Electrically energizable control system for a fuel burner

Claim 2

An electrically energizable control system for a fuel burner, including: a. an igniter; b. a controlled switching device effective, when gated, to connect said igniter to a source of electrical energy for providing pulses of electrical energy to said igniter; c. a gate circuit for said controlled switching device, said gate circuit including a gate capacitance for providing gate signals to said controlled switching device so long as said capacitance has a charge below a predetermined level, said capacitance initially being provided with a charge of at least the predetermined level; and d. first timing means effective, after a predetermined period of energization of said control system, to reduce the charge on said gate capacitance below the predetermined level whereby said controlled switching device is gated to operatively connect said igniter to the source of electrical energy only after the predetermined period of energization of said control system.

Claim 3

A control system as set forth in claim 1, wherein: a. said gate capacitance is provided with an incremental charge each time said gate circuit provides a gate signal to said controlled switching device so that gate signals to said controlled switching device through said gate circuit stop upon the total incremental charge reaching the predetermined level; b. said first timing means thereafter being effective to again reduce the charge on said gate capacitance below the predetermined level after another predetermined period of energization of said system whereby said controlled switching device again is gated to operatively connect said igniter to a source of electrical energy.

Claim 4

A control system as set forth in claim 2, further including second timing means effective, after said first timing means has reduced the charge on said gate capacitance a predetermined number of times, to disable said first timing means from again effecting reduction of the charge on said second capacitor to below the predetermined level.

Claim 5

An electrically energizable control system for a fuel burner, including: a. an igniter; b. a storage capacitance for providing pulses of electrical energy to said igniter; c. a controlled switching device connected in controlling relationship between said capacitance and said igniter; d. a circuit for connecting said storage capacitance to a source of electrical energy to build a charge on said storage capacitance for thereafter providing a pulse of electrical energy to said igniter; said circuit including switch means; e. actuating means for said switch means to cause said switch means to be closed only when said actuating means is energized; f. said actuating means being connected in parallel with said controlled switching device so that said switch means is maintained open in the event said controlled switching device conducts upon initial energization of said system.

Claim 6

An electrically energizable control system for a fuel burner, including: a. an igniter; b. a storage capacitance for providing pulses of electrical energy to said igniter; c. a controlled switching device connected in controlling relationship between said capacitance and said igniter; d. a circuit for connecting said storage capacitance to a source of electrical energy to build a charge on said storage capacitance for thereafter providing a pulse of electrical energy to said igniter; said circuit including switch means; e. actuating means for said switch means to cause said switch means to be closed only when said actuating means is energized; f. said actuating means being connected in parallel with said controlled switching device so that said switch means is maintained open in the event said controlled switching device conducts upon initial energization of said system.

Claim 7

A control system as set forth in claim 4, further including: a. a gate circuit for said controlled switching device, said gate circuit including a gate capacitance for providing gate signals to said controlled switching device so long as said gate capacitance has a charge below a predetermined level, said gate capacitance initially being provided with a Charge of at least the predetermined level; and b. first timing means effective, after a predetermined period of energization of said control system, to reduce the charge on said gate capacitance below the predetermined level whereby said controlled switching device is gated to operatively interconnect said storage capacitance and said igniter only after the predetermined period of energization of said control system.

Claim 8

A control system as set forth in claim 5, wherein: a. said gate capacitance is provided with an incremental charge each time said gate circuit provides a gate signal to said controlled switching device so that gate signals to said controlled switching device through said gate circuit stop upon the total incremental charge reaching the predetermined level; b. said first timing means thereafter being effective to again reduce the charge on said gate capacitance below the predetermined level after another predetermined period of energization of said system whereby said controlled switching device again is gated to operatively interconnect said storage capacitance and said igniter.

Claim 9

A control system as set forth in claim 6, further including second timing means effective after said first timing means has effected reduction of the charge on said gate capacitance a predetermined number of times, to disable said first timing means from again effecting reduction of the charge on said gate capacitor to below the predetermined level.

Claim 10

An electrically energizable control system for a fuel burner, including: a. valve actuating means for a fuel valve to enable flow of combustible fuel from the burner; b. a spark igniter for igniting fuel emitted from the burner; c. a first supply circuit for connecting said valve actuating means and a controlled switching device to a source of electrical energy to energize said actuating means upon conduction of said controlled switching device; d. a storage capacitance; a second supply circuit for connecting said storage capacitance to the source of electrical energy to build a charge on said storage capacitance; e. an ignition circuit interconnecting said storage capacitance, said igniter and said controlled switching device for discharging electrical energy from said storage capacitance through said igniter to cause ignition of fuel emitted from the burner upon conduction of said controlled switching device; f. a gate circuit for said controlled switching device, said gate circuit including a gate capacitance for providing gate signals to cause said controlled switching device to conduct so long as said gate capacitance has a charge below a predetermined level, said gate capacitance initially being provided with a charge of at least the predetermined level; and g. first timing circuit including means effective, after a predetermined period of energization of said control system, to reduce the charge on said gate capacitance below the predetermined level whereby gate signals are provided to said controlled switching device through said gate circuit only after the predetermined period of time.

Claim 11

An electrically energizable control system for a fuel burner, including: a. valve actuating means for a fuel valve to enable flow of combustible fuel from the burner; b. a spark igniter for igniting fuel emitted from the burner; c. a first supply circuit for connecting said valve actuating means and a controlled switching device to a source of electrical energy to energize said actuating means upon conduction of said controlled switching device; d. a storage capacitance; a second supply circuit for connecting said storage capacitance to the source of electrical energy to build a charge on said storage capacitance; e. an ignition circuit interconnecting said storage capacitance, said igniter and said controlled switching device for discharging electrical energy from said storage capacitance through said igniter to cause ignition of fuel emitted from the burner upon conduction of said controlled switching device; f. a gate circuit for said controlled switching device, said gate circuit including a gate capacitance for providing gate signals to cause said controlled switching device to conduct so long as said gate capacitance has a charge below a predetermined level, said gate capacitance initially being provided with a charge of at least the predetermined level; and g. first timing circuit including means effective, after a predetermined period of energization of said control system, to reduce the charge on said gate capacitance below the predetermined level whereby gate signals are provided to said controlled switching device through said gate circuit only after the predetermined period of time.

Claim 12

An electrically energizable control system as set forth in claim 8, further including: first switch means for selectively connecting said first and second supply circuits to the source of electrical energy and electrically energizable actuating means for said first switch means, said first switch actuating means being connected in parallel with said controlled switching device so that said first switch means will be closed to supply electrical energy to said first and second supply circuits only if said controlled switching device initially is nonconductive.

Claim 13

An electrically energizable control system as set forth in claim 8, wherein: a. said gate capacitance is provided with an incremental charge each time said gate circuit provides a gate signal to said controlled switching device so that gate signals to said controlled switching device through said gate circuit stop upon the total incremental charge reaching the predetermined level; b. a detection circuit, including a flame detection means, for providing gate signals to said controlled switching device independent of the incremental charge on said gate capacitance, upon said flame detection means sensing combustion of fuel emitted from the burner.

Claim 14

An electrically energizable control system as set forth in claim 8, wherein: a. said gate capacitance is provided with an incremental charge each time said gate circuit provides a gate signal to said controlled switching device so that gate signals to said controlled switching device through said gate circuit stop upon the total incremental charge reaching the predetermined level; b. second switch means connected across said gate capacitance and effective, when closed, to reduce the charge on said gate capacitance below the predetermined level; c. said first timing circuit including a series arrangement of a voltage breakdown device and an electrically energizable actuating means for said second switch means, said first timing circuit also including a timing capacitance connected in parallel with said series arrangement to energize said second switch actuating means for momentarily closing said second switch means upon the charge on said timing capacitance reaching the firing voltage of said voltage breakdown device; d. third switch means effective upon substantial nonconduction of said controlled switching device to connect said first timing circuit to the source of electrical energy for charging said timing capacitance.

Claim 15

An electrical energizable control system as set forth in claim 11, further including a second timing circuit effective, after a period of time longer than said predetermined period of time, to prevent the charge on said timing capacitance from reaching the breakdown voltage of said voltage breakdown device.

Claim 16

An electrically energizable control system for a fuel burner, including: a. valve actuating means for a fuel valve to enable flow of combustible fuel from the burner; b. a spark igniter for igniting fuel emitted from the burner; c. a first supply circuit for connecting said valve actuating means and a controlled rectifier to a source of electrical energy for energizing said valve actuating means upon conduction of said controlled rectifier; d. a storage capacitance; a second supply circuit for connecting said storage capacitance to the source of electrical energy and capable of charging said storage capacitance to a level in excess of the voltage of the electrical supply; e. an ignition circuit interconnecting said storage capacitance, said igniter and said controlled rectifier for discharging electrical energy from said storage capacitance through said igniter to cause ignition of fuel emitted from the burner upon conduction of said controlled rectifier; f. a gate circuit for said controlled rectifier including a gate capacitance and a first voltage breakdown device, said gate circuit being connected between said storage capacitance and said controlled rectifier to provide a gate signal to cause conduction of said controlled rectifier upon the charge on said storage capacitance exceeding sum of the charge on said gate capacitance and the firing voltage of said first voltage breakdown device, said gate capacitance initially being provided with a charge sufficient to prevent gate signals; g. discharge switch means connected across said gate capacitance and effective, when closed, to reduce the charge on said gate capacitance to a level allowing gate signals to said controlled rectifier; h. first timing circuit including a series arrangement of a second voltage breakdown device and an electrically energizable actuating means for said discharge switch means, said first timing circuit also including a timing capacitance connected in parallel with said series arrangement to energize said actuating means for said discharge switch means for momEntarily closing said discharge switch means upon the charge on said timing capacitance reaching the firing voltage of said second voltage breakdown device.

Claim 17

An electrically energizable control system for a fuel burner, including: a. valve actuating means for a fuel valve to enable flow of combustible fuel from the burner; b. a spark igniter for igniting fuel emitted from the burner; c. a first supply circuit for connecting said valve actuating means and a controlled rectifier to a source of electrical energy for energizing said valve actuating means upon conduction of said controlled rectifier; d. a storage capacitance; a second supply circuit for connecting said storage capacitance to the source of electrical energy and capable of charging said storage capacitance to a level in excess of the voltage of the electrical supply; e. an ignition circuit interconnecting said storage capacitance, said igniter and said controlled rectifier for discharging electrical energy from said storage capacitance through said igniter to cause ignition of fuel emitted from the burner upon conduction of said controlled rectifier; f. a gate circuit for said controlled rectifier including a gate capacitance and a first voltage breakdown device, said gate circuit being connected between said storage capacitance and said controlled rectifier to provide a gate signal to cause conduction of said controlled rectifier upon the charge on said storage capacitance exceeding sum of the charge on said gate capacitance and the firing voltage of said first voltage breakdown device, said gate capacitance initially being provided with a charge sufficient to prevent gate signals; g. discharge switch means connected across said gate capacitance and effective, when closed, to reduce the charge on said gate capacitance to a level allowing gate signals to said controlled rectifier; h. first timing circuit including a series arrangement of a second voltage breakdown device and an electrically energizable actuating means for said discharge switch means, said first timing circuit also including a timing capacitance connected in parallel with said series arrangement to energize said actuating means for said discharge switch means for momEntarily closing said discharge switch means upon the charge on said timing capacitance reaching the firing voltage of said second voltage breakdown device.

Claim 18

An electrically energizable control system as set forth in claim 13, further including other switch means effective to connect said first timing circuit to the source of electrical energy only when said controlled rectifier is substantially nonconductive.

Claim 19

An electrically energizable control system as set forth in claim 14, further including: a second timing circuit having means effective, after said first timing circuit has effected momentary closing of said discharge switch means a predetermined number of times, to prevent the charge on said timing capacitance from reaching the firing voltage of said second voltage breakdown device.

Claim 20

An electrically energizable control system as set forth in claim 13, further including a detection circuit, including flame detection means, for providing gate signals to said controlled rectifier independent of the level of charge on said gate capacitance upon said flame detection means sensing combustion of fuel emitted from the burner.

Claim 21

An electrically energizable control system as set forth in claim 16, wherein: said controlled rectifier includes an anode, a cathode and a gate; said flame detection means includes an ultraviolet detector; and said flame detection circuit is connected between said anode and said gate and the voltage at said anode falls below the holding voltage of said ultraviolet detector each time said controlled rectifier is gated into conduction.

Claim 22

An electrically energizable control system as set forth in claim 13, further including additional switch means for selectively connecting said first and second supply circuits to the source of electrical energy and electrically energizable actuating means for said additional switch means; said additional switch actuating means being connected in parallel with said controlled rectifier so that said additional switch means will be closed to supply electrical energy to said first and second supply circuits only if said controlled rectifier initially is nonconductive.