| 摘要 |
<p>PURPOSE:To store efficiently and at a low cost the magnitude of a driving signal and a counter-electromotive voltage by eliminating a counter-elctromotive voltage component from the driving signal and fetching a digital signal, and also obtaining level information of two bits by comparing the counter- electromotive voltage with a limit value. CONSTITUTION:A solenoid driving signal A from an input terminal 11 is converted to a digital signal for showing on and off, after the counter- electromotive voltage component has been eliminated by a waveform shaping circuit 10 and inverted by aninverter 12 and an output signal C is obtained. On the other hand, the signal A is compared with the upper and the lower limits VREF1, VREF2 by comparators 13, 14, respectively, and in accordance with whether it is within a range of the upper and the lower limits or not, a binarization signal is outputted. By this output, FFs 15, 16 are set and reset, and signals F, H are obtained in an output Q. The signal F is brought to exclusive OR with the signal H and a signal G is outputted. When this signal G and H are stored in a storing circuit, and OR of both of time is fetched at the time of reproduction, each period of solenoid on and off signals can be known, and in which level the counter-electromotive voltage is can be known.</p> |
