This circuit was found in an American publication from 1965. The circuit uses components from that time. No information was given about the excitation transformer. Observe the high input power.
This long-time circuit uses a field effect transistor, which may be the BF245, and depends on a...
The figure shows how to implement the AND function with a Norton LM3900 operational amplifier. The number of...
This circuit is from an old documentation, but it can be elaborated with ease, since the...