| 摘要 |
PURPOSE:To compoensate correctly DC component fluctuation without causing abnormal locking by setting a control voltage to a prescribed value when out of synchronism is detected in a DC voltage control circuit compensating a drift component. CONSTITUTION:When a carrier causes out of synchronism because of loss of an input signal, a carrier asynchronizing detection circuit 7 detects out of synchronism, its output signal is inputted to a control voltage generator 6 to reset the control voltage 101 to the initial value. When the input signal is recovered again in this way, since the control voltage 101 is reset to the initial value, the carrier synchronism is established without causing abnormal locking for DC voltage control loops 3, 4, 6, then the reset of the carrier asynchronous detection circuit 7 is released to activate the DC voltage control loops 3, 4, 6. |
