This circuit uses an optocoupler with a phototriac or optotriac to drive an external triac. The circuit is from a Radio Electronics magazine from December 1989.
We found this circuit in an old documentation for hams. In it we have the way to use a varicap to...
This small amplifier, with output less than 1 W, was found in a 1960 transistor manual from...
Found in a Hands On Electronics from the 90s, this circuit can be easily assembled today, as the...