This PLL with operational amplifiers was found in 1969 documentation. The configuration can be adapted to use modern components. The circuit has a gain of 15 V / V and can operate with 10 kHz signals.
Found in a 1964 Electronic Design, this circuit suppresses arcs that occur in contacts when a...
The circuit that gave rise to this configuration is from 1978. In the original publication are...
As a reference for restorers, this is the circuit of a digital clock with the TSM201 module. The...