Found in a 90s Radio Electronics, this circuit uses a ceramic capacitor (C1) as a sensor. The operational amplifier is a double 741 of the time.
The configuration shown in the figure uses two NPN transistors activating the load when the input...
It is a 13.8 V x 10 A regulator obtained in a 2008 documentation. The 2N3055 transistors must be...
This timer of 10, 25, 45 seconds and 5 minutes has its times selected by the keys. The circuit drives...