This shield circuit can be used in several applications that involve a feedback signal. The circuit is from American documentation from the 80s and the transistors are according to the loads driven.
The microphone for this circuit, found in a 1967 Japanese documentation, must be ceramic or...
This is the circuit of a robot published in the June 1992 issue of Radio Electronics magazine. The sensors...
We found this peak audio indicator in a 1980 publication. The M1 indicator can be 200 uA with the...