The integrated circuit used in this detector is uncommon today. We found it in a documentation from the 70s. Detection is done by an optical camera with LEDs and a photo sensor.
What differentiates the CIR8139 circuit is the use of two inverter ports to trigger the transistor that...
The battery charger suggested in the figure has its current limited by resistor R1. This component may...
This circuit with increased power output was found in the November 1974 Radio Electronics...