need help with motorcycle Regulator

[hizzo3]

ok here is the issue. Motorcycles suffer from stator failures. I believe that most of this "wear" on the stator comes from the regulator. Here is why i think so. They are a shunt style regulator. This means the stator is always producing maximum power, and what isn't used it burned up as heat. Very ineffcient and makes for short stator life. Now unlike in cars where they adjust the strength of the magnet coils in the alternator, we have a permanet magnet. I know of someone who is currently using SCR's to attempt to switch on and off the current. Works, but not very well as it cant turn it off in mid cycle, only at the end. PWM has also been tried, but with the variable incoming voltage/current it doesnt work very well. i read somewhere that you can use a current regulator in line with the current, but are there any units that will handle this much power? is it efficent? will it reduce the stator load?

here is what the stator produces. 16-140 volts ac (which is then rectified) and 4-40 amps. It is a 3 phase system.

Any ideas?

 

[Russlk]

What kind of motorcycle is it? I have had Triumph and BSA motorcycles that ran for years with a zener diode regulator. Perhaps what you need is a better motorcycle.

 

[The Mad Professor]

Zener regulator ! how fortunate !!
I recall an old Honda RS 200 from my youth that used only a relay and a shunt resistor. After struggling to start with the lights dim and the engine labouring a swift smack of the hand to side panel and the beast startled into life, lights ablaze , engine revving furiously like a stallion startled by its first taste of spurs. Damm thing nearly killed me on more than one occasion as hitting a pot hole in the road often unsettled the relay contacts.

 

[hizzo3]

I have an '04 kawasaki vulcan 750. great bike with lots of power on tap from the engine. its shaft driven with hydrolic lifters means very little mantinace. The big issue is that to cut cost, the manufature use lower quality wire which has a bad habit of shorting out now, and the regulator is a full wave rectifier/with a shunt style regulator. I love this bike and would love to keep riding it, but every one complains about the 8000 to 12000 miles we get out of a stator, when other bikes can pull almost 60k outta one. I'm already gonna use some high end magnet wire (200deg c insulation) but now i am gonna need a bigger regulator since i am gonna boost the amp output (sorry i couldn't deal with the fact if i hit my brake lights or if radiator fan came on my headlight dimmed). when i do a search, all i can find are shunt style regulators. surely there has to be a better more efficent way. Even when considering i am bout to boost the stator output by 20-30% in amps and 10% in volts (has a big drain at idle that lasts up untill 2500 rpm redline is 7500).

 

[Russlk]

Replacing the wires is a good idea, but boosting the voltage and current will run into a problem: More voltage means more turns and more current means larger wire, but the manufacturer has filled up the space with the wire already, so are you going to design and build a larger stator?

 

[hizzo3]

there is about 1/4 inch space at the bottom of the poles and almost 1/2 inch at the top before they touch. so i have a good amount of room to work with.

 

[sazerac99us]

For a quick fix on the headlight, try a headlight relay...very cheap, brighter lights and will extend the life of your headlight switch..whether or not you re-engineer the altenator, I'd go that route anyway. Sounds like an awful lot of trouble though, to fix this problem, unless you can sell your updated version to other disgruntled Vulcan owners.
Ride Safe

 

[Russlk]

Yes, connecting the headlight direct to the battery, using a relay, should solve the dimming problem. Also, vacuum impregnating the stator with varnish should prevent the wires from moving and causing shorts.

 

[hizzo3]

I've already got a headlight relay. The primary issue is that the charging system is only producing about 9 vdc and 8 amps at idle. This means the battery is filling in the gap. Considering i have a 14 amp hr battery, this is tiny when your biggest draw is at a stop light or in traffic. This is why i am rewinding the stator to produce more at idle. At a stop i have 55 watts headlight, 56 watts in my tail light, 28 in a turn signal+8 more in the indicator light. (keep in mind this is blinking so it is surging and so on like any other incadesant light), another 60-80 in my radiator fan. and of course the draws of an ignition module. 188-208 watts draw (blinker at 50% duty) at idle at a red light before the ignition takes what it needs.

Boosting the stator output isnt that big of an issue. its reducing the heat it produces at 4500 rpm (this is crusing engine speed @70mph) b/c the regulator is almost in a full shunt grounding out all the excess voltage and current. That is why i wanted to see if i can make a different type of regulator. Just to give you an idea, the stator produces about 80 vac at this speed. so its gotta ground out to about 26 vac. that is 54 volts that is being shunted out.

 

[Russlk]

The problem is, the series regulator will need at least 1 volt to operate and the output voltage needs to be 13.8 volts to keep the battery charged. That means the 9 volts needs to be boosted to 14.8 volts from the stator. The high end also gets boosted, from 80 volts to 132 volts. The max current is 12 amps, so the power dissapation is (132-13.8)*12 = 1435 watts. This power will be divided between the stator and regulator, depending on the stator resistance. The load is only 166 watts, so the system is very inefficient. I expect the stator resistance is high, to limit the current, and contributes to the low stator life.

 

[sazerac99us]

I'd think about a new bike...Triumph makes very good ones these days (not just prejudice because i ride one though)

 

[hizzo3]

well i would love to get a bmw but considering i paid less then $3k for this bike, i cant complain too much. And with gas sitting at $3/gal and my jeep getting 19 mpg's my bikes 55 mpg looks so much better.

Yeah i wish they could have built an alternator system in. I would design and install it myself, but the engine revs too high (7500 is red line and limiter kicks in at 8k rpm) and would destroy the comunicator. I would have to gear down the rotor, but it cant be done cheaply as it is mounted on the crankshaft.

yeah i cant believe how much this system is burning off. When i rewind the stator, the low voltage at idle should jump to about 10-11 ish. a booster circut wont be needed. its getting rid of the excess 80 volts when it is up at 7k rpm. Someone i am in touch with is using SCR's and having them turn on when the voltage is just right in the cycle. The issue he has run into is the current isnt high enough. Since the voltage is already in AC, how effect would a step down transformer be?

another idea i had was in the stator. how hard would it be to "double" wind the stator in this fasion. When at idle, it is in a Y configuration, and when voltage jumps lets say over 30 volts, it then changes to a delta? This i assume would be done by the regulator.

Or this configuration. each pole would have 2 sets of windings. when the voltage rises over 30 volts, it starts alternating between the windings? this would decrease the amount of voltage seen, and lower temps. how would the current run? I know the voltage is related to the turns, and current to the gauge of the wire. would it drop?

 

[chilinski]

There has been a huge discussion of stator/RR issues on the Delphi Suzuki forum (https://forums.delphiforums.com/RLCMC/start). Some people are ditching the OEM RR for one made by Cycle Electric for HD (the CE-602), which is a series device to replace the stock shunt type. Preliminary reports are that the switch is a good thing. The common thread seems to be that the shunt RR drives the stator at full power 100% of the time and that eventually leads to stator failiure.

I will know more shortly. My stator died on a trip to Penn State recently, and it had to be jumped at every stop on the return home. Right now, parts are all on backorder, so I ride only short distances and charge my battery after every ride.

I don't know if the Suzuki forum is the best place to get info, but here certainly is a lot of info there.

 

[bountyhunter]

I've already got a headlight relay. The primary issue is that the charging system is only producing about 9 vdc and 8 amps at idle. This means the battery is filling in the gap. Considering i have a 14 amp hr battery, this is tiny when your biggest draw is at a stop light or in traffic. This is why i am rewinding the stator .

Are you sure you didn't blow one of the rectifiers? If you have a three-phase system, you would still get some charging but at reduced current. I guarantee you your system is not working as originally designed if your system voltage drops to 9V at idle. You could also have a bad battery. With headlight on, bikes (and cars) do run a little current from the battery at idle but your battery should never drop to 9V under a 8A load or else it is hosed. It should stay up at about 10V under starter crank which is WAYYYY more than an 8A load.

Before you try to rewind and redesign, you might want to see what needs fixing?

 

[MikeMl]

How about using the existing stator, and then using a switch-mode boost switching regulator to regulate the system voltage? You could probably get much higher efficiencies that way.

Honda does this with their gas-powered generators. They use a switching converter to make 60Hz 120VAC out of an alternator which produces anywhere from a few Hz to over a hundred Hz, where the alternator voltage varies all over the place. They only run the gas engine faster as more electrical load is added. You don't care about the frequency, but you could use a SMPS for the regulation.

 

[Mr RB]

Juts buy one of the Cycle Electric ones. I said that on the other regulator thread. They will work with just about any AC stator, and put out a nice 13.8v DC AND stator and regulator will run pretty cold from then on.

Any type of shunt SCR regulator is just barbaric on a modern high current low resistance perm magnet alternator.

 

[bountyhunter]

Any type of shunt SCR regulator is just barbaric on a modern high current low resistance perm magnet alternator.

It is definitely wasteful, but that's what most motorcycle's run.

On the upside, modern bikes have all the lights "hard wired on" (there's no more switch to turn on/off the lights) so the shunt doesn't have to work so hard since it has a pretty big load on the system all the time eating up most of the alternator current.

 

[Nigel Goodwin]

It is definitely wasteful, but that's what most motorcycle's run.

And no other option really with a permanent magnet.

 

[Mr RB]

Sure there is. That's the thing about the Cycle Electric type, they are a disconnect type using a high volts FET rated for the 100v or so that the alternators put out when open circuited.

The old shunt to ground regulators worked ok on the old type alternators, these had weak permanent magnets and high resistance windings with lots of turns. It was ok to short them as regulation.

The newer alternators tend to have very powerful permanent magnets, very low turns of wire and good magnetic effciencies so shorting them to ground is very nasty. I run the cycle electric type on my old harleys and have never lost another alternator. The stock harley (and aftermarket) shunt regs kill the regulator and/or alternator VERY often.