This circuit was obtained in a 1970 engineering documentation. The operational is the 741, but other operational ones can be used. The power supply must be symmetrical.
The sensor of this circuit is an NTC and the indication is made on a common analog indicator, and...
This 1.2 to 32 V x 3 A regulator was found in an 80's EDN. The power components must be equipped...
This circuit turns off after a time that depends on C1. The circuit is from an Electronics Now...