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Alarms and security circuit diagrams
June 22, 2010
This is an infrared gate with two sensors planned to use in the wall in the way behind a door. [more]
June 22, 2010
This electronic lock can be used with any type of iButtons you may already have, since the only thing needed is the internal serial number, that's different for every iButton. [more]
June 22, 2010
A crucial failing of proximity detectors is their unreliable and tricky nature. This is where they are used to detect humans, not to speak of smaller living beings. [more]
June 22, 2010
This circuit is an Electronic Locker. It is controlled by a switches combination (by a code). There is a switch matrix on the door of the locker. [more]
April 11, 2010
These are two - easy to build - relay-based alarms. You can use them to protect your motorcycle - but they have many more applications. If you use relays with 6-volt coils - they'll protect... [more]
April 11, 2010
This is a universal four-digit keypad-operated switch - with a difference. Instead of entering the security code one number at a time - the four keypad buttons must be pressed simultaneously. Split the code between... [more]
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