Found in a 1970 American publication, this circuit uses transistors of the time. These transistors may be replaced by current equivalents. The factor Q is greater than 3 000.
This circuit was obtained in an English magazine from 1979, but it can be easily assembled with...
The selected circuit was obtained in a Texas Instruments opto-electronics manual. The transistors can be...
This circuit latches when the liquid level of a reservoir reaches the sensors. The transistor can be...