This resistive sensor was found in a 1969 US documentation. The circuit uses transistors of the time, but current equivalents can be employed.
This sensitive field strength meter was found in 1993 documentation. The instrument may be the...
This circuit was found in a 1967 General Electric manual. It is intended for the control of high...
The figure shows how to vary the output voltage of a 7812 regulator between 12 V and 2 V less than...