초록 ▼

A burner control system in which signals indicating the condition at various locations within the system are applied to a control circuit in the form of pulse trains, causing a continuous alternation of state of solid state switching elements therein. The system actuates a switch to open a fuel valv

A burner control system in which signals indicating the condition at various locations within the system are applied to a control circuit in the form of pulse trains, causing a continuous alternation of state of solid state switching elements therein. The system actuates a switch to open a fuel valve only when the level of the control circuit output signal is alternating, indicating that the said switching elements are operative. A comparison circuit compares the control circuit output signal with a signal denoting the condition of the fuel valve, to ensure proper operation of the fuel valve switch.

대표청구항 ▼

In a burner control system having a fuel control device, and a sensor adapted to sense a condition in the system and to provide a signal denoting said condition, the improvement comprising a fail-safe, self-checking system for controlling said fuel control device, comprising: a control circuit, said

In a burner control system having a fuel control device, and a sensor adapted to sense a condition in the system and to provide a signal denoting said condition, the improvement comprising a fail-safe, self-checking system for controlling said fuel control device, comprising: a control circuit, said control circuit having an input terminal for reception of said condition signal, logic for processing said condition signal, an output terminal, and solid state switching means connected in circuit between said input terminal and said output terminal, said control circuit adapted to produce a control signal at said output terminal in response to the condition signal at said input terminal, means for cyclically alternating the state of said switching means, and thereby providing a cyclically alternating level of the control signal at said output terminal in response to said condition signal, an actuating circuit connected between said output terminal and the actuator of said fuel control device, and adapted to provide an actuating signal for said fuel control device in response to a cyclically aalternating control signal level at said output terminal, but not otherwise, a comparison circuit to compare the output signal of said condition signal processing logic with a signal denoting the condition of said fuel control device, and means actuated by said comparison circuit when the said compared signals are incompatible to override said actuating signal for said fuel control device.