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.
This solid-state relay (SSR) or shield was found in a 1995 Electronics Now. The transistor can be...
The output current of this circuit reaches 12 mA. The zener diode determines the output voltage. The...
In the figure we have an IF amplifier step using a MOSFET. The circuit was found in a 1980s...