PURPOSE: To stop the combustion of the burner when the burner is used continuously for a long time to supplement an incomplete combustion preventing device by providing a timer circuit which operates a solenoid valve disposed in a gas passage of the burner when a switch which is turned ON and OFF in linkage with the igniting operation is turned ON, and turns OFF the solenoid valve after the lapse of a predetermined time.
CONSTITUTION: When a switch 2 is turned ON upon ignition operation a current is allowed to flow to a solenoid valve 8 by detecting a difference in electromotive force between a pilot thermocouple 4 and a reverse bias thermocouple 5. Simultaneously, a timer circuit 9 operates. A reference voltage is produced by resistors r1 and r2 on the non-inverting input side of an operational amplifier IC, and a CR charging circuit is produced by a resistor r3 and a capacitor C on the inverting side of the operational amplifier IC. When the switch 2 is turned ON to start changing of the capacitor, and the inverting input voltage of the operational amplifier IC becomes higher than a reference voltage, the output of the operational amplifier IC becomes from a high level to a low level, and an AC output from a comparator 6 is erased. Hence, no current flows to the solenoid valve 8, and as a result the valve 8 is closed to stop the combustion. Accordingly, by selecting the constants of the resistor r3 and the capacitor C, the switch 2 is turned ON and the time until the solenoid valve 8 is closed can be suitably selected.
| JP7166134 | Combustion device |
| JPS5929921 | COMBUSTION SAFETY CONTROLLER |
| JP3141022 | CONTROLLER FOR COMBUSTOR |
KUBO KOSAKU
NISHIYAMA TAKAO
UNO SHIGEKI
| JP53138245B | ||||
| JPS5966617A | 1984-04-16 | |||
| JP60160357B |