This is the receiver for the previous transmitter. The microphone is of the high impedance ultrasonic type. The circuit activates a relay. The operational amplifier supports equivalent.
The purpose of this circuit is to amplify the signal of a medium or high impedance microphone,...
Taking advantage of the two stable states of a tunnel diode it is possible to build a switching circuit...
We found this circuit in a 90s Electronic Design. The components admit current equivalents. The circuit...