An Electronic, Battery-less Dice





Introduction: An Electronic, Battery-less Dice

Update: A complete Instructable for this is here: Faraday For Fun: An Electronic Batteryless Dice

A Microcontroller, AVR Tiny13 based electronic dice, that does not use any battery or any normal power source. Instead it derives its power from a voltage generator based on the Faraday principle using a coil wound over a tube and a magnet inside the tube. To use the dice, just shake the circuit a few times and it produces a random number between 1 and 6 and displays it on the LEDs. Background music: Por Una Cabeza by Carlos Gardel



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    you could lose the diodes and use a smaller "goldcap"

    Diodes are necessary to convert the alternating voltage being produced by the Faraday generator into DC voltage to power the circuit. The current implementation doesnt use a Goldcap, but a normal electrolytic capacitor, 4700uF. Using a goldcap, even a smaller value goldcap, would require too much shaking to charge up the capacitor.

    You can see all the details of this in the new Instructable I posted:
    Faraday For Fun: An Electronic Batteryless Dice

    use a denser coil and neodymium magnet also i always thought caps could smooth AC to DC (hence their ample use in power supply filtering) anyways i have used caps before on a nixie PSU i made to do just that; of course it was full DC some AC remained but if it saves you components; especially since u unload DC cap into the LEDs it doesnt matter i think...

    Yes inductors can be used to acquire power supply filtering than capacitors alone. The ting to keep in mind is that a coil design that make a good filter, may not make a coil that works well for power generation, and vise versa. At this low power of power production using an inductor could sap away too much power, beside extreme filtering isn't needed here. BTW; neodymium magnets are used in this project .

    ohh now i understand you shake it and that charges the cap and thats what powers it. very nice but wont that make ac current not dc?

    Most if not all mechanical means of creating electrical current first produce AC. Than that AC is the turned into DC. In some generators by the mechanical switching provided by an commutator, and brushes that act as a high speed mechanical switch. In other generators rectifiers are used. As Gadre stated solid state rectifier are used with this generator

    it makes AC current but, you use 4 diodes in the circuit to regulate the alternating currents.

    That was a nice demonstratable, but isn't it supposed to be an instructable?