We found these circuits in a 90s Radio Electronics. In them, we have the way to turn a load on and off using pressure switches. The circuit can be used with other types of direct current load.
Disabling this circuit from a 2002 documentation can only be done by pressing 4 keys in a correct...
This circuit was found in a 1979 magazine. We can use any JFET like MPF102 or BF245. The relay is 12 V...
This circuit was obtained in a 90’s documentation. The operational amplifiers are from that time....