Stators demystified

Discussion in 'Thumpers' started by Luke, Dec 17, 2006.

  1. Luke

    Luke GPoET&P

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    I would install it parallel to the battery. So + on the capacitor to + on the battery, - on the capacitor to - on the battery. You're describing a series connection which won't work at all.

    In retrospect, I probably shouldn't recommend it. It's not at all necessary for a working system, but I like the belt & suspenders approach. It's really best for cheap dual sport kit battery packs. Otherwise, just put your time and money into a better quality battery.
    #81
  2. huggybear

    huggybear Been here awhile

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    Thanks Luke
    I had just removed the capacitor and installed a ES4LBS battery on My WR400 with a Malcom Smith Dual Sport Kit and wasn't sure if I should hook the capacitor back up with the battery
    #82
  3. Seth S

    Seth S My avatar is ok. Your screen is broken

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    The other possibility is to lengthen your stator cover, flywheel, and add a second row of coils.....a little extreme perhaps.
    #83
  4. xtphreak

    xtphreak from B4 "adventure bikes" Supporter

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    what Luke is suggesting (holler at me if I'm wrong) is an AC filter setup.

    Capacitors don't pass DC, so putting it in series like you described will only allow current flow until the cap is charged up.

    Parallel as Like suggested is the same as cap + to battery + and cap - to ground ... what this does is provide an AC drain to ground for any neg pulse noise that gets past the rectifier.
    #84
  5. dirty_sanchez

    dirty_sanchez Dirty_Sanchez

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    I have the Electrosport ESG 950 hi output stator designed to be a plug and play unit for one of the big Yamaha 700CC 4wheelers. It mounts right up to the stator cover on my 640A feeding into a voltage regulator which is good for 450 watts off of a 950.

    I ran this setup on my '03 640A for a grand total of 10 minutes until I had a mechanical failure in the valvetrain so I can't speak for the reliability or longevity of the E'sport.

    I'd like to put this rig into an '07 640A.

    The hopped up stator is supposed to make another 100 to 150 watts than the stock 200w 640A stator. My main concern is the CDI, or black box.

    I do have a spare CDI that is known to be good, but what are the chances I burn up the CDI with the hot stator?

    Anyone think I could run a CDI out of the KTM 950?

    Dirty
    #85
  6. Luke

    Luke GPoET&P

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    It's probably fine. I would say certainly fine, but bad luck seems to follow that stator. The CDI feeds off the 12V from the battery, so as long as the voltage isn't high enough to cook the battery or blow out the headlights it will be fine. That's only going to happen if the 950 regulator gives up, and it's a tough one.

    It's unlikely the 950 CDI will work. Unless it happens to have the same crank angle pickup on the flywheel, and be happy with firing just a single cyninder instead of two.
    #86
  7. apullin

    apullin Adventurer

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    This is all really neat stuff. I'm actually in a class all about electromagnetic design here at Berkeley right now!

    Here's a pretty useful chart about motor configurations:
    http://www.gobrushless.com/kb/index.php?title=Winding_Chart

    GoBrushless also sells little motor kits for ~$30 if you want to experiment with winding up motors and how it works.

    I guess I should take the initiative and draw up some nice schematics for Wye and Delta wound motors of various poles and slots....


    Not to sidetrack too much, but couldn't the regulator be replaced with a step-down DC-DC converter to liberate more power?
    #87
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  8. 2strokefreak

    2strokefreak n00b

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    I beg your excuse but I have a problem with a WR450 that is able to start using the kickstart but show no spark while using the Electric starter... Any ideas

    I have use a new torque limiter.
    New coil
    New CDI unit
    change the Diodes
    etc.
    #88
  9. Dolly Sod

    Dolly Sod I want to do right, but not right now Supporter

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    Probably not a stator issue, you should start a new thread asking that question, you'll get more responses.
    #89
  10. tarzan30

    tarzan30 Been here awhile

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    Thanks for the writeup. I have been messing around with my current XR for a few months tring to get a good setup.

    History:
    rewond stock stator "after reading all your replies i think it is only one circuit in stator"
    stock wires coming up to regulator then CDI
    one more wire spliced in after the regulator "big red" going up to headlight for power.

    What i am trying to do and i think i have finally figure it out is.

    I have isolated all signals on the battery circuit. No ground.
    The regulator and headlight/brake are using frame as ground. "That would be my other AC side right?"
    If i wire in a full phase rectifier with the following config will it work?

    Big red AC regulated wire is the one power i have from the stator.
    Pin 1 on rec says ac
    pin 2 on rec says ac
    pin 3 on rec says +
    pin 4 on rec says -

    As long as i have no other DC grounds from my battery

    I should be able to

    Pin 1 from "big red"
    Pin 2 from frame
    pin 3 from + on batt
    pin 4 from - on batt

    I think that is how it should be ..... ... .. please tell me im right?

    Thanks in advance.

    T
    #90
  11. Luke

    Luke GPoET&P

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    Your connections look right, however if you are using the stock AC regulator and a regular bridge rectifier instead of a combination regulator/rectifier it probably won't work. I haven't done this myself, but a friend did and it didn't work. He was getting well over 35V on the DC side. He was using a capacitor on the DC side. If you use a battery I would expect it to work for a little while until the battery cooks.
    #91
  12. tarzan30

    tarzan30 Been here awhile

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    by regular bridge rectifier what do you mean? It is a full phase rectifier that according to my electric motor repair shop guy said .. " it will turn 12AC to 12DC"
    the part i bough from him is used in welders and is rated at 35amps. because i am getting a regulated AC at 13-14v should that not just go into DC if the connections are correct?

    Thanks for the help.
    #92
  13. Luke

    Luke GPoET&P

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    You have a regular bridge rectifier. It will work fine if you want to run a light bulb or heated grips or an electric motor off the DC, but will not work for a battery. The reason is that the average DC voltage will be near the 12V that you want but the peak voltage will be higher, and it's the peak voltage that will kill a battery.

    For utility power, the peak is around 1.4x the average value, so 170V peak for a 120VAC wall socket. On a bike it could be about anything- for my friend's XR600 it was around 35V peak at 13VAC.
    #93
  14. tarzan30

    tarzan30 Been here awhile

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    Im lost here.. thanks for sticking with me. When you are saying peak. would that not be unregulated? If i have a regulated AC circut that only gives me 12-14. how would it peak more than that? I though a regulator would take out any peaks?

    Thanks again.
    #94
  15. D K

    D K Been here awhile

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    Would there be any way to switch the wiring through a solenoid or a relay to go from Y (star) to delta with the engine running?

    Would there be any benefit?




    #95
  16. Luke

    Luke GPoET&P

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    Loads that are normally used on AC circuits don't really care about peak voltage over the short term, so the regulator doesn't need to limit them. A household light bulb is designed for an average voltage of 120. It sees a peak of 170V for a few milliseconds at a time, which is not long enough to damage it. If you connected it to a 120V battery it would work just like it normally does. If you connected it to a 170V battery it would burn out after a second or two. On a bike, the relationship between peak and average voltage is not as well defined as for utility power which is why I don't use it for an example.

    A DC regulator/rectifier is designed to limit the peak voltage because things connected to it often need to have the peak voltage limited. If there is no capacitor or battery -or a bad connection to them- the DC reg/rec can make the average voltage too low while correctly limiting the peak voltage.
    #96
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  17. Luke

    Luke GPoET&P

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    Yes. Just bring all six ends of the windings out of the case to relays which would automatically change the connections based on the engine speed. You could also have different windings on the same core and connect them in all kinds of ways. Instead of having one curve of output vs. rpm, you'd be able to take the best parts of several curves.

    It wouldn't be worth the complexity for me but it might be for someone else.
    #97
  18. elsalvadorklr

    elsalvadorklr southern xr rider

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    hey guys thanks for the awesome thread.
    Looking at my xr600 stator this is what I found, two wires, and a splooge of epoxy. How can I test it before rebuliding. Im in a middle of a re-build and looking at everything while parts come in.

    Pic:

    [​IMG]

    Thanks OP.
    Christian
    #98
  19. tarzan30

    tarzan30 Been here awhile

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    here is a discription of a AC regulator. This is why i am confused with what you are telling me.

    AC REGULATOR
    An electronic circuit used to maintain a level amount of voltage in an electrical line. It eliminates power surges, spikes and brownouts, which can cause harm to sensitive electronics. A voltage regulator "module" (VRM) is a voltage regulator in a replaceable unit. See surge suppression and UPS.

    I have seen from testing the stock AC reg that it does fluctuate like you say but only to a prediscribed limit. I am guessing the limit is 14v. That may not be what your telling me . If i am learning from you:D the voltage is not the peak your talking about it may be the current that will peak?


    Thanks again.
    #99
  20. Luke

    Luke GPoET&P

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    Take a look here: http://www.justxr.com/jaw/stator.html

    Measure the resistance of the exciter coil and the lighting coil. The exciter (the big lump of thin wire under the epoxy) should be between 230 and 320 ohms. If it's even a little higher than 320 I'd fix it. I'd guess the resistance of the lighting coil should less than 1 ohm.

    The exciter is the red and black wire, I think. Its other end is attached to the core so you need to have good clean contact between the core and the engine case.

    I'm just going off memory- I don't have the manual right now, so double check everything I've said.