2MHz astable (CB9102E)

This TTL circuit can be used as a shield. The frequency can be changed by changing the capacitors.

Optical Isolator Power Switch (CB12413E)
This solid-state relay (SSR) or shield was found in a 1995 Electronics Now. The transistor can be...
Twilight Simulator (CB26055E)
This circuit simulates dusk by slowly dimming an incandescent bulb. It was found in the August 1998...
TTL Oscillator 7404 (CB25016E)
We found this circuit in December 1986, Radio Electronics magazine. It uses 3 inverters and has...