Applications for this circuit include hearing aid, stethoscope, etc. Transistors are general purpose and powered by a single 1.5 V battery.
This circuit was found in the March 1979 issue of Radio Electronics magazine. Integrated circuits must...
This is the transmitter for a remote-control system published in the August 1986 issue of Radio...
The current drained by this circuit, from a 1976 documentation, is 3 mA and the cut-off frequency is...