This touch-controlled circuit was found in English documentation from the 1970s. The components used are common today.
Lamps in the range between 20 and 50 mA can be used. Voltage supply is according the lamp and...
Found in an October 1992 Radio Electronics magazine article, this circuit generates a low-power tone in...
We found this circuit in the Motorola Linear Databook of 1993. It is the traditional configuration with...