optically coded key

Posted on Feb 6, 2014

The optical key works as an infrared door opener for house, garage and the likes. Diagram 27. 0 functions as the key. It is a transmitter module which sends out a modulated infrared (IR) beam. The modulating frequency can be adjusted through P1. Diagram 27. 1 is the actual lock (receiver module). It uses a phototransistor to receive the IR beam comi

optically coded key
Click here to download the full size of the above Circuit.

ng from the key transmitter module. It compares the modulation frequency of the transmitter beam to its internal frequency. When the two frequencies match, the relay is activated, thereby opening whatever elecric door lock is connected to it.

Leave Comment

characters left:

New Circuits



Popular Circuits

Background music decoder
AC Arduino dimming circuit
British Police Car Siren circuit diagram
Decibels Meter Circuit Using LM324
Electronic Transformer Applications
Homemade Metal Detector Kit
Automatic Room light Control With Bi Directional Visitor Counter