This commercial earphone receiver was manufactured in the 1960s in Japan. It was powered by a 9 V battery and the transistors were made of germanium.
We found this light relay circuit in year 2000 documentation. The relay is 6 V and the circuit...
We found this circuit in the Linear Technology Applications of 1997. The circuit uses components from...
We have dozens of similar projects in articles and circuits on this site. This is from Radio...