This circuit was suggested by an Electronic Design from the 90s. Its purpose is to detect resistance relationships in circuits with resistive sensors for control purposes, by firing a relay.
This circuit can be implemented with other operational amplifiers. The formulas for calculating the...
This circuit is from a 1953 publication, consisting of an AM radio with 3 germanium transistors that,...
The sensor of this circuit is a common silicon diode and it directly drives a small cooler with a...