Low-powered system for driving a fuel control mechanism

• US 9,752,990 B2
• Filed: 09/30/2013
• Issued: 09/05/2017
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Chian, Brent, Kucera, David, Haag, Trevor C., Nordberg, Timothy J., Foley, Adam
• Primary Examiner(s): Jackson, Stephen W
• Application Number:
  US14/042,269
• Publication Number:
  US 20150090310A1
• Time in Patent Office: 1,436 Days
• Field of Search: 361160
• CPC Class Codes: F23N 1/002 using electronic means F23N1/04 - F23N1/10 take precedence
• CPC Class Codes: F23N 2223/08 Microprocessor; Microcomputer
• CPC Class Codes: F23N 2231/02 using electric energy accumulators
• CPC Class Codes: F23N 2231/10 for component failures
• CPC Class Codes: F23N 2231/18 Detecting fluid leaks
• CPC Class Codes: F23N 2231/22 using warning lamps
• CPC Class Codes: F23N 5/242 using electronic means
• CPC Class Codes: G01N 21/78 producing a change of colour

Abstract

A low powered system for providing sufficient current to a fuel control mechanism drive. The system may have a fuel control mechanism pick circuit that has an energy storage mechanism for providing a large amount of current for a short time to the fuel control mechanism drive. A safety switch may be enabled with a special signal to let current flow to the fuel control mechanism drive to operate a corresponding fuel control mechanism for controlling fuel to a pilot light or heating element. The pilot light or heating element may provide heat to a thermoelectric source that generates electrical power from the heat. The electrical power may go to a single DC-to-DC converter and voltage clamp for providing a voltage source to a microcontroller and other circuits of the system. The pick circuit may prevent a harmful reverse flow of current from the storage mechanism to the thermoelectric source.

Claims

1. A control circuit comprising:

a thermally activated power source;

a valve pick circuit connected to the thermally activated power source;

a safety switch circuit connected to the valve pick circuit; and

a valve drive circuit connected to the safety switch circuit; and

wherein;

the valve pick circuit comprises a charge storage device, a first switch for preventing current flow back to the thermally activated power source, and a second switch for allowing current to flow from the charge storage device to the safety switch circuit; and

the safety switch circuit requires not perfectly in phase input signals to turn on a third switch for allowing the current to flow from the second switch to the valve drive circuit.

2. The circuit of claim 1, wherein:

the charge storage device is charged to at least a first voltage before a valve pick time of the valve pick circuit;

the first switch is off during the valve pick time of the valve pick circuit;

the third switch is connected to the first and second switches and the charge storage device through the second switch; and

a fourth switch is for receiving the not perfectly in-phase input signals to turn on the third switch.

3. The circuit of claim 2, wherein:

the valve drive circuit comprises;

a fifth switch connected to the third switch; and

a first terminal connected to the fifth switch, for a connection to a first valve; and

when the charge storage device is charged to at least the first voltage, the valve pick time begins and the second, third and fifth switches are turned on, current flows from the charge storage device via the first connection to a first valve.

4. The circuit of claim 3, wherein a magnitude of the current to the first valve ranges from one to three times a minimum magnitude of current needed to operate the first valve.

5. The circuit of claim 3, wherein:

the first, second, third, fourth and fifth switches are transistors; and

the charge storage device is a capacitor.

6. The control circuit of claim 5, wherein:

the first, third and fifth transistors are N-channel field effect transistors (FETs); and

the second transistor is an NPN bipolar transistor; and

the fourth transistor is a PNP bipolar transistor.

7. The circuit of claim 2, further comprising:

a microcontroller; and

wherein the microcontroller provides the not perfectly in phase input signals to the fourth switch to turn on the third switch.

8. The circuit of claim 7, further comprising a single DC-to-DC converter connected to the thermally activated power source.

9. The circuit of claim 8, further comprising a voltage clamping circuit connected to an output of the single DC-to-DC converter and to the input of the microcontroller.

10. The circuit of claim 1, wherein the thermally activated power source comprises a thermopile device.

11. The control circuit of claim 10, wherein the thermopile device comprises two or more serially connected thermocouple devices.

12. The circuit of claim 7, wherein the microcontroller is an ultra-low-power microcontroller.

13. A flame control system comprising:

a power source;

a reverse current protection circuit connected to the power source;

an energy storage circuit connected to the reverse current protection circuit;

a safety switch connected to the energy storage circuit; and

a drive circuit, for a fluid control mechanism, connected to the safety switch; and

wherein providing a certain electronic signal to the safety switch permits current to flow from the energy storage circuit through the safety switch to the drive circuit for the fluid control mechanism.

14. The system of claim 13, further comprising:

a microcontroller connected to the energy storage circuit and the safety switch; and

wherein the microcontroller provides the certain electronic signal to the safety switch for permitting current to flow from the energy storage circuit through the safety switch to the drive circuit for the fluid control mechanism.

15. The system of claim 13, wherein the certain electronic signal comprises not perfectly in phase input signals.

16. The system of claim 13, further comprising:

a microcontroller connected to the energy storage circuit;

a single DC-to-DC converter connected to the power source; and

a clamping circuit connected to the single DC-to-DC converter and the microcontroller; and

wherein;

the power source comprises a thermoelectric generator;

the fluid control mechanism comprises a fuel valve connected to a flame generator;

the flame generator, upon receipt of fuel and ignition, can heat the thermoelectric generator to provide electrical power; and

the energy storage circuit comprises a capacitor.