This telephone recording circuit was found in the June 1979 issue of Radio Electronics magazine. The components are common at the time and the power is supplied by the power grid.
Vishay's VCNL4200 integrated circuit consists of a fully integrated proximity detector containing...
This circuit samples the current in a load and in case of excessive value it activates a...
The frequency of this oscillator depends on the crystal used and the transistors. The circuit was...