This circuit is for old telephones with analog lines. It was found in the May 1988 Radio Electronics magazine. The circuit is powered by the line signal voltaje.
This VCO or Voltage Controlled Oscillator uses common components. TR1 can be a BF245 and TR2 a...
This circuit was found in a 1967 RCA publication. The circuit uses components from that time, and...
Here is a very simple and economical electronic game. Using only one integrated circuit and one...