摘要 |
A microprocessor-based power switching circuit responds to a common form of noise by disconnecting power from the controlled apparatus. The microprocessor provides an alternating voltage when power is to be provided, and the alternating voltage is converted by a detector circuit to a voltage close to ground which cuts off a transistor. When the transistor is cut off, an interface circuit places a thyristor which performs the actual power switching, into conduction. Noise on the base of the transistor can only drive it into conduction which then puts the thyristor into non-conduction.
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