| 摘要 |
PURPOSE:To decrease the numbers of circuits and terminals and to make the titled circut suitable for circuit integration by calculating the difference potential between bias potentials of respective signals and applying addition/subtraction to the bias potential to hold the difference potential until the next blanking period. CONSTITUTION:In inputting signals alpha,beta from terminals 1,2, when the switch 24 is closed at blanking periods T,T of the signals alpha,beta, a differential amplifier 23 calculates the difference between bias potentials of blanking periods T,T and gives an output. The output is is fed back to a contact 8 of a line switch 5 via a buffer 25 of high input resistance and a bias resistor 26. Thus, the potential of contacts 7,8 of the switch 5 is equal in the blanking periods T,T. On the other hand, the potential fed back to the contact 8 is held by a holding capacitor 27 and also at signal output periods S,S till the next periods T,T. As a result, a signal of waveform E is outputted from a terminal 6. |
