Jump to content

Recommended Posts

 Any electrical engineers on TT? I've been thinking about having my lighting coil rewound to set up the lighting system for 12 volts.  I have a couple extra lighting coils so If I could just give the coil frame to a rewind guy, he could put the correct gauge of wire on it to give me 12v.- after a rectifier/regulator does it's job.  SO, the question the rewinder will ask me is what gauge and how many turns. For a higher voltage, you need more windings.  That's the way coils work.  More turns equals more voltage.  So, I'm thinking if I just tell him to go 1 gauge smaller (or maybe 2?) than the OE coil and just fill up the OE frame until it's the same coil o.d. so it will still fit in it's position on the stator plate.  I've seen guys rewind a coil and it's not that hard if you have the jig/machine to just securely hold and turn the frame as the wire is fed, even by hand.  I don't even need to tell them how many turns, just make the OD the same.  I'm just not sure what gauge to specify...Anyone got any hints?

Share this post


Link to post
Share on other sites

Do you know how many amps you want available for your electrical system? You should try to get a number in mind. You could go down one or two steps in gauge size but I wouldn't suggest any further than that. If you go too small in gauge size the wire will become resistive in the circuit. Figure up your actual current need and multiply by 1.5. Look at the data sheets of what ever wire you like and make sure it is rated for that amount of current. Dishes are done. Amps = watts/volts.

Share this post


Link to post
Share on other sites

well, it will be a 12 v. system after the rect/reg. so I guess I should decide what wattage I'd want for the headlight.  Tail light is an LED and is a very low current item.  BTW-I was an electronics tech for WAY too long so I'm familiar with ohms law. Maybe I should go from the other way and check out headlights, them go backwards from there.

Share this post


Link to post
Share on other sites

not knowing anything about electricity except for that you must complete the circuit I once rewound my lighting coil on  94 WR 250.   Upon close examination I realized that there was a lot of room under the flywheel so I unwound the coil counting the wraps. then rewrapped with the next thickest gauge magnet wire the same number of wraps , test fir  and then slowly unwrapped until clearance was good.  was off  maybe 20  30 wraps  compared to 500   or so>(forget actual numbers).  If I remember correctly from what I was trying to read at the time  as the magnet saturates the wire you will only get so much wattage, so if you add more wraps your voltage will increase but available amperage drops. Trying to get more wire  with lass wraps  was my thought.   semi successful in that with a lead acid vide0 camera battery and full D.O.T. lighting  the battery would maintain its voltage in full dual sport mode(slow city riding turn signals and brake lights as need ed with low beam on.  if the battery was low at idle you could see the headlight pulse  it would pulse fairly bright with each rpm  but never had enough to recharge the battery and the turnsignals or brake would knock it down quite a bit.  If I kept the bike (kick myself in the ass for getting rid of it )  I would of ventured into  leds  and probably could of saved a good percentage of energy

Share this post


Link to post
Share on other sites

ps

 

 I forgot that as unwound the coil  I realized that you can stack more plates on the (base?) of the coil makin it slightly taller before I wrapped  also used a full wave reg/rec    nut even sure  whether or not I improved anything.........  If I remember correctly  had the main bearing go south taking out the stator plate.   Bought a new wr stator plate(at that time  the wr stator with the lighting coil was actually cheaper than the yz new from Yamaha).  while toying the idea of dualsporting the bike  upon repairs   IFRC  the Yamaha lighting coil couldn't keep up  the special wrap 50w aftermarkets did better  and my homemade one  would love to think I did a lot better but probably more than self pride clouding results   but I do remember I would not want hand unwind while counting and hand rewind while counting   ever again.       A little Elmers glue   worked pretty good on helping each layer of coil stay in place

 

Share this post


Link to post
Share on other sites

Thats why I'd be totally willing unwrap what's there, then start winding until I've basically equaled the old coil OD.  kind of an experiment but there are things I don't NEED to know like what the max current of a specific gauge of wire is because I'll never be taxing that bad.  CURRENT is what melts wire and putting out more voltage - because of more windings - the current will be less.  It's true that the wire gauge will be a size or 2 smaller but those wires take a LOT of current before they fry.  If you look on you tube, there are several videos that the guys made their own jigs to hold whatever coil form they have but with a cycle, it's such a weird shape, it would be hard to make a holder to hold both ends.  A couple guys used a variable speed drill running slowly on the driven end of their coil form.

Share this post


Link to post
Share on other sites
15 hours ago, Chuck. said:

You can buy ready to go rewound stator from Ricky's and others.

Here is a thread by a EE on stator rewinding. http://advrider.com/index.php?threads/stators-demystified.189734/

And I've converted 6volt Honda stators to 12 volts by using a 12 volt regulator & 12 volt bulbs.

Thanks Chuck!  That advrider post was quite a write-up.  The Honda you converted - Did you do any other changes or just the regulator and obviously the bulbs?  I have a sneaking suspicion that would work with the Suzuki.

Share this post


Link to post
Share on other sites

So, it looks like my original thought - to go with more turns on the coil was WRONG according to that post linked to by Chuck. .  I have a coil removed that was from a donor bike and this coil was cooked.  I don't have any idea what caused that.  Doesn't matter. At least I could measure the wire gauge.  I think I'm going to try about 2 gauges larger  -which isn't much, only a few thousandths larger - and less turns on the coil form.  I already unwound it and counted the turns, although that number probably isn't a huge deal. It was 330 turns of 23 ga. wire.

Edited by motoxvet

Share this post


Link to post
Share on other sites

Current capacity of wire is based on the cross section area and for American Wire Gage (AWG) every 3 gauge decrease doubles the wire cross sectional area. Metric wire gauge is related to the wire's diameter so the numbers go opposite AWG or SAE. And SAE wire gauge has about 10% less capacity of the same AWG size.

  • Like 1

Share this post


Link to post
Share on other sites

I was thinking of going with #21 AWG.  A nice increase but not ridiculous.  Now, I just have to figure out some way to hold the coil frame so I can feed the wire as it turns.  I'll have to look at some more You tube videos and get more ideas.  Also for a WAG for number of turns I should do, I was thinking 260 to 270.

Share this post


Link to post
Share on other sites

I would do the 330 turns  and then unwind as needed.   using the elmers glue in the wraps will help hold it together  and will peel off easily if you need to.   once you get the coils you need  smear the coils with a good epoxy to hold it together and prevent chafing within itself.

 

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×