| 摘要 |
PURPOSE:To discriminate easily the polarity of a transformer in a short time by providing a pulse generator at the primary side of the transformer, and a circuit which decides on the plus-minus polarity of a voltage and a latch circuit which latches its result at the secondary side. CONSTITUTION:The output signal of an operational amplifier OPA is applied to comparators CMP1 and CMP2 and compared with reference comparison voltages Vr1 and Vr2. When a plus pulse voltage is induced, the CMP2 outputs, 1, which is applied to the set terminal of an FF2 through an AND circuit A2, so the FF2 is set and 1 appears at a terminal 1. An FF1 is not set, so its terminal Q is still held at 0. Therefore, an output terminal 13A is at 0 and a terminal 13B is at 1, so the transformer T to be measured is still in a plus connection state. Further, when the FF2 is set, its terminal Q is held at 0, the output signal of an AND circuit A1 is still 0 even if the signal of the CMP1 goes up to 1, and the FF1 is not set. Namely, the FFs 1 and 2 are controlled so that they do not malfunction after the polarity discrimination.
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