Found in an Australian documentation from 1991, this circuit was sold in a kit at the time. It is a small FM transmitter with a very common configuration, also found in other projects on this site.
This simple motor control for alternating current with triac was obtained in a European...
This source is a variation of the previous one, using two Zen diodes to stabilize the output...
This circuit was found in an 80's General Electric documentation. The circuit uses uncommon...