Incandescent phone charger?

[T i m]

Hi all,

I was chatting with daughter and her b/f about lights and lighting and the efficiencies of different types etc. She then asked "why can't we actually use the heat from a std lamp for something useful" (other than heating your house etc).

That set me thinking that could you (in theory) make say a table lamp with a 'shade' made from some thermoelectric power generator material and therefore have that waste heat charge your phone or summat?

I'm not (seriously) suggesting this as an alternative to CFL's , or that this would be the ideal or practical use of the technology etc, just wondered if it could work?

Cheers, T i m

p.s. I have a small Peltier chip here and am always amused how little voltage it takes to burn one finger whilst freezing another and at the same time. ;-)

[Owain]

You could in practice. I think oil lamps were used to power radio receivers, in wartime?

[Andy Dingley]

Enthalpy. Then the maths gets hard.

The hand-waving version is that "Hot" is useful in a way that "Warm" isn't. Even when the total energy is the same, i.e. a kilogram that's

10=BAC warmer is much more useful than 10kg that's only 1=BAC warmer.

[therustyone]

a few of decades ago you could buy a Russian thermocouple gizmo which fitted on top of oil lamp and would power a transistor radio. Handy in the Urals and cosmetically satisfying.

rusty.

[The Natural Philosopher]

lovely idea for a ditzy eco-gimmick: Mamod steam engine hooked to a dynamo. Would do more than most PV panels anyway.

Use a light bulb to heat the boiler...

[Tabby]

Yes, and it works. You could try it quite easily.

But what... the efficiency of thermocouples is very low, and they cost money. And jsut how useful is a low voltage lower power output that only comes on a bit after you switch the light on?

NT

[Harry]

Well we used to heat our pies in a wire basket propped over the upturned inspection lamps at work. Light, hot pies and a nice smell wafting over the shop floor.....

[T i m]

Hmmmmm ...

Thanks for all the replies guys and I'll pass the projects and examples back to daughter.

Only goes to show there are few new ideas in the world. ;-)

Cheers, T i m

[Rick Hughes]

Hmmm ....

why not use efficient lights, that don't put out heat ... and then charge via normal charger ...

[Chris Hogg]

or to drive a Stirling cycle engine.