The UVTRON tube is an ultraviolet radiation sensor. In this circuit from Radio Electronics from April 1990 we have a flame detector.
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...