Blew my LED headlight

[NorazDad]

Hey Guys,
I blew my LED headlight on my 81'H and replaced it with a Halogen. I did install a permanent volt meter recently to help monitor my charging issues. HHB PMA and R/R were not charging for a while and then it did. In the discussion of going all LED with a PMA I thought I would use this as chance to see if a regular 55w headlight would help prevent over charging...Well the volt meter with the LED hung right at 14+ volts at 3000+, but with the Halogen, the meter is not going above 12 volts.
Needless to say, I reordered a new LED, but I am confused about the charging issue. Also for discussion purposes, I have been thinking about going with a Mosfet, but now I am not sure. Everything was working/charging just fine. I know there are those who dislike the PMA because of it's potential to send too much current to the system if the R/R can't handle it, but everything had been working just fine. R/R cool to the touch after a ride and not overheating at the stator, etc.
So chime in if you would like.

 

[jamesgs4]

do the mosfet. I switched after burning up 3 from HHB. I got a japanese made shindengen from ebay.
http://www.ebay.com/itm/380705241034?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:
I also went through 2 LED headlight setups, but they were made in china units so I wasn't expecting much from them.
As a note, the HHB units worked fine around town. It was only on long trips (2000-2500 miles) where I was running at freeway speeds all day did the parts fail.

 

[NorazDad]

Nice to know. Thanks. That's what I needed to know.

 

[retiredgentleman]

Noraz........................LED's are very rugged. How did you manage to blow it? The voltage must have gone quite high. Do you know what the voltage was before the LED blew? What did you pay for the first LED and now how much did you pay for the second LED?

Running a PMA and LEDs sure seems like a very expensive way to go. You paid for the original PMA/rec/reg, 2 LED headlights,
1 halogen bulb, and now considering a Shindengen rec/reg @ $118 USD. What's the total cost when you add this all up?

Your PMA and Rec/reg unit are not working at all , if you only see 12 volts with a halogen 55 watt and engine at 3000 rpm.

 

[NorazDad]

Well Yeah, that's the problem. The LED didn't actually blow, it just sort of went dim then when I turned the power on it flashed and then went dim. It worked intermittently for a while, then it didn't.
As for the Reg/Rec, I have been having issues with it/them since I installed the PMA. Hugh and I exchanged three, until I got a jump from a friend and then suddenly it started to work and has been working fine since. In fact, I installed the volt meter at your suggestion and it has been very comforting to see exactly how much juice is running through my system. As for expense, well
Dew
LED Motorcycle Headlight Bulb H4 COB Moto Headlamp with Cooling Fan DC9-100V 20W Hi/Lo Beam Lights for KTM BMW Suzuki Yamaha Kawasaki Honda Scooter (Pack of 1)
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This is what I ordered.
When I install it, I will check the voltage again and see if things return to normal. I still think I am going to get the mosfet eventually.
I don't consider any of these items extreme. New pipes however...
Thanks for the response.
I'll post a follow up.

 

[retiredgentleman]

If you want to use a 20 watt LED headlight, you should use the stock alternator and stock type rectifier and regulator. The stock system has the ability to reduce its output to more closely match the low current draw of the LED.

If you want to use a PMA system , then use a 55 watt halogen headlight. The PMA will generate 200 watts at 4000 rpm, so you need to consume as much of that power as possible.

 

[NorazDad]

Yeah, that's what I thought, but my volt meter is saying otherwise. I will have to check the PMA output today and make a decision. I know how you feel about the stock alternator and R/R, but for the time being this is what I have and will continue to use. Maybe this winter I'll reinvestigate the stock system. I still have it and I could get it up to snuff. We will see.

 

[retiredgentleman]

If you are testing the PMA output, you should monitor the voltage with the engine up around 3800 to 4000 rpm, which is a more typical rpm when driving down the road.

 

[Grimly]

Found this out the hard way through owning GS Suzukis for quarter of a century.
The PMA system works well, but the regulators of them belong in the Stone Age, until recently, when Shindengen brought out the Series Reg/Rec, which handles the regulation differently.
Basically, the older style (the one that Suzuki fitted, the ones that Caltric, et al supply) are still of the old style and what they do is dump unused current back down through the generator windings. The user trick there is to use as much of that output current as you can, to avoid too much excess being shunted back downwards - which only adds to the heat in the windings.
The newer Series design has taken advantage of modern control electronics and successfully interrupts current flow in its tracks, without having to dump it back down. In other words, if you need it for a headlamp, and ignition system, it supplies it, and stops at that. The result is the alternator windings run much cooler and live far longer.
Shindengen Series Reg/Recs were fitted to a series of Polaris RZR 400/800 ATVs for the past several years, and it seems that Shindengen may have been using them as a test vehicle for these, before launching a new, larger version onto the bike market.
Fwiw, the Polaris version is widely available, is cheap and reliable and will not fail. More importantly, it will not cook your stator.
Even better, the used Polaris R-Rs are available for under $40, but make sure you get a genuine one - there are a few fakes around.
If in any doubt, look for the SH-775 part number on the end of the unit, and if you see a suspiciously clean-looking item saying it's a replacement or direct equivalent of the Polaris one, then beware - it's 99% sure it's not a Series, it's a fake (actually a cheap and nasty MOSFET masquerading as a Series).
MOSFETS were once the solution, but they've been out-classed by the Series design.

 

[NorazDad]

Wow, that is the most comprehensive explanation of shunt vs series RR I have ever seen. Thanks, Dude. I will continue the research and see if I can find an SH-775 series unit.
Peace Dude!

 

[Brew]

I've been having similar issues with my pma swap. burned up 3 batteries so far. I'm going to add an inline 15 amp fuse coming off my shindegren positive to try and solve this. I may just keep getting bad batteries because this last go around the battery cooked but the regulator still works. go thread!

 

[dps650rider]

So, just to be clear on this the stock regulator shunts excess current to ground to maintain the correct voltage. The Shindengen regulator is a high efficiency switching voltage regulator much like what is used in many power supplies for electronics?

 

[retiredgentleman]

quote:
"So, just to be clear on this the stock regulator shunts excess current to ground to maintain the correct voltage."
You better study up on how the stock alternator and stock regulator work. There is no excess current with the stock system. The stock system only produces the current that the load requires, which is why they work so well.

The PMA is the design that has problems with excess current, that burns up regulators, stators, and ignition systems.

 

[retiredgentleman]

I've been having similar issues with my pma swap. burned up 3 batteries so far. I'm going to add an inline 15 amp fuse coming off my shindegren positive to try and solve this. I may just keep getting bad batteries because this last go around the battery cooked but the regulator still works. go thread!

Adding a 15 amp fuse will not help you with burning up batteries. If you are burning up batteries, that means the batteries are being over charged. Your electrical system is likely unbalanced. The PMA is producing too much wattage, which the bike is not consuming. Your regulator is unable to control the voltage; the voltage goes high and cooks the battery. If the battery is too small it only makes things worse.

If you use a stock type charging system, which is always balanced, you would not have any of these problems.

 

[Brew]

i just spent all this money to upgrade and you're telling me me to switch back. I'd rather try and make it work some how. I know lots of people do this "upgrade" and make it work...

 

[Grimly]

So, just to be clear on this the stock regulator shunts excess current to ground to maintain the correct voltage. The Shindengen regulator is a high efficiency switching voltage regulator much like what is used in many power supplies for electronics?

Nearly - not quite Not to ground, but in that general concept of ground being a place to dump stuff.

The shunt (stock r/r on a PMA) puts the excess currnent back down through the windings of the stator - it's a 3-phase stator and there's always one on the way back down, that can be jammed full of surplus electrons just to get rid of them for a brief time. Only drawback with that is the stator ends up having to deal with not just the engine heat, and the heat of actually generating power, but the extra heat of this shunted power. You can see why those poor little windings eventually turn their toes up.
What the Series reg does is recognise the load that's actually being drawn by the bike (headlamp, ignition, etc) and just let that through (there are no microprocessor smarts as far as I know, just pretty well designed voltage sensitive circuitry). The current flow is stopped, momentarily, then restarted again a microsecond later. You'd never know this was going on, all you're aware of is a cooler stator, a longer-lasting battery, a better charge voltage and a brighter headlight.

The BIG problem with the shunt design was the electronics of the day were'nt up to the rigours of Series operation, but they could act as shunt switches, so that's what Suzuki did. They lasted well enough - well, until the bike was in its second or third owner, and out of warranty, and that's all that counted.


FWIW, I'm running a stock Electrical Field Controlled standard generator and have no problems with it. If it goes belly-up I'd consider a PMA, but only allied with what I know about Series reg/recs. It would still be a toss-up between that and a standard system, with works well when maintained properly and is the exact same system as was fitted, Mostly trouble-free, to millions upon millions of cars for decades.
With modern LED lighting the old field coil generator has much less strain on it, and it can run a shit-hot headlamp, too, without reaching its limits.

 

[retiredgentleman]

i just spent all this money to upgrade and you're telling me me to switch back. I'd rather try and make it work some how. I know lots of people do this "upgrade" and make it work...

A PMA is not an upgrade. IMHO its a downgrade. The stock japanese charging system used high quality parts (Hitachi), and is a better design than a PMA. The stock system works the same way as your car or truck. It has the ability to adjust to different loads. The stock system is always balanced.

The Chinese PMA systems use poor quality parts and is quite often unbalanced. Too much wattage is produced and the bike may not be able to consume it. Voltage goes high when the regulator can't control the surplus current. That's why you have batteries, regulators and stators over heating and failing.

 

[dps650rider]

The stock system may be a better design but with one exception, it requires brushes which wear out and can cause the alternator to quit at very opportune times. Been there done that more than once.

IMO, a PMA with a high efficiency switching regulator would eliminate this weakness.

 

[retiredgentleman]

Brushes in the alternator are a wear item, just like brake pads. As part of regular maintenance, you check the wear and replace as required, before they wear out. I find brushes last about 16,000 kms or 10,000 miles.

 

[dps650rider]

I swapped out to a PMA a couple years ago and have had no issues. However, after learning that most regulators are simple shunt regulators I am considering replacing it with a series regulator. I suppose that the first clue was the size of the heat sink on the regulator, an efficient unit would not be required to dissipate that much power as heat.

What is the best source for one of these, the link in one of the previous posts?

BTW, I bought my bike new and ran the stock alternator for about 120,000 miles. In that time I did the following
* Replaced countless brushes
* Replaced a failed rotor
* Replaced a failed rectifier
* Had the stator fail, at this point I installed a PMA