| 摘要 |
PURPOSE:To attain a stable operation by converting an input signal into a pulse width signal, detecting the leading/trailing of the pulse width signal and inputting the detected output to a photocoupling circuit so as to decode a desired signal thereby decreasing the power required for isolation. CONSTITUTION:A digital signal inputted from a digital circuit is fed to a digital/ pulse width conversion circuit 1 and a voltage signal inputted from an analog circuit is fed to a voltage/pulse width conversion circuit 2. The signal (a) subjected to pulse width conversion is inputted to a leading/trailing detection circuit 3 and a detected pulse signal (b) operates the photocoupling circuit 4. The circuit 4 generates an output pulse signal bb having the same waveform as that of the signal (b) and the isolation is applied in the circuit 4. A frequency division circuit 5 inputs the signal bb, a pulse width/digital conversion circuit 6 converts a frequency division output C1 or C2 into a digital signal or a pulse width/voltage conversion circuit 7 converts the signal into a voltage signal, and then the result is sent. Thus, the power required for isolation is decreased to attain the stable operation. |
