Found in Motorola documentation from the 90s, this circuit makes use of a triac from that time. The circuit is for the 110 V mains but can be modified for other grid voltages.
We found this circuit in a Popular Electronics from the 80s. This circuit eventually doesn't work with...
This circuit consists of a 10 + 10 V symmetrical source that operates from a single 5V input. It is...
This circuit is from an English magazine of 1977. The circuit is still current, just using BC547...