We found this circuit in the magazine Eletcronics Now of July 1994. The power supply is according to the relay and the transistor can be any general purpose one.
May 2017 - Mouser Electronics already has inventory with ROHM BD570xx integrated circuits for...
We found this passive circuit in the February 1995 Electronics Now magazine. The circuit is...
This digital potentiometer is from a 1993 publication, but it can be easily assembled today. R1 to...