The UVTRON tube is an ultraviolet radiation sensor. In this circuit from Radio Electronics from April 1990 we have a flame detector.
This circuit, for a bulb of 6 V up to 200 mA, was found in an old Argentine publication of the...
Found in a 1968 documentation, this small amplifier was very popular at the time being used in...
This circuit can drive a loudspeaker with near 1 W of Power from 6 to 9 V supplies. The circuit...