The configuration shown allows to obtain a high voltage gain for FETs. FETs can be BF245 or MPF102. The circuit is from the 1977 National Semiconductor FET Databook.
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...