| 摘要 |
PURPOSE: A shut-down delay relay is provided to improve a characteristic of the shut-down delay relay by forming a delay time setup circuit, a latch circuit, and an LED display circuit. CONSTITUTION: An output terminal of a time constant circuit including a diode(D6), a fixing resistor(R6), a variable resistor(VR), and a condenser is connected to input terminals of inverts(Q2,Q3) of a latch circuit. An output terminal of the latch circuit is connected to a gate of a field effect transistor(FET) through an inverter(Q6) and a fixing resistor(R3). A drain of the field effect transistor(FET) is connected to a ground portion. A source of the field effect transistor(FET) is connected to a coil of a relay(RL). A collector of a transistor(Q1) is connected to the latch circuit. An emitter of the transistor(Q1) is connected to the ground portion. A base of the transistor(Q1) is connected to an output contact point of a relay(RL) through a resistor(R8). The output contact point of the relay(RL) is connected to an input portion of the latch circuit through a photo coupler(P.T). An output portion of the latch circuit is connected to a static voltage circuit through an inverter(Q7) and a light emitting diode(LED).
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