Stator Output? NGC

[Canuck750]

I have a question for our Guzzi electrical experts (calling Kiwi Roy?)
My 1978 Moto Morini 500 has been converted to a battery / coil Electonik Sasche ignition and the Stator was rewound in the Uk. The Stator has five coils for charging and one for the old ignition, I have deleted the old ignition coil, just the five interconnected charging coils for the battery , lights etc. The rewind shop left two wires out of the charging coils to connect to the reg/rec.
attaching a multi-meter to the two wires from the Stator I get a reading of appx 40 bolts AC with the bike running at appx 4000 rpm.
When I go for a couple hour ride the battery has drained down to about 10 volts, not enough juice for the electric starter and the LED signal lights just flash very fast but dim.
So it appears I am not getting enough of a charge to the battery.
The reg/rec is a modern replacement from Ricks Moto electrical, simple unit used on ducati bevel twins amongst many others. Out of the reg/rec is a pair of red wires that goes to the battery positive.

My question: is 40 volts AC a good value for output from the stator into the reg/rec?
What voltage DC should I be getting out of the reg/rec?
Is there a simple test I can run on the solid state reg/rec to confirm it’s operating properly?

Thanks
Jim

[Chuck in Indiana]

I'm certainly no sparky, and KR will Shirley be along.. but..

My question: is 40 volts AC a good value for output from the stator into the reg/rec?

Yes. The RR should output around 14.3 I think.

[Old Jock]

Agree with Chuck, these figure sound about right.

I know nothing about the RR does it only have 4 wires, 2 from the stator coils and 2 that connect to the battery?

I suppose that Voltage sensing could be from the battery wires and all earthing internal.

Stupid question but is the RR grounded well and little to no resistance between RR ground and battery neg?

I'm thinking if the Rectifier was floating it might not be seeing true system volts and allowing the system to charge.

One more thing after a ride is the RR hot?

I'm ASS-uming it's a permanent magnet alternator

These are all just wild guesses, hopefully Roy will pop in soon

[Canuck750]

Agree with Chuck, these figure sound about right.

I know nothing about the RR does it only have 4 wires, 2 from the stator coils and 2 that connect to the battery?

I suppose that Voltage sensing could be from the battery wires and all earthing internal.

Stupid question but is the RR grounded well and little to no resistance between RR ground and battery neg?

I'm thinking if the Rectifier was floating it might not be seeing true system volts and allowing the system to charge.

One more thing after a ride is the RR hot?

I'm ASS-uming it's a permanent magnet alternator

These are all just wild guesses, hopefully Roy will pop in soon

The Reg/Rec has two yellow wires (connects to the two wires from the charging coils of the stator - AC voltage will climb as high as 50 V AC when I rev the motor up)

There are two red wires from the Reg/Rec, the instructions said to join these and connect to battery.

There was also a black wire and a white wire, I was told to ground the black wire and tape off the white wire.



I removed the red wires to the battery and ran a multimeter DC volts and get nothing at idle or revving up the bike, there is no output coming from the Reg/Rec. The unit is a year old and its dead.

What causes a Reg/rec to die?

[bigbikerrick]

Heat? They are a big "heat sink". I would think any location that limited the air stream to the RR , could be detrimental to its long life.
Rick D.

[Old Jock]

If it's well grounded, then that's about all I've got

I agree with bigbikerrick heat can kill them as he said they need airflow, that's why they have the fins, that said some OEMs put them in stupid places (looking at you Ducati)

Within reason you can use other acessories to drain the excess current (heat) headlight for instance. Otherwise the RR has to reject all the heat, as the output from the Alternator will be fixed for a given RPM

Sorry Canuck but you really need Roy to give you more detailed info, but it's looking like the RR is defective

John

[huub]

Dont run a morini with the battery disconnected,
The bike will start, but you can easily blow the regulator if you rev it.

on my morini's i use a shindengen  mosfet regulator ( SH 640e-11) , works great.
cheap knockoffs are easily available on ebay/aliexpress etc

[Paul_Tim]

You didn't say (or I missed it) but did you check the DC voltage across the battery with the RR connected and the engine running? If you dont have approx 14V then the battery is not charging irrespective of what you have comming out of the alternator. You may have a faulty RR or it's connected incorrectly      I'm not familiar with the parts you have so can't help more than that.
Good luck in finding the problem.

[Wayne Orwig]

With a permanent magnet alternator, the AC voltage is somewhat irrelevant. It of course needs to be well above the battery voltage.
The rectifier will of course limit the voltage at the stator to the battery voltage. If there is no regulator then the load needs to perfectly match the coil current, or the voltage will climb too high.
The coils are operated in saturation full time. A lot of regulators are shunt regulators. As in, they just short out the coils to regulate the voltage. Since the stator is in saturation, the coil current and heat doesn't really go up much.
But, that does mean that if the battery wire or such is open, there is no place for that current to go and the 12 volts may head towards that 40VAC before the regulator gets a chance to limit it, and you might damage something. Maybe. Maybe not. Depends on the regulator.

[Canuck750]

Dont run a morini with the battery disconnected,
The bike will start, but you can easily blow the regulator if you rev it.

on my morini's i use a shindengen  mosfet regulator ( SH 640e-11) , works great.
cheap knockoffs are easily available on ebay/aliexpress etc

I am going to order one of these units from Roadster Cycle - Jack Fleming
Roadstercycle.com

With the bike running I only get 11.5 volts across the battery terminals, nothing come out of the reg/rec to charge the battery.

[Old Jock]

I don't know the 640 but Shindengen RRs are fantastic pieces of kit, although pricey and you'll be getting a genuine one from Roadster.

Jack should know if it's suitable as many of them are 3 phase but can be used with a single phase alternator, it appears that the Morini is single phase.

Good choice IMHO

[Canuck750]

I don't know the 640 but Shindengen RRs are fantastic pieces of kit, although pricey and you'll be getting a genuine one from Roadster.

Jack should know if it's suitable as many of them are 3 phase but can be used with a single phase alternator, it appears that the Morini is single phase.

Good choice IMHO

Jack told me the unit will work with the two wire single phase Moto Morini system. He told me he has sold them for Ducati 860 bikes with basically the same Ducati Electronic ignition.

[moto-uno]

  This may be of some interest , throughout the late 70's and into the 80's H-D used VERY similar
regulator,rectifier assemblies . 2 ac inputs and a single 12 volt output , hell I even used them in
British bikes back then , just removed the zener diode and reversed the battery to -ve ground  .
They tend to be reasonably priced . Peter

[Canuck750]

  This may be of some interest , throughout the late 70's and into the 80's H-D used VERY similar
regulator,rectifier assemblies . 2 ac inputs and a single 12 volt output , hell I even used them in
British bikes back then , just removed the zener diode and reversed the battery to -ve ground  .
They tend to be reasonably priced . Peter

Thanks for the tip Peter. I am going to look into that.