Originally suitable for photography applications, this circuit from a Popular Electronics from the 90s can also be used to time plate baths. The components are common, and the sensor is remote.
This circuit was found in the December 1995 issue of Electronics Now magazine. The circuit...
This circuit was found in a 1980 publication, but it can be assembled using a BD135 for Q1 or even...
This circuit source a voltage proportional to the number of the input pulses. The circuit has a...