Peltier Chips as an electrical source?

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PRR5406
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Peltier Chips as an electrical source?

Post by PRR5406 »

I just picked up two Peltier chips off eBay with the thought of trying to use them to light an LED headlight. For those who aren't familiar with them, Peltier chips take a DC current and one side of the ceramic get hot while the other side gets cold. It's my understanding however, if you heat one side of the chip, it will produce sufficient current to light an LED on my locomotive.
This is a purely experimental proposal, and I don't know enough about the chips to write a doctoral dissertation - yet.
If a Peltier chip or series of chips were placed against the smokebox (375F+) of a steam loco, would it produce the desired current? Has anyone toyed with these chips for a similar application?
And yes, I may be mad.
"Always stopping my train, and risking my ankles, with American made, New Balance sneakers."
ChooChooChris
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Re: Peltier Chips as an electrical source?

Post by ChooChooChris »

They can make a couple watts but they work off the temp differential. So they will become lower and lower power as the plate heats up. You would need a heatsink and lots of air over the backside to keep it closer to air temp instead source temp
-Chris Srch---- Home track Tradewinds and Atlantic Railroad
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Bill Shields
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Re: Peltier Chips as an electrical source?

Post by Bill Shields »

Probably more trouble than worth. I looked at them a awhile ago and went back to batteries for headlight and whatnot.

When a battery goes dead, fixing is easy.
Too many things going on to bother listing them.
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rmac
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Re: Peltier Chips as an electrical source?

Post by rmac »

Interesting idea!

If I'm not mistaken, the current generation will depend on the difference in temperature between the hot side and cold side of the chip(s), not just how hot you can make the hot side. So while there's lots of waste heat floating around a steam locomotive, the bigger problem will probably be keeping the cold side cold.

Some kind of air cooled heat sink comes to mind, but I don't have any gut feel for how feasable that might be.

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ChooChooChris
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Re: Peltier Chips as an electrical source?

Post by ChooChooChris »

Could run a water cooler on oneside and preheat incoming tender water to cool it.
-Chris Srch---- Home track Tradewinds and Atlantic Railroad
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Bill Shields
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Re: Peltier Chips as an electrical source?

Post by Bill Shields »

As I said ..more trouble than worth :mrgreen:
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STRR
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Re: Peltier Chips as an electrical source?

Post by STRR »

Take a look at wood stove circulation fans. They run off peltier modules, the heat from the wood burner, and the heat sink allowing one side to remain cool so as to have the chip generate electricity. They run a small DC motor to turn a fan blade. The hotter the stove, the faster the fan spins. You should research the heat differential required to generate the power you need for your headlight. I believe they will be able to generate all you need and maybe more. Too much will burn out the lights.

Good Luck,
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Re: Peltier Chips as an electrical source?

Post by kcameron »

I wonder if the elephant ears would work as heat sinks for the cold side?
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PRR5406
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Re: Peltier Chips as an electrical source?

Post by PRR5406 »

Bill Shields is probably correct, but the fun of making something new and applicable is half the journey, right? I like the "elephant ears" smoke lifters idea. Thanks for the discussion and not qualifying my sanity on this topic.
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Bill Shields
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Re: Peltier Chips as an electrical source?

Post by Bill Shields »

So...it would be like the lights on an old British motorcycle.

Use a zener diode to bleed off extra voltage when running hot, and have the lights go dim when you are sitting because you have no airflow to cool the heatsink?

Once that is working, you can use the draught blower to pull air cold air through an eductor, and use the incoming eductor airflow to cool the heatsink, thereby getting more power output from the p chip to drive the lights, so that you can see the water level in the boiler while you are standing.

Or you could mount a small steam driven reciprocating air compressor, using excess steam to fill a small tank sitting in the tender water. The compressed air can then be used to preheat the feedwater. The now cool air can be used to blow across the heatsink when standing still, to in turn create the temp diff to drive the p chip.

Problem solved!

I think I have avoided creation of too many run on sentences....but I have clearly exposed my scrambled neurotic tendencies.
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NP317
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Re: Peltier Chips as an electrical source?

Post by NP317 »

And you can name it the
BS Rube Goldberg Peltier Lighting System.

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ChooChooChris
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Re: Peltier Chips as an electrical source?

Post by ChooChooChris »

Bill Shields wrote: Tue Jan 24, 2023 10:43 pm So...it would be like the lights on an old British motorcycle.

Use a zener diode to bleed off extra voltage when running hot, and have the lights go dim when you are sitting because you have no airflow to cool the heatsink?

Once that is working, you can use the draught blower to pull air cold air through an eductor, and use the incoming eductor airflow to cool the heatsink, thereby getting more power output from the p chip to drive the lights, so that you can see the water level in the boiler while you are standing.

Or you could mount a small steam driven reciprocating air compressor, using excess steam to fill a small tank sitting in the tender water. The compressed air can then be used to preheat the feedwater. The now cool air can be used to blow across the heatsink when standing still, to in turn create the temp diff to drive the p chip.

Problem solved!

I think I have avoided creation of too many run on sentences....but I have clearly exposed my scrambled neurotic tendencies.

You forgot to add use the compressed air to power a small piston to run a fan.
-Chris Srch---- Home track Tradewinds and Atlantic Railroad
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