This circuit was found in the February 1971 issue of Radio Electronics magazine. It is designed to power the previous circuit, providing a maximum current of around 50 mA.
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...