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What the World Needs Now --
Candle Flame Powered Battery Charger
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Previous Issues |
Thermoelectric devices have been
around for a long time. By running electrical current through them, one side
gets hot while the other gets cold. Many are used to cool sodas in a cooler,
keep a computer’s processor cool and have even been used on spacecraft. When
run backwards, by applying heat to them, they can also produce electricity. I would
sure love to see a well designed thermoelectric generator, which could produce some
electricity from the heat of a candle flame. I would only expect a watt or two of
power at most from this system, so the power would level would only be good for
charging up a cell phone battery or maybe powering an emergency radio. It
could also power one or two high output white light emitting diodes (LEDs) for
emergency illumination. The light from those devices would produce far more
light than the light from a single candle flame. |
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As illustrated, I imagine a
thermoelectric device sandwiched between a copper plate and a massive heat sink. The
assembly would be mounted on a ceramic foam insulator, which would act as a
pedestal. Heat from the candle flame at one end of the plate would be
routed to the bottom of the thermoelectric wafer at the other end. This
indirect heating method should increase the efficiency by keeping the heat of
combustion away from the heat sink. |
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An
insulating shield along the side of the heat sink would add additional protection from
excess heat from the candle flame. An adjustable stand would be used to keep the
flame just below the copper plate, as the wax was burned. |
The
direct output current from the thermoelectric generator may have to be boosted to a higher
more common voltage, using a DC to DC converter circuit. Many cell phone batteries
are charged through the phone from a +5v source. Other devices, like MP3 players and
some radios may also be powered by +5v. If the device could be kept going for 24
hours, some 50 watt-hours of electrical energy might be produced. This might even be
enough to charge up the battery of a small laptop computer. |
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Thermoelectric
Generator |
Massive Heat Sink |
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