Using the 723 integrated circuit, this power supply has the voltage determined by R2 and R3, which can be changed. The circuit is from a Radio Electronics magazine from July 1971.
Frequencies up to just over 100 kHz can be obtained with an oscillator based on one of the four...
This circuit, found in a Popular Electronics from 1992, is based on an oscillator and a crystal...
This is a discrete equivalent version of an open collector TTL gate. What we have is an inverter...