This circuit is from General Electric from the 80s, using a relay with high current contacts (20 A). The transistor admits equivalent, and any phototransistor can be used as a sensor.
This circuit was found in a 1999 documentation, but the components it uses can still be easily...
In the figure we have an application for NLAS5113, a new device from on Semiconductor...
The use of field effect transistors in this circuit improves its performance. This configuration is from a...