Thermoelectric generator with starting circuit

Patent metadata

Field	Value
Publication number	US-11081956-B2
Application number	US-201816035917-A
Country	US
Kind code	B2
Filing date	Jul 16, 2018
Priority date	Jul 17, 2017
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

A thermoelectric generator includes a voltage source including a thermoelectric element, a starting circuit connected to the voltage source, a DC to DC converter circuit connected to the voltage source, an output connected to the starting circuit and connected to the DC to DC converter circuit, and a controller having an input connected to the voltage source, and outputs connected to the starting circuit and to the DC to DC converter circuit. The controller deactivates the starting circuit and activates the DC to DC converter circuit when a voltage at the output or when a voltage provided by the voltage source rises above a predefined upper voltage threshold. Additionally, the controller reactivates the starting circuit and deactivates the DC to DC converter circuit when a voltage at the output or when a voltage provided by the voltage source drops below a predefined lower voltage threshold.

First claim

What is claimed is:

1. A thermoelectric generator comprising:
a voltage source comprising a thermoelectric element,
a starting circuit connected to the voltage source,
a DC to DC converter circuit connected to the voltage source,
an output connected to the starting circuit and connected to the DC to DC converter circuit, and
a controller having an input connected to the voltage source, and outputs connected to the starting circuit and to the DC to DC converter circuit,
wherein the controller is configured:
to deactivate the starting circuit and to activate the DC to DC converter circuit when a voltage at the output or when a voltage provided by the voltage source rises above a predefined upper voltage threshold, and
to reactivate the starting circuit and to deactivate the DC to DC converter circuit when a voltage at the output or when a voltage provided by the voltage source drops below a predefined lower voltage threshold.

2. The thermoelectric generator according to claim 1 , wherein the DC to DC converter circuit comprises a boost converter having at least one inductor and at least a first switch controlled by the controller.

3. The thermoelectric generator according to claim 2 , wherein the DC to DC converter circuit comprises a second switch controlled by the controller, and wherein one end of the second switch is connected to the output and another end of the second switch is connected to the inductor.

4. The thermoelectric generator according to claim 3 , wherein the first switch and the second switch of the DC to DC converter circuit are metal oxide semiconductor transistors and wherein one of the first switch and the second switch is an NMOS transistor, the other one of the first switch and the second switch being a PMOS transistor.

5. The thermoelectric generator according to claim 1 , wherein the starting circuit comprises a transformer, a third switch and a rectifier, the third switch being a metal oxide semiconductor depletion transistor, and a secondary side of the transformer being connected to the rectifier and to a gate of the depletion transistor.

6. The thermoelectric generator according to claim 5 , wherein a primary side of the transformer is connected to a drain of the third switch and to the voltage source.

7. The thermoelectric generator according to claim 5 , wherein the third switch comprises a gain lower than 1 and wherein the transformer has a gain larger than 1, the product of the transformer gain and the gain of the depletion transistor being larger than 1.

8. The thermoelectric generator according to claim 5 , further comprising a fourth switch in series with the third switch and wherein the fourth switch is controlled by the controller.

9. The thermoelectric generator according to claim 8 , wherein the fourth switch is a metal oxide semiconductor transistor having a channel resistance value below 100 mOhm at a gate-source voltage of 0 V.

10. The thermoelectric generator according to claim 8 , wherein the controller comprises a capacitor arrangement comprising at least two capacitors to store a negative voltage configured to operate the fourth switch.

11. The thermoelectric generator according to claim 1 , wherein the controller comprises a pulse width regulation regulator.

12. The thermoelectric generator according to claim 1 , further comprising an output capacitor connected to the output and providing an electric energy supply for the controller.

13. A mobile or portable electronic device comprising:
the thermoelectric generator according to claim 1 .

Assignees

• Swatch Group Res & Dev Ltd

Inventors

• Gueissaz Francois

Classifications

• H02M3/1552

  Boost converters exploiting the leakage inductance of a transformer or of an alternator as boost inductor · CPC title

• H01M8/182

  Regeneration by thermal means · CPC title

• H02M3/158

  including plural semiconductor devices as final control devices for a single load · CPC title

• H02M1/088

  for the simultaneous control of series or parallel connected semiconductor devices · CPC title

• H02M3/1582

  Buck-boost converters (H02M3/1584 takes precedence) · CPC title