Found in a 1980s manufacturer documentation, this circuit can be used as an optical shield. The integrated circuit is from the era and modern equivalents can be tried out.
Indicated for applications with a PC, this circuit was found in an English documentation from...
This circuit was published in a 90s Radio Electronics. The circuit uses the well-known LM386 that...
This dimmer, from an old publication, can use almost any triac and in shooting a neon lamp. The...