This circuit was found in Mullard's transistor application manual from 1960. More modern transistors can be used. The zener diodes used have the indicated voltages.
The purpose of this circuit is to monitor the phase pulses of a logic circuit, checking if they...
This 1/2 hertz high selectivity filter was found in the December 1990 issue of Radio Electronics...
This circuit is from a 70s Burr Brown documentation. The components are from the time and the...