Regulator Rebuild

[emry]

Using a full wave reg/rec should work just fine, one diode leg just would never be used (it could be a spare). As long as the wattage rating is greater than the Guzzi orginal. I will play around at work and see if if I can find either a full wave reg/rec that might work and/or a 3 phase. Give me few days.

 

Does anyone have the output spec handy?

[Tom M]

Using a full wave reg/rec should work just fine, one diode leg just would never be used (it could be a spare). As long as the wattage rating is greater than the Guzzi orginal. I will play around at work and see if if I can find either a full wave reg/rec that might work and/or a 3 phase. Give me few days.

 

Does anyone have the output spec handy?

 

The spec for the Ducati Energia OEM unit from Euro Motoelectrics says 32 amp/450 watts.

http://www.euromotoelectrics.com/category_s/27.htm?searching=Y&sort=13&cat=27&show=20&page=1&brand=Moto%20Guzzi%2C%20Ducati%2C%20Laverda

 

They also have an Enduralast unit that's made by Ducati Energia that says 14.2 volts/450 Watt.

http://www.euromotoelectrics.com/product_p/edl450-voltrect.htm

 

The Guzzi repair manual says "The regulator has been calibrated to maintain the battery voltage between 14 - 14.6 volts.". My assumption (probably wrong) is we should be seeing 14 volts somewhat above idle and 14.6 at high rpm. Is anybody out there with the stock regulator seeing more than 14.2 volts?

[raz]

The Yamaha (& Suzuki) regulator operates by shorting out the alternator coils when the battery is up to voltage

The Guzzi regulator operates by opening the circuit when the battery is up to voltage.

I'm curious, why do they short the alternator? Doesn't that mean the alternator will steal half a horsepower from the engine even though battery is fully charged, whereas the Guzzi one will just act like a flywheel?

[Kiwi_Roy]

I'm curious, why do they short the alternator? Doesn't that mean the alternator will steal half a horsepower from the engine even though battery is fully charged, whereas the Guzzi one will just act like a flywheel?

I guess it's easier with a 3 phase alternator since 3 phase is allways putting out current and you need the current to pass through zero for an SCR to turn off. I tested my Guzzi out of curiosity I think I got something like 27 Amps AC shorted out. Perhaps shorting out doesn't consume as much power, I'll have to think about that, I saw 27 Amps but no Volts (no Watts). The 27 Amps will certainly heat up the coils.

[Cliff]

Shorting generators/motors is what you do when you want to brake so there must be more happening then just shorting.

[Kiwi_Roy]

Today, the Sport groaned a bit on the start up. That's not happened since I found the broken yellow wire under the alternator cover.

 

Oh, no! Another played regulator? Flinky earthing, again?

 

vDC at idle: 12.5, vDC at 5k: 13.38. Not good.

 

I put the Hawker on the 2 amp charger and it gradually increased its charge from about 12.4 (not good) to about 13.3.

 

I then *flashed* the AGM with a 10 amp charge until it reached 15.5 vDC (took three to five minutes), and followed up with a 2amp charge until the battery would hold 14.92 (45 minutes to an hour).

 

Now, the idle voltage is 13.10, and the voltage at rpm is 13.61.

 

I must be letting my AGM battery get soft. I remember Hubert speaking of this before. . .

[Kiwi_Roy]

This might be a good spot to start a side topic on repairing the regulator.

Here are a few pictures taken in the process

 

The epoxy is quite easy to remove, you just need patience. I would describe it as a bit like sugary toffee to cut through

Once you have the board exposed you need to unsolder the diodes and SCRs

[Kiwi_Roy]

The trickiest part of the process is removing the circuit board. You need to slice all around and under as much as possible using the grommet location to poke the knife under.

 

The first picture shows the board finally out

 

The second picture shows typical arcing, the diode lead is just soldered on. Im not sure what causes the solder to melt, probably an overload then it starts to arc away. With one diode not properly functioning that's probably when you notice the charging seems to be weak.

[emry]

When using a "open" (SCR is used to open the current path) style recitifier voltage can only be regulated in half waves. For the regulator to function the SCR's must be turned on, they will remain in this state until the voltage crosses 0v, at which point they will open, thus cutting output. This can make output filtering very important as voltage levels can swing wildly at low frequencies.

 

A "short" sytle regualtor will ground a circuit at a determined voltage level, instead of cutting out a half wave it will only remove a portion of the output during that cycle (normally this voltage level is measured post filter, thus the short can actually occur at any point during the full recification cycle). This helps to create a much more stable voltage output, particularly when used with 3-phase. This method is much more electronic friendly as it creates much less noise (electrical, not audible).

 

Open styles are cheap, short styles get more expensive. In the short sytle SCR's, IGBT's or FET's are used depending on requirements and cost. IGBT's and FET models will actually clip (by shorting the circuit at a higher frequency than the a/c) the voltage to a determined level thus smoothing the output even more. This can be very desireable with modern elctronics.

 

Short sytles also are desireable because of less chance of stator or reg/rec arcing. When a permanent magnet stator circuit is open, full voltage is still produced, this can lead to arcing which will flow full current (though a non-desired path) and melt, the up side is the rectifier does not deal will constant high current loads, once again cheaper because less attention to heat dissaption is needed. A short style will drop the a/c to a lower value because of the reduced impedence, which lowers the chance of arcing, although the recifier and regulator now must be able to dissipate more heat, airflow and construction can be a concern.

 

Hope that makes sense.

[luhbo]

This might be a good spot to start a side topic ...

 

At least this is a very good spot to thank you for sharing these informations. I guess I did forget this the last time I had the oportunity

 

Hubert

[Kiwi_Roy]

 

Hope that makes sense.

Makes perfect sense to me, of course I'm easy

Actually I posted it on an electrical forum I use all the time.

This guy is a guru. What he says is it's producing current without producing power. The current still heats up the circuit but it takes little HP to produce it. When it's charging the battery it's using more HP, you'll have to trust me on that.

 

Skogsgurra (Electrical) 22 Jul 10 11:53

The impedance is mainly inductive so the shorting produces reactive current, which doesn't heat much, nor does it load the prime mover. Shorting with triacs is still used. At least in trial bikes. That's where I have seen it.

Heres the charging circuit from my 2005 Suzuki S50, I have seen others similar

[Kiwi_Roy]

OOOppps the server crashed, i hope it wasn't me

 

The next picture shows the board right out. Inside the case at lower right you can see the two SCRs, these are the other half of the bridge. To the right of the diodes what looks like a tack is a diode lead that came off, the other diodes lead is still attached to the circuit board on the right hand side (it's flipped over) The transistor is missing in the middle of the board, although not attached to the case it wants to stay behind. You can also see a burnt out resistor on bottom edge of the board, that drives the charging light. I suspect the lamp was shorted out at some time. A couple of parts got destroyed in the process but they are readily available.

 

Picture 2 shows a good pair of diodes alongside the pair I just took out. Actually the second pair is repairable, just needs cleaning up and soldering back together.

[Kiwi_Roy]

And here's the circuit diagram

Emry said "When using a "open" (SCR is used to open the current path) style recitifier voltage can only be regulated in half waves. For the regulator to function the SCR's must be turned on, they will remain in this state until the voltage crosses 0v, at which point they will open, thus cutting output. This can make output filtering very important as voltage levels can swing wildly at low frequencies"

You can see this on the right hand side the waveforms are what I saw with my scope, really lumpy eh!

Regulator Schematic.pdf

[docc]

I've renamed the thread to describe the topic as it has developed. I've no way to rename the subtopic, so we're stuck with *shocking difference.*

 

Now I wish I had saved my old, fried regulator (I usually save everything). I'd guess my reg/rec is an arcing mess as described. One more contributor to my Guzzichondria . . .

 

Whacking the charge voltage to 15.5 really did wake up my Hawker, which is otherwise probably on its last dying electron.

 

Time's tickin' , yah?

[docc]

Groaning crank over again this am in spite of the long ride yesterday. What do you suppose is a reasonable service life for the regulator and for the Hawker Odyssey? I'm thinking five years (+/- 6 months) for each would be "normal."