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.
We can control the frequency of an oscillator from digital circuits or from the output of a...
We recommend adding a 470-ohm resistor in series with the potentiometer in this dimmer circuit...
We found this circuit for old tape recorders in the December 1972 Radio Electronics magazine. The...