Mosfet Regulators

[mcgovern61]

I would like to start a thread regarding mosfet regulators that can be a one-stop and shop location to gather all of the information we have for easy reference.

I would like input from all to answer the following questions:

Does the mosfet regulator have a real world advantage?

1100 stators last a very long time with the stock regulator if the wiring and connections are maintained in good working order. Will reducing its load help that?

Does a mosfet prevents stator failure?

At CGW, we love gadgets and improving when possible, but does the advantage justify the cost for a mosfet?

 

[KYWinger]

+1

 

[dan filipi]

There's some talk that a mosfet controls voltage better than a OEM regulator.
Has anyone had problems with OEM voltage making a mosfet regulator worth the cost?
From my 10+ years reading about GW stators and regulators, makes me think not.

Far as I know the only real advantage with a mosfet is it may help the stator last longer because it's not working as hard and will run cooler but ONLY if the continual load demand on the stator is reduced by use of low wattage bulbs (LED).
A mosfet in no way increases the stator wattage output.

 

[KYWinger]

dan filipi » Mon Jan 13, 2014 9:11 am[/url]":1hdwrxtx]
Far as I know the only real advantage with a mosfet is it may help the stator last longer because it's not working as hard and will run cooler

I believe that as well - it shuts off the stator when not called upon; cooler operation and longer life are two probable results.
Those who've done it also report a better, more constant voltage at lower rpm's.

 

[joedrum]

well if all this is true .. it has mpg gains too ... if you think a full output stator all the time dosnt reqire power ... crank up a generator and apply load ... im sure the power is somewhat small ... but its all the pull the stator can mustard all the time in the stock set up ......very wasteful set up ... if you going to make power it needs to be used not wasted

 

[AApple]

From what I've gathered reading about this deal, the MOSFET regulator is just that...it regulates the amount of juice the stator puts out to the system, depending on demand of the system. In the stock system, the stator is always "On", and whatever is not needed for the system is shunted to ground, which creates a lot of heat. The Mosfet reg would switch the stator output on/off as needed, and not send anything to ground just for the heck of it. Seems to me that would be an advantage across the board, as far as heat building up in the stator, the reg/rectifier, AND the wiring/connectors. Plus, as Joe mentioned, it's bound to help some with engine load at idle speeds....maybe not a lot, but it has to help some.
I also would agree with it being most beneficial with a lightened electrical load by using LEDs, and getting rid of the coffee makers, heated seats, and microwave ovens, since the more load the system has on it, the less effective an On/Off type regulator would be, since it would more likely be in "On" mode more often than "Off" mode....at least at idle, or slow speeds.
This is one mod I might actually do in the future, since imo, it is worthwhile, at least on paper. My background is automotive, and all automotive systems have on/off type regulators, but they also have alternators that put out more juice to start with. Bike electrics are a different animal to me, so I may be way off the reservation on this, but it certainly sounds like a good deal. :wave:

 

[dan filipi]

joedrum » Mon Jan 13, 2014 9:27 am[/url]":2el9fc7t]
well if all this is true .. it has mpg gains too ... if you think a full output stator all the time dosnt reqire power ... crank up a generator and apply load ... im sure the power is somewhat small ... but its all the pull the stator can mustard all the time in the stock set up ......very wasteful set up ... if you going to make power it needs to be used not wasted

Good point Joe.
My external alternator slows my idle down when I turn on the 2- 55 watt driving lights and there's a definate slower rev when they are on while the engine has that extra load on the alternator.

One burning question I have is the rattling I hear in my engine.
I'm thinkin because the stator load isn't there, that's allowing the drive for it to clank around inside.

 

[ekvh]

Due to the design, can the power be switched on and off by a regulator? Can the input be modified to meet the demand? I was kind of thinking this was an all or nothing stator. I know not.

 

[dan filipi]

ekvh » Mon Jan 13, 2014 10:40 am[/url]":3582eh80]
Due to the design, can the power be switched on and off by a regulator? Can the input be modified to meet the demand? I was kind of thinking this was an all or nothing stator. I know not.

One way to know for sure is someone do this mod and check ac amps on the yellow wires before and after.

 

[joedrum]

id say everthing runs on battery and the regulator deals with battery ... one thing for sure when a circuit is not complete no flow no heat and no pull regardless of how it works

 

[backlander]

I haven't seen anything in the system that allows the stator to be switched on or off. The stator produces AC power from the time the rotor starts spinning around the stator until the rotor stops. Think about it, only power leads, 3 yellow, come from the stator up to the reg/rec, there are no direct grounds to any phase of the stator to attempt to shut it down, which would in effect be the same as a break in the windings causing the stator to fry. IMHO. The mofset just does a better, cooler job of bleeding off the excess voltage not needed at any one particular time. It's interesting though. The only way to turn the stator off would be to break down the magnetic field produced which would require electro magnets in the rotor that could be switched on or off breaking down the ability of the stator to produce power and that's just not the way the GL system is built.

 

[ekvh]

I just found this explanation of why a Mosfet might be better.......or worse. This was from Thumpertalk:

The way the R/R holds the voltage down on the bike (with the standard Suzuki R/R) is the let the load of the bike pull the stator down initially. Think of a resistor divder network only the first resistor is the stators coil resistance and the final resitance is the load from the bike. If the stator is pushing out 70V ac then when rectified that'll be 35V pulsed DC - which is too much for the bikes electrics. If the load of the bike and battery (it's effective resistance) is equal to the stator coil resistance then the voltage at the stator will be halfed (17.5v dc pulses). That effectively means that half of the power is being dropped in the stator coil and the other half is being dropped over the bike - in both instancanse this is primarily being converted to heat. If you could increase the load (reduce the resistance) of the bike you can pull the stator voltage down even more. By switching on heated grips or a head light you just might pull the stator down to 14 volts at your cruising revs so the R/R has no need to trigger the Thyristors - all is good and power is being dropped evenly.

Okay..., so say you have a fully charged battery and no lights on - the output voltage of the stator will be trying to climb too high, in which case the controller in the R/R will trigger the Thyristors. The thyristors are either OFF or On. When ON they will striaght short the stator back to itself (for the positive going pulses). They are much lower resistance than the stator so the stator will be the generator and it's own load, effectively dropping almost all the power from the positive pulses across itself.
Hence it would be better to drop the power across your heated grips &/or headlight rather than let the R/R deal with it for you.
The only draw back is if you switch on too many loads you'll start to not charge your battery at lower revs, but that is the nature of the system...
A good plan might be to make sure evrything is switched on when cruising at high speed but knock all the extra off when around town, stopping for light etc. or you might flattern your battery.
Also make sure you have good earth connection and good wiring or all the extra equipment use will not actually pull more from your stator, it'll just flatten your battery - see Free Power Mod.

The MOSFET system is better as it doesn't short the stator against itself, it switches OFF the negative going half of the output - thus reducing the output by 50%. This would mean for 1/2 a cycle no current flows and that coil would actually get chance to cool.
The only problem I can see with that system is that it would allow the voltage in the stator to soar to full. This in istself could weaken the stator as it weakens the insulation of the coil windings. It's not too bad though as it's just 35v'ish compared to 14.4v with the Suzuki regulator, and I suspect more stators fail from over heating than insulation break down due to running at full open circuit voltage.

Have I made any sense?

 

[backlander]

Probably a whole lot more than I did Eric, I think I'm totally lost on this deal and will crawl back into my corner and assume a fetal position. :smilie_happy: :smilie_happy: :wave:

 

[Ansimp]

backlander » Tue Jan 14, 2014 5:58 am[/url]":11kv6op3]
I haven't seen anything in the system that allows the stator to be switched on or off. The stator produces AC power from the time the rotor starts spinning around the stator until the rotor stops. Think about it, only power leads, 3 yellow, come from the stator up to the reg/rec, there are no direct grounds to any phase of the stator to attempt to shut it down, which would in effect be the same as a break in the windings causing the stator to fry. IMHO. The mofset just does a better, cooler job of bleeding off the excess voltage not needed at any one particular time. It's interesting though. The only way to turn the stator off would be to break down the magnetic field produced which would require electro magnets in the rotor that could be switched on or off breaking down the ability of the stator to produce power and that's just not the way the GL system is built.

You must have a circuit for an electrical load. The ac component of the alternator ( rotor inside a stator) does not have anywhere to go with a switched ( Mofset) R/R if there isn't any load.

Most motorcycle R/R are waste type as the charging circuits are normally quite small so most of the time full output is required.

 

[ekvh]

Hey Backlander!!! you're squeezing me! I'm already in that corner. Just to clarify, I copied that. I am as confused as ever about them.

 

[dan filipi]

Yeah when the explanations start getting into theory and technical jargon I back away too.
Our corner is getting pretty cramped :smilie_happy:

Give me a bike with a working stock charging system.
I'll check voltages and current before and after installing a mosfet. That I can understand.

 

[Ansimp]

dan filipi » Tue Jan 14, 2014 7:29 am[/url]":yzgzwes2]
Give me a bike with a working stock charging system.
I'll check voltages and current before and after installing a mosfet. That I can understand.

One of the reasons I didn't install my Mofset regulator in the Rats Nest, but did have it as a spare in case of a failure. I would only recommend this change if you are unhappy with your charging circuit or just want to do an upgrade.

I personally would not chop out the stator plug on my bikes, I would just replace it with another modular 3pin plug but that is my trade. If I didn't have that option I would solder the wires together as shown by others but I would always want the plug to allow easy diagnosis of the charging system.

 

[dan filipi]

I did a few searches on mosfet regulator design and how they work.
It became very obvious there is no simple answer.

 

[K7TKA]

I've been reading along with you guys and understand the confusion. Let me try explaining by using a heater as an example. A mosfet will switch very fast so if you are heating a tank of water to a specific temperature of say 100 degrees with a 1000 watt heater and a mosfet controller the heater will be on full time until the sensor detects the temperature is getting close to 100 degrees. The mosfet will then start shutting off and on which will slow the temperature rise. When it gets to the setting it will be off most of the time but will cycle the heater to maintain the temperature. It is the ability of a mosfet to switch rapidly that makes it all work. Now substitute a battery for the water tank and a stator for the heater and maybe it will make sense.

Good Luck

 

[joedrum]

its down to weather you trust the switching device or stock set up feed to ground ...hmmmmm