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.
Found in a 1963 documentation, this circuit employs germanium transistors of the time. Transformer and...
In the figure we have a way of receiving ultrasonic signals of a single frequency using a PLL 567....
This traditional circuit generates a 200 Hz sinusoidal signal. The frequency depends on the...