We found this circuit in the Encyclopedia of Electronic Circuits Volume 5 from 1995. It uses a 3-terminal transducer from the time. The circuit is triggered by light.
This circuit was found in Radio Electronics from the 90s. The transducer is a tweeter and the...
This circuit, obtained from a 1989 publication, can control motors up to 1.5 A. With the LM350 this...
We found this circuit in 2005 Linear Technology documentation. The integrated circuit is LT1787...