This commercial receiver from the year 1958 uses two AA cells as Power supply. The circuit is intend to receive MW station and the transistors are germanium types not easy to find today.
The A3906 integrated circuit from Allegro MicroSystems (www.allegro.com) consists of a single-step motor...
We found this circuit in a 1980s publication on telephony. The circuit uses an integrated...
This circuit can use a pendulum sensor. We found this configuration in a 1994 publication. The...