This inductance bridge uses an external audio signal. The circuit is from a Radio Electronics from January 1966. The instrument can be a common multimeter in the lowest current range.
This sophisticated alarm with traditional components was found in an ancient American...
This circuit is from a Fairchild digital clock module shown in the March 1977 issue of Radio...
This circuit was obtained in a Radio Shack documentation from 1977. It can be used as a multimedia...