Inexpensive Visitor Alarm

Inexpensive visitor alarm MISCELLANEOUS EQUIPMENT Miscellaneous 15-5-11 "It lets me know when anyone comes up my driveway," says Marvin Hammer, Bartow, Ma., about the inexpensive "visitor alarm" he made out of standard offthe-shelf components for less than $50. The alarm has a motion detector that senses any movement within 20 to 30 ft. When anything moves within its area of detection, it sets off a bell that rings for about 15 seconds. "The bell is very loud and I can hear it when I'm working at my shop, which is 400 ft. away. Before I installed this alarm, people could come and go and I wouldn't know it," says Hammer. Key component of the alarm is an out-door floodlight with a built-in motion detector. They commonly sell for about $15 apiece at discount stores and are designed to easily install in place of an existing light fixture. There's a screw-in floodlight on either side and a motion detector at the center. Hammer simply mounted the fixture on a wall alongside the driveway and then screwed out one of the floodlights and replaced it with a screw-in plug-in. He mounted an 8-in. dia. 12-volt bell (sells for $30 at Radio Shack) next to the fixture. The bell plugs into the screw-in socket with a small transformer of the type commonly used to power battery-powered tape recorders, radios, etc. Now when the motion detector senses movement, it lights up the remaining floodlight and sets off the bell. The unit can be adjusted to ring for a shorter or longer period. "It lets me know if anyone drops in - company, mailman, etc. - but also scares away potential burglars," says Hammer. Contact: FARM SHOW Followup, Marvin C. Hammer, 2001 E. F. Griffin Rd., Bartow, Fla. 33830 (ph 813 533-3617).

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