This circuit uses an optocoupler with a phototriac or optotriac to drive an external triac. The circuit is from a Radio Electronics magazine from December 1989.
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...