This electronic rheostat with SCR was found in the June 1964 Radio Electronics magazine. The SCR may be a modern type and the 2W potentiometer may be 470 ohms.
Found in American documentation from the 90s, this configuration detects the direction of rotation...
This amplifier with a 9 MHz passband and 10 voltage gain with two transistors was found in...
A Schmitt trigger inverter can be obtained from each gate of the 4093 with the connection shown in the...