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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    34 Discussions

    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?

    2 replies

    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.

    Oops, mea culpa: I didn't realize that videos and slideshows [ aren't intended to be instructables] and should not be construed as such. (Replying to my own post so others can be similarly educated.)

    I didn't know either and i thank you for posting that re-reply

    I read your "Programming and Customizing the AVR micro" - nice project.

    I found the video. I saved this as a favorite and then looked it up and clicked on it and when it loaded it showed the video link. So now I just need help to build one. Nice show and tell but no info to build one. Why did you put it on Instructables if all you wanted was to show it off? I really hope you add the missing info to it.

    To anyone: I use Internet Explorer but do not see any video link. I just see a box titled "enbed code" and the box with the email, print, favorite and flag links in it with all the comments listed under the box. This sounds like a simple project but I am a beginner. I do not know what an AVR Tiny 13 base is. I would like to see a schematic and this video (where ever it is). I hope you will help me and all the others who want more info. Thanks for anything.

    Great project. Question on the linear alternator: are you doing a full-wave rectifier to produce dc? Also, there is no such thing as a "radially magnetized" neo magnet. How are you getting the magnetic flux to travel through the coil perpendicularly? Binding the magnets south-to-south and north-to-north with iron spacers would concentrate the flux radially (doable, but tough) this is a fundamental weekness in all shake designs I've seen. Thanks for the vid though.

    could it be hack?to the owners advantage? i still trust the traditional dice

    very, Very VERY cool im might build it if i can get everything from my local radioshack, do they sell neodymium magnets and leds there?

    1 reply

    You can get neodymium magnets from Leds from Radioshack, yeah sure.