| 摘要 |
PURPOSE:To prevent creeping with an extremely simple circuit constitution by stopping the output of count pulses when the level of a DC voltage corresponding to electric energy is smaller than a specific value. CONSTITUTION:The output of a voltage detecting circuit 1 and the output of a current detecting circuit 2 are inputted to a voltage and current multiplying circuit 3 and multiplied mutually and a rectifying circuit 4 outputs a DC voltage E1 corresponding to momentary electric power. This DC voltage E1 is inputted to a voltage and frequency converting circuit 5, which outputs digital pulses of frequency corresponding to the level of the DC voltage E1. Then, a flip-flop circuit 6 outputs pulses P0 with a repetitive period T0 twice as long as the repetitive period T of the digital pulses from its Q terminal based on the digital pulses P. A comparator 7, on the other hand, outputs a reset signal S to the flip-flop circuit 6 when the DC voltage E1 drops below the reference voltage E from a reference voltage setting circuit 8 to stop the output to count pulses P1. |
