Little Black Box

Little Black Box MISCELLANEOUS EQUIPMENT Miscellaneous 19-4-9 "I'm a fish farmer and I need power 24 hrs. a day for my operation. I put together this little black box that lets me know when the power goes off at any time of the day or night," says Doug Holmes, Gunton, Manitoba. "It's easy to make yourself. The parts are available from any electrical parts supplier and the wiring is simple. There are no transistors, resistors or other hard parts to wire in. It simply plugs into a 110-volt wall outlet. "It consists of a 120-240-volt coil re-lay and a 9-volt battery powered buzzer. The relay is wired through the coil and a regular male plug plugs into the wall receptacle. As long as the power is on, the electrical current holds the relay open. If the power goes off, the relay closes, activating the 9-volt buzzer circuit. "The battery usually lasts 2 or more years depending on use. Once a month, I pull it out of the wall receptacle to test it. If the alarm is ever activated because of a loss of power, there's a toggle switch on the unit so you can shut off the alarm without pulling it out of the receptable. "I make these units for sale for $39.95 (Canadian)." Contact: FARM SHOW Followup, Doug Holmes, Box 29, Gunton, Manitoba, ROC 1HO Canada (ph 204 886-2363).

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