US 2010/0075264 A1 · Redundant Ignition Control Circuit and Method

Abstract

A redundant ignition control system and method for gas burning appliances is provided. The system utilizes a main processor and a supervisory processor to provide the redundant, fail safe operation of both the pilot valve and the main gas valve of the appliance. Three switching elements under the control of the two processors, as well as the use of high pass filters to block DC from the gas control valves provide redundant, fail safe operation. The use of variable duty cycle or frequency pulse width modulated signals enables use in low power applications and ensures system safety. Inclusion of a gas valve verification sequence, ignition sequence, burner monitoring sequence, and heat shutdown and standby sequences ensures safe, low power operation during normal control, and fail safe operation upon the failure of any component of the system.

Claims20

Dependent claims

A ignition control system for use with intermittent pilot systems for gas burners having a pilot gas valve and a main gas control valve, comprising:

a main processor;
a supervisory processor;
a gas valve supply switch controllably coupled to the supervisory processor, the gas valve supply switch having a power input and a gas valve supply output;
a pilot valve switch controllably coupled to the main processor, the pilot valve switch having a first gas valve supply input coupled to the gas valve supply output and a pilot valve power output;
a main gas valve switch controllably coupled to the main processor, the main gas valve switch having a second gas valve supply input coupled to the gas valve supply output and a main gas control valve power output;
and
wherein the main processor is configured to generate a pulse width modulated mode control signal to control operation of the supervisory processor, the main processor further configured to sense the gas valve supply output to verify proper operation of the supervisory processor.

4 more elements

A ignition control system for use with direct spark systems for gas burners having a main gas control valve, comprising:

a main processor;
a supervisory processor;
a gas valve supply switch controllably coupled to the supervisory processor, the gas valve supply switch having a power input and a gas valve supply output;
a main gas valve switch controllably coupled to the main processor, the main gas valve switch having a gas valve supply input coupled to the gas valve supply output and a main gas control valve power output;
and
wherein the main processor is configured to generate a pulse width modulated mode control signal to control operation of the supervisory processor, the main processor further configured to sense the gas valve supply output to verify proper operation of the supervisory processor.

3 more elements

Dependencies are inferred from the claim text.

Redundant Ignition Control Circuit and Method

Life of this patent

Redundant Ignition Control Circuit and Method

Life of this patent

Abstract

Claims20