Sarahisme Posted May 22, 2005 Share Posted May 22, 2005 hey all i am interested in trying to make my own little generator (a hobby type thing). however first i thought that i would look into some of the physics behind it. (i think faraday's law or something is involved) but i have not learnt anything in school yet about doing this kind of thing and was wondering if anyone would like to help me out a little bit with doing or designing this? Cheers Sarah Link to comment Share on other sites More sharing options...
5614 Posted May 22, 2005 Share Posted May 22, 2005 A basic electrical generator just has a magnet inside a coil.... either hand held or powered by a turbine. But I don't think that's quite what you are asking... maybe?!? Link to comment Share on other sites More sharing options...
Sarahisme Posted May 22, 2005 Author Share Posted May 22, 2005 umm well what i was thinking is yeah rotating a coil in a magnetic field, or vica-versa, (doesnt make much of a difference does it?, whichever is easier to move i suppose)... but its all the equations and laws that i am not sure which ones of those i should be using? Link to comment Share on other sites More sharing options...
5614 Posted May 22, 2005 Share Posted May 22, 2005 It doesn't make much of a difference no, its the relative speed you're looking for. I'm not sure if there's a difference between rotating a magnet and pulling it in and out of a coil. What kind of equations are you looking for? Link to comment Share on other sites More sharing options...
RICHARDBATTY Posted May 22, 2005 Share Posted May 22, 2005 Just a quick thought. A rotating magnet requires no rotating contacts and will be easier to make. Link to comment Share on other sites More sharing options...
Sarahisme Posted May 22, 2005 Author Share Posted May 22, 2005 hmm yeah i guess rotating the magnet is the better option. the kind of equations, i spose faraday's law of induction and magnetic flux laws, i am just not quite sure how to put them all together :S Link to comment Share on other sites More sharing options...
calbiterol Posted May 22, 2005 Share Posted May 22, 2005 You could attach it to a stirling engine. If you want suggestions on the actual construction (which I don't think you do, seeing as you asked to the maths and principles behind it) it might be better to have this thread moved to the engineering section. Link to comment Share on other sites More sharing options...
Sarahisme Posted May 22, 2005 Author Share Posted May 22, 2005 how do i move it to the engineering section? Link to comment Share on other sites More sharing options...
calbiterol Posted May 23, 2005 Share Posted May 23, 2005 Email a mod and ask them to move it to the engineering section (tell them the thread name and location). Link to comment Share on other sites More sharing options...
akcapr Posted May 23, 2005 Share Posted May 23, 2005 a generator is just a motor that you spin. take an electric motor, spin it like with your hands, and measure the voltage coming from the electrodes. Link to comment Share on other sites More sharing options...
Sarahisme Posted May 23, 2005 Author Share Posted May 23, 2005 ok, yeah but how does the physics work behind that, i want to do both really, build and have a least a moderate understanding of what i am actually doing Link to comment Share on other sites More sharing options...
YT2095 Posted May 23, 2005 Share Posted May 23, 2005 you don`t have to limit yourself to a rotational design, you could use a linear "Push-Pull" design also.akcapr is quite right, a permanent magnet motor will serve perfectly well as a generator (I made a small petrol gen with an electric wheelchair motor the same way). so if you can lookup how to make an electric motor (the sort you can do at home for a school science project) your on your way the most simple types use a couple of bar magnets a large paperclip some enamelled wire and a few nails and some wood (and your little 6 volt lantern battery). a Linear design would be a plastic tube in which fits a bar magnet on a plunger, around the outside of the tube are many windings of wire, as the magnet moves in and out of the tube, a current is induced in the wire. hope that helps a little Link to comment Share on other sites More sharing options...
Sarahisme Posted May 23, 2005 Author Share Posted May 23, 2005 thanks for that YT2095, sounds interesting for the actually real-life building of it, what about on a sorta powering a small home scale, how would that be designed? in a simliar way i suppose, but with bigger components? Link to comment Share on other sites More sharing options...
5614 Posted May 23, 2005 Share Posted May 23, 2005 Well on a national scale a power generator has, well, it varies: Burning things make steam turns turbine, turbine moves magnet in a coil.... basically it's about getting a turbine to turn, be it by burning something, wind turning it, water turning... once you've got rotation it just puts that into the magnet, possibly a gear system is used to get the magnet to move faster. Link to comment Share on other sites More sharing options...
YT2095 Posted May 23, 2005 Share Posted May 23, 2005 more or less yes the one I made did 36 volts at 5 amps using a 33cc chainsaw petrol engine. I think for homes and the like they use deisel engines and much larger generators, but you can buy the small petrol ones for a song now, they`ll do 240vac output and depending on the requirement any thing from a few amps right up to enough to run a fairground ride or two oh yeah, and if you use stepper motors (the sort you find in printers) you can even have 2 or 3 or more phase output too, I made a small wind generator using one of those Link to comment Share on other sites More sharing options...
Sarahisme Posted May 23, 2005 Author Share Posted May 23, 2005 cool! i gather you understand all the physics behind how all the stuff works then? Link to comment Share on other sites More sharing options...
YT2095 Posted May 23, 2005 Share Posted May 23, 2005 the principals yes, but DO NOT make me do maths! Link to comment Share on other sites More sharing options...
Sarahisme Posted May 23, 2005 Author Share Posted May 23, 2005 lol, thats my current feeling, well i suppose i just need to know which equations i need to use and then try and work it out from there... so if anyone can give me a few to start with that'd be great! Link to comment Share on other sites More sharing options...
YT2095 Posted May 23, 2005 Share Posted May 23, 2005 the only one I can remember is Flemings left hand rule. there`s obviously alot more to it than that, but it`s a foot in the door at least Link to comment Share on other sites More sharing options...
Sarahisme Posted May 23, 2005 Author Share Posted May 23, 2005 yeah thats a start, thanks Link to comment Share on other sites More sharing options...
5614 Posted May 23, 2005 Share Posted May 23, 2005 Well if you had an AC output you could use a transformer... although, well, in the UK mains frequency is 50Hz, I don't know if you could get to that frequency by hand only, so you may need a more industrial-style generator. hmm, I've looked on google and can't find any useful formulae... I'd say buy a powerful magnet (and big!) and get a lot of low resistance (enamel maybe?) wire make a coil and try it out. Powerful magnets are not cheap though, NIB (neodiyum iron boron) magnets are the most powerful permament magnets around. Try these, maybe: http://en.wikipedia.org/wiki/Magnetic_field http://en.wikipedia.org/wiki/Coulomb%27s_law Link to comment Share on other sites More sharing options...
YT2095 Posted May 23, 2005 Share Posted May 23, 2005 in the UK mains frequency is 50Hz' date=' I don't know if you could get to that frequency by hand only, so you may need a more industrial-style generator. [/quote'] no, 50hz is Very easy to obtain by hand even without the use of high gearing, a simple stepper motor of 200 per rev will output a good 500hz with a finger twist, so anything below that is childs play really Link to comment Share on other sites More sharing options...
5614 Posted May 23, 2005 Share Posted May 23, 2005 Oh, fair enough, a stepper motor, I meant litterally 'hands only'... but yes, a stepper motor would overcome the prob! Link to comment Share on other sites More sharing options...
calbiterol Posted May 23, 2005 Share Posted May 23, 2005 By the way, sorry - when I said email a mod, I meant private message a mod. Link to comment Share on other sites More sharing options...
Sarahisme Posted May 25, 2005 Author Share Posted May 25, 2005 ok , i accidently posted some stuff in another thread when i meant to post here....anyways this is the design of my generator... Link to comment Share on other sites More sharing options...
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