| 摘要 |
PURPOSE: A circuit for alarming door-open state of a refrigerator is provided to inform users of the door-open state by lightening interior light and producing alarm sound after a predetermined time from the lightening of the interior light. CONSTITUTION: A circuit for alarming door-open state of a refrigerator comprises a drop -transducer(20) for rectifying alternating current applied to a power supply(10) of the refrigerator by a full wave rectification circuit, a photothyristor(30) to be turned on if a light signal is detected when the door is opened, a transistor(40) to be turned on in response to the turn-on of the photothyristor, a relay switch(50) connected with an interior light(60) to be turned on for lighting in response to the turn-on of the transistor, a microcomputer(70) for outputting a high signal after a predetermined time relay according to a light detection signal output from the photothyristor, and an alarm outputting unit(80) for emitting a predetermined alarm sound according to a control signal transmitted from the microcomputer.
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