Our latest Weekend Project is a great lesson in turning a cheap consumer product into a magical maker device. Mystery Electronic Switches converts an electronic holiday greeting card with LEDs (along with the aide of a couple magnetic reed switches and various other components) into a portable gadget and magic trick that will both astound and confuse whomever you challenge to turn this device on. The secret (Spoiler Alert!) lies in the use of a magnetic ring, which in combination with the reed switches, allows you, and only you, to complete the circuit. The physical Single Pole Double Throw (or “SPDT) switches mounted to the exterior of the chassis must also align to allow voltage to pass through correctly. Just to confuse your audience, we’ve installed a dummy switch in the middle – feel free to use this to further confuse any challengers who think they might have figured out the sequence.
The exact card you hack will vary, but the premise remains the same. The circuit is turned on when the card is opened, so this function is replaced by toggle switches. Once you’ve located the trigger on the greeting card’s circuit board (pictured above), you will know where to connect all of the additional circuitry (see schematic below). Then you package it all up in your own chassis – in our demo we used a clear plastic deodorant container. This looks cool and will awe your audience when you perform your “magic.” They won’t be looking at your hands. Instead they’ll be looking for something to be happening inside. Meanwhile only YOU know the secret!
See all of the RadioShack Weekend Projects posts (to date)