This 1969 Electronics World power supply has 5 V to power digital circuits and a 170 V output for Numitron indicator valves used at the time.
This circuit is from 1993 documentation. The table provides the values of R3 and R4 according to...
One touch of the push button S1 and the circuit LEDs shown in the figure start to flash rapidly. The...
This circuit was obtained in a 90s American documentation. The integrated circuit used is uncommon...