GB2395027A - Thermoelectric generator using body heat - Google Patents

Abstract

A thermoelectric generator for items which can be worn on the body, such as wristwatches, A thermopile, which may include bismuth telluride or antimony telluride in a sandwich of plates, in good thermal conductive contact on one side with the casing 4 of a wristwatch produces a heat gradient when the item is worn on the body and the other side of the thermopile is in contact with the skin. The resulting electrical charge can be stored in a rechargeable battery 6 so that continuous power can be supplied even when the thermopile is removed from the heat source, ie the body of the wearer. Power generation by this means may be supplemented by a mechanical method, such as an inertial or a manual mechanism 9.

Description

, BODY HEAT GENERATOR

This invention relates to a wristwatch or other body-worn instrument or apparatus.

Wristwatches have for some time been powered electrically by a cell or battery. All cells or batteries become drained over time and have to be replaced.

According to the present invention a rechargeable battery can be supplied with power from a thermopile. A thermopile is an assemblage of dissimilar metals, conducting solids or semi-conductors, whose interfaces, when linked into an electrical circuit and heated in one part to produce a heat gradient, causes an electrical current to be generated. In this invention the thermopile takes the form of a sandwich of plates that form the base of a watch casing, although any other application can be powered by this means.

The exterior plate lies flat against and makes good contact with the skin and accordingly produces a heat flux. A heat gradient is thereby established across the plates which generate an electric current that is fed to a rechargeable battery. The battery powers the chronometric circuit or any other application.

In order to maximise the heat flux and therefore the current generated, the upper plate of the thermopile makes good thermal conductive contact with the rest of the watch casing in order to be cooled to the atmosphere.

This mode of power supply can be supplemented as or if required by the incorporation of a mechanical winder that turns a current generator. The mechanical winder can be either manually turned by a stem to the exterior of the casing, or by a 'perpetual' inertial apparatus which is set in motion by movement of the wearer.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: 1 is the skin-contact layer of the thermopile (such as Bismuth telluride) 2 is the intermediate material (such as Antimony telluride) 3 is the top layer of the thermopile (such as Bismuth telluride) in good thermal conductive contact with 4 the watch casing 5 is the circuit by which the thermopile supplies power to 6 the rechargeable battery, which in turn provides power through 7 its linking circuit to 8 the load, which can be the chronometric or another mechanism, with 9 the optional mechanical generator also supplying power to 6 through 10 the linking circuit

Claims (4)

1. A thermopile worn on the body with its inner surface in contact with the skin, the upper surface cooled to the air directly through vents, or by contact with the casing of an instrument, to produce a heat gradient.

2. A thermopile as claimed in Claim 1, integrated with and providing electrical

power through circuitry for a wristwatch or some other instrument or apparatus, such as transmitting or receiving equipment.

3. The thermopile powered instrument as claimed, which stores electric current in a rechargeable battery that supplies continuous power when the thermopile has been removed from its heat source.

4. A thermopile generator providing power to a storage battery, as claimed in Claim 3, which is supplemented by a mechanical generator, driven either by, I an inertial or a manual mechanism.