# US 9,752,990 B2 · Low-powered system for driving a fuel control mechanism > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,990 B2 - Document ID: US9752990B2 - Status: Granted - Kind: B2 - Application number: 14/042,269 - Filed: 2013-09-30 - Published: 2015-04-02 - Granted: 2017-09-05 - Earliest claimed: 2013-09-30 - Assignees: Honeywell International Inc. - Applicants: Honeywell International Inc. - Inventors: Brent Chian; David Kucera; Trevor C. Haag; Timothy J. Nordberg; Adam Foley - Web page: https://patentgrep.com/patent/US9752990B2 ## CPC - G01N 21/78: producing a change of colour - F23N 1/002: {using electronic means (F23N1/04 - F23N1/10 take precedence)} - F23N 5/242: {using electronic means} - F23N 2223/08: Microprocessor; Microcomputer - F23N 2231/02: using electric energy accumulators - F23N 2231/10: for component failures - F23N 2231/18: Detecting fluid leaks - F23N 2231/22: using warning lamps - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - F23N: REGULATING OR CONTROLLING COMBUSTION (control devices specially adapted for combustion apparatus in which combustion takes place in a fluidised bed of fuel or other particles F23C10/28; condition responsive controls for regulating combustion in domestic stoves with open fires for solid fuel F24B1/187) ## 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 ### Claim 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. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 2) 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. ### Claim 4 (depends on 3) 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. ### Claim 5 (depends on 3) The circuit of claim 3, wherein: the first, second, third, fourth and fifth switches are transistors; and the charge storage device is a capacitor. ### Claim 6 (depends on 5) 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. ### Claim 7 (depends on 2) 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. ### Claim 8 (depends on 7) The circuit of claim 7, further comprising a single DC-to-DC converter connected to the thermally activated power source. ### Claim 9 (depends on 8) 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. ### Claim 10 (depends on 1) The circuit of claim 1, wherein the thermally activated power source comprises a thermopile device. ### Claim 11 (depends on 10) The control circuit of claim 10, wherein the thermopile device comprises two or more serially connected thermocouple devices. ### Claim 12 (depends on 7) The circuit of claim 7, wherein the microcontroller is an ultra-low-power microcontroller. ### Claim 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. ### Claim 14 (depends on 13) 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. ### Claim 15 (depends on 13) The system of claim 13, wherein the certain electronic signal comprises not perfectly in phase input signals. ### Claim 16 (depends on 13) 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.