Found in an American 1980s documentation, this circuit compares signals from two TTL sources, providing an output that depends on the frequency difference. The circuit can be used as a shield.
This interesting circuit for analog TV selects the first line of a frame. The circuit was found in a...
This circuit was found in a 1967 EEE. The components are from that time, but the circuit can be...
Found in a 1968 documentation, this circuit provides symmetrical voltages determined by component...