Single Phase Voltage regulator is Shunt.

Discussion in 'Electrical' started by Hoople, Oct 18, 2011.

  1. Hoople

    Hoople Account Removed

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    Here is some info for those of you that may find it interesting to see what's inside the sealed black box single phase voltage regulator. The business end of the regulator is made up of 6 beefy semi conductors. These are what do 99% of the work, generate 99% of the heat and probably go bad 75% (my guess) of the time. These are the components you are testing with the service manual meter tests (bleed back test etc).

    The interesting thing to note is that the single phase regulators are in-fact shunt regulators (see shunt semi's S4035's clamping stator) but the late model 3 phase regulators are not. Surprisingly my 2009 service manual has a mistake which says my 3 phase regulator is "shunt" when it is not.
    Also note that not 1 single integrated circuit was used in the complete design. All discrete components.

    Also note (schematic) the dangerous issues that "could" arise if you happen to be running short of good luck. Almost any combo of failed semi's will always result in a dead short across your stator.
    No wonder they go out in pairs!

    My Thanks goes out to TQuentin1 for boxing up,,shipping & supplying me with a pair of DOA single phase Genuine HD regulators as organ donors. Thank you TQ!
     

    Attached Files:

  2. Jack Klarich

    Jack Klarich Expert Member

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    Very interesting good job on dissecting and very good write up:s
     
  3. Mavagrand

    Mavagrand Senior Member

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    Hoop, can you explain the difference between single phase and three phase? which is better? I thought my 08 FLHTC had a 3 phase.
     
  4. Hoople

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    For an alternator to charge a battery, it's output has to be GREATER than the battery's voltage. In a single phase system, there is a large portion of time when the alternator output voltage is less than the battery voltage. Therefore, during a large portion of crankshaft rotational degrees, the battery is not actually being charged. (the gaps in voltage can not be seen using a standard handheld volt meter. The meter sees the output as a constant charging voltage but it is not)

    A 3 phase system overcomes that issue. Instead it has 3 single phase systems that overlap each other just at the right time. Just as the 1st phase goes below battery voltage, the next one takes over. When 1 phase is not above battery voltage, the next one steps in.
    The huge advantage of a 3 phase system is that it can supply charging current at a lower RPM. So at idle or low RPM, the battery has a better chance of getting charged.

    It is easy to tell which type you have by looking at the stator leads coming out of the primary cover. 2 wires is single phase and having 3 wires means it is 3 phase.
     
  5. geezer

    geezer Senior Member Contributor

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    Great info Hoop, Thanks. :)
     
  6. Iceman24

    Iceman24 Well-Known Member

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    You were shocked too many times as a child...:s

    Great stuff Hoop - keep the knowledge & electrons flowing..!!
     
  7. Mavagrand

    Mavagrand Senior Member

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    Thanks, Hoop!
     
  8. R_W_B

    R_W_B Senior Member

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    Wow a post from Hoople that doesn't go right over my head. I feel good. Thanks for these very enlightening aspects.

    Hoop is the 3 phase one 120 degrees out of phase on each leg like in buiding wiring ?

    And does the single phase one still have 2 legs 120 degrees out like building wiring or is it actually just one stator winding literally ?

    I promise not to ask any more questions, would like to know the above though.

    I know the single phase voltage on my home for a two pole (2 bus) breaker rated at 220 volts it averages between the two buses (phase legs) at around 208 volts on a meter with the push and pull.
     
  9. Hoople

    Hoople Account Removed

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    Don't know how your coming up with those numbers (208 volts)? Be careful when using the word "average" around AC voltages because the "average" voltage of a sine wave is actually zero.


    Yes, 0, 120 & 240. It is called 3 phase (and it is) but it winds up being much more than just 3 phase per engine revolution due to the number of magnets used in the rotor. Each time you clock just 1 magnet past 1 stator flux concentrator, you generate 3 phases of 1 complete 360 cycle. So the total number of phases actually generated for EACH engine revolution can be 18 to 27.

    The Single phase system is two leg with no center tap (neutral) which is rectified by a full wave bridge (picture 4 above).
     
  10. R_W_B

    R_W_B Senior Member

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    Oh ok thanks for all the answers and info.

    As to your question, all I know is this electrican buddy of mine used to say that the single phase 220v system could only produce (in reality) about 208 voltage. Since during a short part of the revolution the 2 phases overlap and both legs would be traveling against each other (for a short time) and some of the potential would cancel out. Now that I think about it he used the term "vector" not average, so my error on the wording. A vector is more a trig respresentation of the two phases and is not an average.

    And I should not have said "on the meter" in that context since I was not talking about a multimeter but rather the power meter out on the wall that tells how many kwatt hrs are being purchased.

    Plus I've actually seen written references of the 110/208 single phase as opposed to writing it 110/220.

    But I went out just now and put a testor across my two bus bars in the garage and it read 239 and 120 on one bar to ground. So must not be much power consumption with the nice weather. On days with there is a lot of consumption they will roll it back and I've measured 220 and 110 respectively.

    But thanks for the info, it was enlightening to see how the bike stuff correlates.