This is a typical circuit of a PROM programmer from the 70s. It appeared in the magazine Radio Electronics in 1979. Note that the programming was done manually byte by byte using switches.
The purpose of this circuit is to amplify the signal of a medium or high impedance microphone,...
Taking advantage of the two stable states of a tunnel diode it is possible to build a switching circuit...
We found this circuit in a 90s Electronic Design. The components admit current equivalents. The circuit...