How to Create a Magnetic Switch Electronics Project
A Sneaky Switch for Everyday UseBy Cy Tymony
Make Magazine: Vol. 7, p. 51
Have you ever dreamed about having the power to turn on and off household appliances and electronics with a wave of the hand? Then this one's for you. Make Magazine brings you the art of making a magnetic activator and a super stealth sneaky switch so you can make the magic happen.
Step 1: Make a Magnetic ActivatorYou'll want a strong magnet to activate devices from at least an inch away. Tiny rare earth magnets can be found in most micro radio-controlled cars and in the packaging of some hearing aid batteries. Glue a magnet to the face of a ring or a wand or affix it to some object so that when it's near the switch, or moved away, it will cause the desired effect.
Step 2: Make a Magnetic SwitchIn this magnetic switch, the paper clip lies across a "spring" of rolled tape, one end hovering just above the aluminum foil and the other end taped down. (A small piece of foam can also be used as the spring.) When a magnet passes over the switch, it tugs the clip to touch the foil, completing the circuit. Connect a switch to a 3V watch battery to light an LED, buzzer or other low-current devices and toys.
Step 3: Connect Switch to a RelayYour magnetic switch can be attached to a relay to control devices that need higher current. Mount your switch and relay behind the dashboard to secretly activate a cut-off switch, alarm or other car accessories. Or, hook your switch to an X-10 controller and universal interface module to control a variety of appliances. Pretty sneaky!
Step 4: Detect Counterfeit MoneyLegitimate currency has iron particles in the ink. Fold a bill so that half of it stands up vertically – If the top edge moves toward your magnet, it's the real deal. If not, phone the Secret Service!
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