This is the receiver from the previous alarm system. The circuit is from Radio Electronics, April 1989, and has an LDR as the sensor. Optical devices should be used to improve performance.
This circuit uses a 7812 and another regulator integrated circuit that is not very common...
The project is from a 1992 publication, but totally current by the components it uses. The LEDs...
We have a simple and useful circuit found in a 1982 documentation which generates a signal in the...