On Sun, 9 Dec 2018 18:29:19 +0000, Max Demian
wrote:

On 09/12/2018 16:40, Bruce Farquhar wrote:
A thermocouple produces enough to power a spacecraft?!?* Or just for
some small electronics?

They can generate up to a few hundred watts, enough for the electronics,
instruments and transmitter:

https://en.wikipedia.org/wiki/Radioi...tric_generator
There is a big difference between a "thermocouple" and a "peltier
junction device". Most "thermoelectic generators" are Peltier.

Bruce Farquhar wrote

A thermocouple produces enough to power a spacecraft?!?

It isnt a single thermocouple, it's a thermopile.
https://en.wikipedia.org/wiki/Thermopile
https://en.wikipedia.org/wiki/Nuclear_power_in_space

Or just for some small electronics?

Not small at all.

On Sat, 08 Dec 2018 21:04:59 -0000, Brian Gaff
wrote:

I'm sure you know this but the Voyager spacecraft are using thermocouples
using the heat from decaying plutonium for power all the way out in the
cosmos. it may be reducing now but its been one heck of a long time.

"Bruce Farquhar" wrote in message
news
On Sat, 08 Dec 2018 20:33:27 -0000, Rod Speed
wrote:



"Bruce Farquhar" wrote in message
news
On Sat, 08 Dec 2018 18:32:08 -0000, Max Demian
wrote:

On 08/12/2018 16:41, Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating isn't
actually running (eg. the thermostat says the house is warm enough),
there's no power to the boiler, so how does the pilot light valve stay
open with the tiny voltage (40mV?) and current from the thermocouple?

Well they used to have a bimetallic strip to hold the pilot light valve
open rather than a thermocouple. Or maybe that's when boilers didn't
have an electrical connection at all.

The electricity from the mains supply (on an old basic/system
boiler/furnace) is nothing to do with the pilot light, it just operates
the main gas valve. The mains connection to my boiler is only on when
the
room stat calls for heat. When the room is warm enough, no electricity
is
given to the boiler at all.

What do you mean "when boilers didn't have an electrical connection at
all"? Surely they need something to tell them to start burning gas?

Doesn't have to be an electrical thermostat, can be
a bimetallic thermostat or a bulb and capillary tube.

For the internal stat for its own tank, yes. But the room stat needs to
tell the boiler remotely, which is always electricity surely.

No, the original oil or gas fired boilers didn't have to be.
Corse they werent always thermostatted either.

"Bruce Farquhar" wrote in message
news
On Sat, 08 Dec 2018 19:53:35 -0000, Mr Pounder Esquire
wrote:

Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating
isn't actually running (eg. the thermostat says the house is warm
enough), there's no power to the boiler, so how does the pilot light
valve stay open with the tiny voltage (40mV?) and current from the
thermocouple?

**** off and die Hucker.

Get a hobby or contribute something to the group, ******.

He already does both. But all it contributes in that sort of ****.

On Mon, 10 Dec 2018 08:40:03 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:


Or just for some small electronics?

Not small at all.

You STILL haven't learned your lesson, my favourite senile punching bag?
OK, wait and see... LOL

--
about senile Rot Speed:
"This is like having a conversation with someone with brain damage."
MID:

On Mon, 10 Dec 2018 08:42:36 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:


No

Still competing with the Scottish ****** for the position as top idiot on
all these groups, senile Rot? LOL

--
dennis@home to know-it-all Rot Speed:
"You really should stop commenting on things you know nothing about."
Message-ID:

On Mon, 10 Dec 2018 08:44:11 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:


Get a hobby or contribute something to the group, ******.

He already does both. But all it contributes in that sort of ****.

The Scottish ******'s hobby is getting you to suck him off as often as
possible; and your senile hobby is to suck him off as often as possible,
right, senile Rot? Now try to disprove it, senile cocksucker! BG

--
Norman Wells addressing senile Rot:
"Ah, the voice of scum speaks."
MID:

On Sun, 09 Dec 2018 21:44:11 -0000, Rod Speed wrote:



"Bruce Farquhar" wrote in message
news
On Sat, 08 Dec 2018 19:53:35 -0000, Mr Pounder Esquire
wrote:

Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating
isn't actually running (eg. the thermostat says the house is warm
enough), there's no power to the boiler, so how does the pilot light
valve stay open with the tiny voltage (40mV?) and current from the
thermocouple?

**** off and die Hucker.

Get a hobby or contribute something to the group, ******.

He already does both. But all it contributes in that sort of ****.

Pounder has no hobbies. He just does as his wife tells him.

On Sun, 09 Dec 2018 21:42:36 -0000, Rod Speed wrote:



"Bruce Farquhar" wrote in message
news
On Sat, 08 Dec 2018 20:33:27 -0000, Rod Speed
wrote:



"Bruce Farquhar" wrote in message
news On Sat, 08 Dec 2018 18:32:08 -0000, Max Demian
wrote:

On 08/12/2018 16:41, Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating isn't
actually running (eg. the thermostat says the house is warm enough),
there's no power to the boiler, so how does the pilot light valve stay
open with the tiny voltage (40mV?) and current from the thermocouple?

Well they used to have a bimetallic strip to hold the pilot light valve
open rather than a thermocouple. Or maybe that's when boilers didn't
have an electrical connection at all.

The electricity from the mains supply (on an old basic/system
boiler/furnace) is nothing to do with the pilot light, it just operates
the main gas valve. The mains connection to my boiler is only on when
the
room stat calls for heat. When the room is warm enough, no electricity
is
given to the boiler at all.

What do you mean "when boilers didn't have an electrical connection at
all"? Surely they need something to tell them to start burning gas?

Doesn't have to be an electrical thermostat, can be
a bimetallic thermostat or a bulb and capillary tube.

For the internal stat for its own tank, yes. But the room stat needs to
tell the boiler remotely, which is always electricity surely.

No, the original oil or gas fired boilers didn't have to be.
Corse they werent always thermostatted either.

If they had a room stat, how else would the stat tell the boiler to fire up?

On Sun, 09 Dec 2018 21:40:03 -0000, Rod Speed wrote:

Bruce Farquhar wrote

A thermocouple produces enough to power a spacecraft?!?

It isnt a single thermocouple, it's a thermopile.
https://en.wikipedia.org/wiki/Thermopile
https://en.wikipedia.org/wiki/Nuclear_power_in_space

Or just for some small electronics?

Not small at all.

Why are these not used on earth?

On Sat, 08 Dec 2018 21:04:59 -0000, Brian Gaff
wrote:

I'm sure you know this but the Voyager spacecraft are using thermocouples
using the heat from decaying plutonium for power all the way out in the
cosmos. it may be reducing now but its been one heck of a long time.

In "Bruce Farquhar" writes:

Why are these not used on earth?

Do you really, really, want chunks of plutonium
or strontium 90i sitting around?

Well, since you ask:

[wiki]

In addition to spacecraft, the Soviet Union constructed
many unmanned lighthouses and navigation beacons
powered by RTGs.[5]
......
One RTG, the SNAP-19C, was lost near the top of Nanda
Devi mountain in India in 1965 when it was stored
in a rock formation near the top of the mountain
in the face of a snowstorm before it could be
installed to power a CIA remote automated station
collecting telemetry from the Chinese rocket testing facility.
=======
rest:
https://en.wikipedia.org/wiki/Radioi...tric_generator
On Sat, 08 Dec 2018 21:04:59 -0000, Brian Gaff
wrote:

I'm sure you know this but the Voyager spacecraft are using thermocouples
using the heat from decaying plutonium for power all the way out in the
cosmos. it may be reducing now but its been one heck of a long time.

--
__________________________________________________ ___
Knowledge may be power, but communications is the key

[to foil spammers, my address has been double rot-13 encoded]

On 12/9/2018 5:07 PM, Bruce Farquhar wrote:
On Sun, 09 Dec 2018 21:40:03 -0000, Rod Speed
wrote:

Bruce Farquhar wrote

A thermocouple produces enough to power a spacecraft?!?

It isnt a single thermocouple, it's a thermopile.
https://en.wikipedia.org/wiki/Thermopile
https://en.wikipedia.org/wiki/Nuclear_power_in_space

Or just for some small electronics?

Not small at all.

Why are these not used on earth?
....

They are...and have been for 40 yr or more in remote locations like the
Arctic, Antarctic, lighthouses, etc., etc., ... the Russians probably
have had the most numerically but they've no monopoly.

--

On Sun, 09 Dec 2018 23:28:59 -0000, danny burstein wrote:

In "Bruce Farquhar" writes:

Why are these not used on earth?

Do you really, really, want chunks of plutonium
or strontium 90i sitting around?

We do have nuclear power stations which can and do explode....

Well, since you ask:

[wiki]

In addition to spacecraft, the Soviet Union constructed
many unmanned lighthouses and navigation beacons
powered by RTGs.[5]
......
One RTG, the SNAP-19C, was lost near the top of Nanda
Devi mountain in India in 1965 when it was stored
in a rock formation near the top of the mountain
in the face of a snowstorm before it could be
installed to power a CIA remote automated station
collecting telemetry from the Chinese rocket testing facility.
=======
rest:
https://en.wikipedia.org/wiki/Radioi...tric_generator
On Sat, 08 Dec 2018 21:04:59 -0000, Brian Gaff
wrote:

I'm sure you know this but the Voyager spacecraft are using thermocouples
using the heat from decaying plutonium for power all the way out in the
cosmos. it may be reducing now but its been one heck of a long time.

On Sun, 9 Dec 2018 17:41:59 -0600, dpb, yet another braindamaged,
troll-feeding, senile Yankietard, blathered:


They are...and have

Unbelievable! The filthy Scottish ******, attention whore and troll asks
....and some senile Yank like you will inevitably run along to start feeding
him! LOL

"Bruce Farquhar" wrote in message
news
On Sun, 09 Dec 2018 21:44:11 -0000, Rod Speed
wrote:



"Bruce Farquhar" wrote in message
news
On Sat, 08 Dec 2018 19:53:35 -0000, Mr Pounder Esquire
wrote:

Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating
isn't actually running (eg. the thermostat says the house is warm
enough), there's no power to the boiler, so how does the pilot light
valve stay open with the tiny voltage (40mV?) and current from the
thermocouple?

**** off and die Hucker.

Get a hobby or contribute something to the group, ******.

He already does both. But all it contributes is that sort of ****.

Pounder has no hobbies.

Corse he does, post that steaming turd to all your posts.

He just does as his wife tells him.

And does that your posts. Unlikely his wife tells him to do that.

"Bruce Farquhar" wrote in message
news
On Sun, 09 Dec 2018 21:42:36 -0000, Rod Speed
wrote:



"Bruce Farquhar" wrote in message
news
On Sat, 08 Dec 2018 20:33:27 -0000, Rod Speed
wrote:



"Bruce Farquhar" wrote in message
news On Sat, 08 Dec 2018 18:32:08 -0000, Max Demian

wrote:

On 08/12/2018 16:41, Bruce Farquhar wrote:
On older boilers (furnaces if you're American), when the heating
isn't
actually running (eg. the thermostat says the house is warm enough),
there's no power to the boiler, so how does the pilot light valve
stay
open with the tiny voltage (40mV?) and current from the
thermocouple?

Well they used to have a bimetallic strip to hold the pilot light
valve
open rather than a thermocouple. Or maybe that's when boilers didn't
have an electrical connection at all.

The electricity from the mains supply (on an old basic/system
boiler/furnace) is nothing to do with the pilot light, it just
operates
the main gas valve. The mains connection to my boiler is only on when
the
room stat calls for heat. When the room is warm enough, no
electricity
is
given to the boiler at all.

What do you mean "when boilers didn't have an electrical connection at
all"? Surely they need something to tell them to start burning gas?

Doesn't have to be an electrical thermostat, can be
a bimetallic thermostat or a bulb and capillary tube.

For the internal stat for its own tank, yes. But the room stat needs to
tell the boiler remotely, which is always electricity surely.

No, the original oil or gas fired boilers didn't have to be.
Corse they werent always thermostatted either.

If they had a room stat, how else would the stat tell the boiler to fire
up?

Doesn't have to be an electrical stat tho.

"Bruce Farquhar" wrote in message
news
On Sun, 09 Dec 2018 21:40:03 -0000, Rod Speed
wrote:

Bruce Farquhar wrote

A thermocouple produces enough to power a spacecraft?!?

It isnt a single thermocouple, it's a thermopile.
https://en.wikipedia.org/wiki/Thermopile
https://en.wikipedia.org/wiki/Nuclear_power_in_space

Or just for some small electronics?

Not small at all.

Why are these not used on earth?

A few were, mostly by the russians for powering remote places like
lighthouses.

Its more viable to use a solar panel and batterys for most situations
on earth. The long range probes don't always have enough sunlight
to go that route with probes so use small nukes instead. Very reliable,
no moving parts to fail.

On Sat, 08 Dec 2018 21:04:59 -0000, Brian Gaff

wrote:

I'm sure you know this but the Voyager spacecraft are using
thermocouples
using the heat from decaying plutonium for power all the way out in the
cosmos. it may be reducing now but its been one heck of a long time.

"Bruce Farquhar" wrote in message
news
On Sun, 09 Dec 2018 23:28:59 -0000, danny burstein
wrote:

In "Bruce Farquhar"
writes:

Why are these not used on earth?

Do you really, really, want chunks of plutonium
or strontium 90i sitting around?

We do have nuclear power stations which can and do explode....

Those ones used on earth don't.

And even you should have noticed that with an unmanned
light house or warning light on the top of a mountain etc
that it's not that easy to stop someone grabbing it and
taking it home to power their remote holiday shack etc.

Well, since you ask:

[wiki]

In addition to spacecraft, the Soviet Union constructed
many unmanned lighthouses and navigation beacons
powered by RTGs.[5]
......
One RTG, the SNAP-19C, was lost near the top of Nanda
Devi mountain in India in 1965 when it was stored
in a rock formation near the top of the mountain
in the face of a snowstorm before it could be
installed to power a CIA remote automated station
collecting telemetry from the Chinese rocket testing facility.
=======
rest:
https://en.wikipedia.org/wiki/Radioi...tric_generator
On Sat, 08 Dec 2018 21:04:59 -0000, Brian Gaff

wrote:

I'm sure you know this but the Voyager spacecraft are using
thermocouples
using the heat from decaying plutonium for power all the way out in
the
cosmos. it may be reducing now but its been one heck of a long time.

On Mon, 10 Dec 2018 14:39:31 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:

We do have nuclear power stations which can and do explode....

Those ones used on earth don't.

Tell that to those who lived near one that did explode, senile cretin! tsk

--
dennis@home to know-it-all Rot Speed:
"You really should stop commenting on things you know nothing about."
Message-ID:

On Mon, 10 Dec 2018 14:16:25 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:

FLUSH more of the usual troll **** unread

--
about senile Rot Speed:
"This is like having a conversation with someone with brain damage."
MID:

On 10/12/2018 09:20, Tim Streater wrote:
In article , Bruce Farquhar
wrote:

On Sun, 09 Dec 2018 23:28:59 -0000, danny burstein
wrote:

In "Bruce Farquhar"
writes:

Why are these not used on earth?

Do you really, really, want chunks of plutonium
or strontium 90i sitting around?

We do have nuclear power stations which can and do explode....

Wrong.

Well if you count a hydrogen explosion that happened because the staff
were not allowed too vent the hydrogen to the atmopshere because it
might be slightly radioactive...


--
Of what good are dead warriors? €¦ Warriors are those who desire battle
more than peace. Those who seek battle despite peace. Those who thump
their spears on the ground and talk of honor. Those who leap high the
battle dance and dream of glory €¦ The good of dead warriors, Mother, is
that they are dead.
Sheri S Tepper: The Awakeners.

On Mon, 10 Dec 2018 14:13:33 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:


If they had a room stat, how else would the stat tell the boiler to fire
up?

Doesn't have to be an electrical stat tho.

LOL You just HAVE to auto-contradict, regardless of how illogical the result
will be, eh, you abnormal ****ed up senile cretin?

--
Kerr-Mudd,John addressing senile Rot:
"Auto-contradictor Rod is back! (in the KF)"
MID:

On Mon, 10 Dec 2018 14:12:19 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:


Pounder has no hobbies.

Corse he does, post that steaming turd to all your posts.

That would beat opening the unwashed Scottish ******'s fly and sucking his
unwashed cock at every opportunity like you keep doing, senile Rot!

He just does as his wife tells him.

And does that your posts. Unlikely his wife tells him to do that.

Unlikely that ANYONE in rea life is talking to you ...or you wouldn't get up
every day between 1 and 4 o'clock in the morning just to continue with your
abnormal trolling on all these groups without too long a break, you abnormal
senile cretin!

BTW, don't you hope that you will EVER get away from me any time soon! I
will keep having fun slapping you despicable piece of senile **** around the
place for as long as you got the cheek to continue with your senile antics
on these groups! LOL

--
The Natural Philosopher about senile Rot:
"Rod speed is not a Brexiteer. He is an Australian troll and arsehole."
Message-ID:

On Mon, 10 Dec 2018 09:20:58 -0000, Tim Streater wrote:

In article , Bruce Farquhar
wrote:

On Sun, 09 Dec 2018 23:28:59 -0000, danny burstein wrote:

In "Bruce Farquhar"
writes:

Why are these not used on earth?

Do you really, really, want chunks of plutonium
or strontium 90i sitting around?

We do have nuclear power stations which can and do explode....

Wrong.

Are you an ostrich or something? I don't read the news much, but even I know many nuclear power stations have ****ed up. Lemme see, 3 mile island, Chernobyl, that one in Japan....