Found in a Popular Electronics from the 90s, it applies to the old answering machines that used tapes. It emits a warning beep on the drive.
This solid-state relay (SSR) or shield was found in a 1995 Electronics Now. The transistor can be...
This circuit simulates dusk by slowly dimming an incandescent bulb. It was found in the August 1998...
We found this circuit in December 1986, Radio Electronics magazine. It uses 3 inverters and has...