MOSFET voltage regulator/rectifiers

Discussion in 'Motorbike Technical Discussion' started by User Bp, Aug 12, 2014.

  1. User Bp

    User Bp Guest

    The RR on my '01 sv650s seems to be on the way out.
    Shindengen's fh008 seems to be a popular replacement
    and are said to run much cooler that the SCR style.

    New units don't seem available, but
    has an fh002 which seems promising. However, I can't
    find specs. It's rumored to be a 25 amp unit, which
    would work.

    If anybody's been through this drill before I'd be
    grateful for your insights.

    Thanks for reading,

    bob prohaska
    User Bp, Aug 12, 2014
    1. Advertisements

  2. User Bp

    Mark Olson Guest

    The components of most any three-wire permanent magnet motorcycle
    alternator are pretty much interchangeable, electrically. Do the
    connectors on the FH002 match the ones in the SV wiring harness? If
    so, it should plug and play, otherwise you'll need to get out the
    crimping tool and heat shrink.

    The website says the FH002 fits Honda CBR600,
    CBR900/954/929, CBR1100XX. Unless those all have significantly weaker
    alternators than the SV I can't see how it wouldn't work.

    25A should be fine, I doubt the stock SV650 stator puts out much more
    than 20A.

    PS it's still probably a shunt regulator (they make MOSFET series
    style, too) but the voltage drop across the FETs is lower than an SCR
    so it dissipates less power when shorting the windings for regulation.
    Mark Olson, Aug 12, 2014
    1. Advertisements

  3. User Bp

    User Bp Guest

    No expectation of plug and p[l,r]ay, I have a power take off splice
    that will require re-terminating the RR anyway. The more I think of
    it the better the experiment seems.
    That's consistent with my thinking.
    The manual rates the generator at 300 watts, but they don't state
    a nominal voltage. It's implausible the current is more than 25 amps.
    I'm very unclear on the shunt-vs-series tradeoff. Shunt regulation maximizes
    copper loss, but series regulation takes the core material through its entire
    magnetization curve, maximizing iron loss. The voltage isn't a problem, but
    hysteresis in the iron might be, depending on how the designer balanced the
    losses. With enough copper shunt might be more efficient, an excess of iron
    would favor series regulation. Most likely the optimization was for cost,
    it's not obvious where that puts matters. Thanks for reading,

    bob prohaska
    User Bp, Aug 13, 2014
  4. User Bp

    Mark Olson Guest

    The wattage figures I have seen usually at calculated at 14V or so,
    which is a reasonable battery charging voltage, so about 21A max.
    Magnetics were never my strong suit ("I understand some of those words")
    and I opted to skip all the power and rotating machines stuff... but my
    guess is that even using an ideal switch with zero resistance, the stator
    isn't going to overheat, compared to how it would function with the stock
    SCR-style shunt regulator.
    Mark Olson, Aug 13, 2014
  5. User Bp

    User Bp Guest

    Agreed entirely. The order to Mad Hornets is in, let's see what happens.

    Thanks for reading!

    bob prohaska
    User Bp, Aug 14, 2014
  6. User Bp

    User Bp Guest

    In case anybody's curious, the Mad Hornets order arrived in
    six days (from China) by USPS. To that extent I'm impressed.

    The regulator delivered bears a "YHC" logo in addition to the
    Shindengen-like part number FH002 4.0 251 and the Shindengen
    trademark (two inverse-series diodes in a circle).

    Hooked up to my VFR800 it worked reasonably. It got warmish, but
    certainly no worse than the OEM RR. The worrisome thing was that
    most of the heat seemed to emanate from a very small area under
    the part number markings. In that small area it was too hot to
    touch comfortably after a few minutes' idling. Regulating voltage
    was around 13.7 on a Shorai LiPO4 battery, rising to just shy of
    14 when revved. That's low, but it usually takes a while to peak
    and given the heat I didn't want to run it that long.

    Granted, the test is a little unfair. The FH002 is said to be a
    25 amp unit, the VFR alternator is a 34 amp device. It seems worth
    intalling in the SVS with a 24 amp alternator to see if the heating
    is more manageable.

    Whether this is really a Shindengen FH002 MOSFET regulator, a licensed
    copy, an unlicensed copy or a conventional SCR regulator sporting a
    more attractive part number remains unclear.

    Thanks for reading,

    bob prohaska
    User Bp, Aug 24, 2014
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.