this got me when i was kid and built a wire coil magnetizer. I burned up my model train power supply. the little details like enamel coating are what get you. I spent so many hours perfectly winding that coil too. I can never have that time back. i think that may be the point in life that i became jaded. had that not happened, i would probably have grown the process to the degree that i was able to build my emp weapon that displaces the iron atoms in the human body, shredding humans where they stand and not damaging structures. The world would have bowed to my will..... those tiny details ruin everything
On Sun, Nov 3, 2019 at 1:24 PM Ken Hohhof <[email protected]> wrote: > If Radio Shack still existed, you could pick up a spool of “magnet wire”, > thin stuff with enamel insulation. 26 or even 32 AWG should be fine for > lighting an LED. Mount that cardboard tube on a lathe or drill and put a > whole bunch of turns on it. > > > > Faraday’s law says voltage should be proportional to number of turns times > rate of change of magnetic flux. Size of cardboard tube doesn’t explicitly > show up in that equation, but I think Bill is right, because if you > visualize the flux lines from the magnets, they would only factor into the > equation if they loop around the coil of wire. If the coil is too wide or > too long, some of the flux lines will stay inside the coil or will cut > through it rather than looping around the ends. The too long problem is > not as big of a problem because it just means the dropping magnets will > include voltage for a longer time interval. > > > > > > *From:* AF <[email protected]> *On Behalf Of *Bill Prince > *Sent:* Sunday, November 3, 2019 12:38 PM > *To:* [email protected] > *Subject:* Re: [AFMUG] OT: Induction coil voltage > > > > The diameter of the tube and the size of the magnets will also affect how > much voltage you get out of the thing. Try to minimize the air gap around > the slug/magnets as much as possible. Use a smaller diameter tube or a > larger diameter slug/magnets. > > > > bp > > <part15sbs{at}gmail{dot}com> > > > > On 11/3/2019 9:51 AM, Adam Moffett wrote: > > I'd bet I have 20-30 turns of 16ga wire....that's just what I happened to > find first. I could tear apart some CAT5 and use the 24ga inside so I can > get more turns in the same area. Or I can find something with a > transformer inside and unwind the super skinny wire on it. I just don't > know to what extent I need to go to make this thing work. > > And yeah it's not obvious in the picture I sent, but you're supposed to > connect the two LED's together short leg to long leg so that one of them > lights up when you drop the magnet North first and the other lights up when > you drop it South first. > > I'd wondered about the length of the pulse too. It's a cheapo digital > multimeter. It does not read the same on each drop of the magnet. When I > say it read 30mV that's just the highest number I saw after several drops. > > -Adam > > > > On 11/3/2019 12:40 PM, Ken Hohhof wrote: > > > I would think yes, although it seems the electrical pulse will be very > brief and I’m not sure you’ll be able to measure it with a meter. Also > have you determined the polarity of the DC generated or tried hooking up > the LEDs both directions? > > In any case, I’d think wrapping the entire length of the cardboard tube > with wire would make the LEDs light up for a longer time and be more > visible. > > How many turns do you have on it now? > > *From:* AF <[email protected]> <[email protected]> *On Behalf > Of *Adam Moffett > *Sent:* Sunday, November 3, 2019 11:20 AM > *To:* [email protected] > *Subject:* [AFMUG] OT: Induction coil voltage > > I wanted to do this science experiment with the kids. My problem is my > LED's don't light up. It's from a discontinued textbook. Apparently they > sold a kit with the materials for all the projects, but that's no longer > available so I'm scrounging in the garage. > > I put a volt meter on the rig and I was only getting 6mV when I dropped > the magnet. I doubled the number of coils on the tube and then doubled the > number of neodymium magnets and I'm getting closer to 30mV now, but I need > closer to 2V to light up an LED, so I'm wondering what would increase the > voltage by two orders of magnitude. Is it based on the number of turns in > the coil? > > > > > -- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com >
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