This circuit makes use of a low impedance microphone. The relay is according to the supply voltage which can be between 9 and 15 V. The operational gain is approximately 100.
We obtained this circuit from a 1993 documentation. The circuit has 9 current ranges that are...
This FM receiver tuning step circuit was found in a 1960 documentation. No information about the...
This circuit consists of two stages that each shift 180 degrees the signal. The circuit was...