Help : High voltage input motorcycle battery charger

Discussion in 'General Electronics Chat' started by junang3, Aug 16, 2008.

  1. junang3

    Thread Starter New Member

    Aug 16, 2008
    4
    0
    Hi All,

    My motorcycle (400cc), when revving, the voltage reaches around 80V+ DC - bursted batteries and my regulator literally put my motorcyle on fire :) My solution as to not worry about replacing the regulator and battery ($90+) is to ride at around 40 kmh - but then again, when from stop (at first gear) sometimes revs up the motorcycle, eventually i'll have to carry a fire extenguisher or replace batt or regulator every so often :(

    Here's what i have done so far, bought two (2) 100v/60a KRPC3510 bridge rectifiers, since my alternator is 3phase, and there is no 3phase bridge rectifier locally available. That takes care of rectification.

    For the voltage regulation part I have questions :
    1. What would be the best regulator circuit that can handle 90v (or more) max continuous input voltage

    2. Since the primary function of the regulator is to charge the battery, does it need to be at more than 3A rating - when the motorcycle is running and all loads are on like lighting etc, will it draw more Amp from the regulator?


    Most of the circuits i have stumbled upon are from AC to DC high Amp circuits, voltage regulators but with less Amp rating ... i found one widerange regulator 100v attached, but local parts availability is a problem ...

    I have also looked at mechanical regulator of cars, but ... i wish i could understand more about it :)

    Thanks in advance ;) and best regards.

    Jun
     
  2. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
    1,438
    368
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Interesting page, Blocco - I found that using the Google translator makes it much easier for me to read, since I don't speak Russian:
    http://translate.google.com/transla...o-electro.interwave.ru/index.php?showtopic=10

    @Junang3: your regulator circuit definitely needs reparing. The regulator measures the voltage output of your alternator, and adjusts the current through the field windings to achieve the desired voltage level. In an automotive alternator, the output voltage is normally monitored after the 3-phase full-wave rectifier bridge.

    The problem with your regulator is either that the semiconductor which supplies the current to the field has shorted out, the voltage sense line to the output of the rectifier bridge is open, or the voltage level sensor in the regulator has failed. Another couple of possibilities are that the voltage sense line to the rectifier bridge is shorting to ground, or that a wire near the battery is shorting to ground.

    If you continue to operate the motorcycle without correcting this problem, it is very likely that you will burn out the alternator due to the excessive current. It was not designed to operate at such high voltage and current levels.
     
    Last edited: Aug 17, 2008
  4. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
    1,438
    368
    I think motorcycle alternators are usually permanent magnet, at least all mine were. I had a similar problem with a Suzuki that had a reputation for losing regulators and then blowing the electronic ignition. I went down the route of trying to make a regulator but gave up in the end as most of the prototypes went up in smoke. Eventually I replaced the regulator but added an over-voltage protection circuit to minimise the damage if it happened again.
     
  5. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Gee, that's strange - I wonder why they'd make them that way? :confused:
    Seems like a lot of power (torque) would be wasted at high RPM.
    That sounds like a decent plan. I'll bet the electronic ignition module was expensive. :eek: I was shocked at how much they wanted for parts for my motorcycle long after I bought it.

    Hard to say offhand what the current requirements would be for a mid-sized motorcycle. I'd guess somewhere between 15A and 35A. I bought a Kawasaki KZ650 many years ago (1980), but I sold it a decade ago - never had any problems with the alternator/generator; I never bothered to even look at the schematic for it since I never had to troubleshoot it. Just had to change the oil, set the points, and replace the battery every few years. Gave the buyer the factory repair manual when I sold it.

    Now that I'm thinking more about it - I'm wondering that if it DOES have field windings, whether an automotive-type regulator could be grafted in there. :confused: Sure would be cheaper than a motorcycle regulator - and much more plentiful. Our OP might pick up an alternator from a junkyard and take it apart to see how it works.
     
  6. junang3

    Thread Starter New Member

    Aug 16, 2008
    4
    0
    Many thanks Blocco, SgtWookie !!

    I felt the same frustration trying to find a good circuit to do - but to no avail, but burning cash frustrates me also :(
    Mine, Suzuki (!), has alternator with permanent magnets. Could have been nice if it used field windings - using a car electromechanical regulator would have been another option :)

    Thanks for the link, (and google!) the bottom schem seems feasible - 3 wires from the 3phase AC alternator, and 2 wires to battery - the same as my regulator.

    The main fuse of my motorcycle is 20A. So does it mean I need to have a regulator/rectifier that can supply 20A? and can handle up to 90V or more of AC?

    here's another link to a good 30A regulator, 12v30A as per the info, it can handle up to 24v, if the parts were available.

    The overvoltage would be in the AC lines?

    Thanks Again and best regards!
     
  7. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
    1,438
    368
    My favourite part of the google translation:

    "Field and transistor VT1 already serves as a safety valve in the very toilet tanks and nourishes the entire motorcycle." :D
     
  8. nazree

    Member

    Jun 23, 2008
    13
    0
    Are you sure it is the regulator that caused the problem?
     
  9. junang3

    Thread Starter New Member

    Aug 16, 2008
    4
    0
    Hahaha, i tried to also make sense of the translation, for the ratings and others, thanks to the schem diagram, datasheet and google:)

    @Nazree, have you had the same issue with your regulator?


    Best regards :)
     
  10. junang3

    Thread Starter New Member

    Aug 16, 2008
    4
    0
Loading...