Automatic phase control circuit - has switching stage and filter which compares mean phase differences with limits and controls oscillator

摘要

A circuit provides automatic adjustment of control time constants. A phase detector generates first signal representing a control deviation allocated to the phase difference between input and output signals generated in an oscillator. A filter determines the phase control time constants. The first signal is applied to the filter which delivers to the oscillator second signals representing the control variable. The circuit has a switching stage (SS) to which the first signals (RE) are applied, and which determines the mean phase differences during a specified period and compares them with at least one limit. It delivers control signals (ST) to the filter (FA), by which greater or smaller control time constants are set when the mean phase differences do not reach or exceed the limits.