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 simple speed control for 3 to 15 V motors uses a common power transistor. The circuit was...
The SN76477 integrated circuit of the 1980s was a great success as a sound effects generator. Many...
This circuit with 10 MHz and 1.25 MHz TTL outputs was found in an American documentation from the...