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.
The purpose of this circuit is to improve the reception of signals from the short-wave band. The...
This highly sensitive light sensor was found in a 1970 General Electric documentation. The circuit...
This circuit was found in a Popular Electronics from the 90's. The CMOS integrated circuit used is...