| 摘要 |
2136346 9324792 PCTABS00028 An electronic safety circuit for a portable gas heater includes a transformer (58) and half wave rectifier (60, 62) connected in parallel with a fan motor (26) for charging a capacitor (70), and a solid state switching circuit, which may be either a pair of cascaded transistors (73, 74), an SCR, or a Darlington switch, for applying a reverse polarity voltage across the solenoid (78) of a solenoid operated gas valve (36) to immediately turn off the gas valve (36) in the event of loss of power to the combustion fan motor (26). The electronic safety circuit may be conveniently mounted on a PC board and enclosed in the combustion fan motor.
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