Found in an American publication from 1968, this circuit can be made based on a TIP42 that must be mounted on a heat sink. The transformer is 25 V with a current of 3 to 4 A.
This circuit provides a signal of higher frequency the greater the intensity of the light incident on...
This circuit was obtained from a 1978 Practical Wireless. It generates a low frequency, low...
This circuit can be used as a lockable shield. A pulse activates the relay that remains on even...