This circuit is from a 1976 amateur radio manual. The transistor can be the BD136 and the frequency adjustment is done in a potentiometer. The supply can be done with voltages from 6 to 15 V.
This sensitive sound or noise activated key can be used in an alarm system. The circuit is from an...
This experimental flip-flip changes its state by the command of two push-buttons. The state is...
The transformer in this power supply can have a secondary winding from 1 to 15 A of current....