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 sophisticated audio generator with digital display was found in the March 1984 issue of Radio...
This circuit is intended to trigger an alarm when the input voltage exceeds one value and to...
This receiver can operate with the transmitters shown in previous articles and even others...