Regulator/rectifier project....

[SOHC]

Hey everyone.

I am thinking about making a new REG/REC for my bike.

I have a gb250 with a AC GENERATOR. Which sucks but hey, an ALTERNATOR would have been my choice but no...

So I am thinking that when my reg/rec blows (which it will) I would like to replace it with something that:

A. Handles current
B. is attached to a HEAT SINK with a FAN.
C. is not hidden under the seat getting HOT with no air circulation...

So I guess if anyone out the has INFO or CLUES as to a good schematic or diagram, you could point us in the right direction.

I am thinking that it's not too much of a drama to make, have some experience etc

Plans are thin on the ground.

and I reckon that X amount of $ for the same crap is a waste of time and money.

I mean DIODES are CHEAP! and you can get mega grunty ones too! Hey you only need SIX for a three phase set up.

I am not sure how many bike use three phase stators and REG/REC but I know that a few do.

Catch my line of thinking?

Rob.

[pete376403]

The stator papers, at http://thegsresources.com/garage/gs_statorfacts.htm will tell you more than you ever wanted to know about alternators, regulators and rectifiers.
And most bikes have a 3 phase alternator.
With my GS1100 I extended the wiring to the regulator/rectifier and mounted it under the steering head where it gets a nice cooling draught - works fine

[jonbuoy]

Rob google SOHC forum, you can rig up two Jaycar AC bridge rectifiers thats what I've done. There is also a regulator circuit on that website do a search. Got a picture of your bike?

[MyGSXF:Me]

With my GS1100 I extended the wiring to the regulator/rectifier and mounted it under the steering head where it gets a nice cooling draught - works fine

Good thinking.. might have to look at doin that that with my toy!!!

Jen

ps: know anything about "bridge recitfiers"??? apparantly one of them would be useful on my bike also..

[jonbuoy]

Bridge rectifiers...

[rogson]

Check out http://regulatorrectifier.com/

They claim their stuff is higher quality than OEM and it doesn't seem overly expensive.

Anyone bought anything from them?

[terbang]

Keep yer battery well serviced, and all will be fine. I have adapted GN250 R/R's to my GS's in the past they are more heavily finned and seem to work well. Apparently the honda products are good too.

[xwhatsit]

Apparently the honda products are good too.

The early Honda ones, at least -- the modern ones with next to no fins are piss-poor in terms of longevity, apparently.

A good candidate is the CX500 reg/rec; I thought my own reg/rec had popped. I started to do some research to replace it, and a large number of sources said to get a CX500 reg/rec. It turned out my own one wasn't stuffed at all -- and anyway, the CB250RS uses a CX500 reg/rec anyway

Probably about $40 off eBay?

Build your own, though, much more fun.

[Swoop]

Apparently the honda products are good too.

*spurts drink over the computer whilst trying not to laugh...*

[bimotabob]

Hi

Don't waste your time making one, try a wrecker as some big honda's have large heatsink reg/rects that I'm told are all good to use.
(you can adapt any 3 phase type so you can pick and choose)
If you want new Eurobike sell several H/D Shindengen types to suit all configs - some of these are very good.

Cheers

[Bonez]

Hey everyone.

I am thinking about making a new REG/REC for my bike.

I have a gb250 with a AC GENERATOR. Which sucks but hey, an ALTERNATOR would have been my choice but no...

So I am thinking that when my reg/rec blows (which it will)

You may be waiting a long time for the GBs reg/rec to blow if you look after it.

[SOHC]

ha!

Found one.

http://www.takisnet.org/~abayko/appnotes/vreg.pdf

it's sooooooooo simple.

SCR's are cool.

R.

[davereid]

I'd be cautious building that circuit.

It regulates all right, but it does it by shorting the alternator to earth. That means the energy being created by the alternator is being sunk as heat, into the alternator windings. It will eventually fry your alternator stator.

You could build a similar circuit that used the SCR as a series component instead of a shunt component. So the SCR would normally be off.

You would turn it ON any time the voltage dropped below say 13.5 volts.

So, at the higher voltage you are attempting to regulate, by leaving the SCRs OFF there will be no current flow. There will also be no heat.

You could replace the rectifiers in the circuit with SCRs and simply turn the rectifier ON when you need more volts, thus eliminating all the diodes.

While this would work, electrically it is very noisy. And real SCRs are not perfect, they don't switch instantly, so they actually will still get quite hot.

The manufacturers like SHUNT regulators. But they put them AFTER the rectifier. Yes, like the man said, they short the battery.. but as they are set to commence shorting at 13.8 volts, the battery will never reach this voltage on its own. So the shunt regulator actually only has to deal with the energy that the motorcycle is generating in excess of its requirements.

Say you have an alternator that is good for 200w at 10,000 rpm.

Headlight = 55w
Ignition system = 40w
Battery charging = 20w
Tail lamps = 10w
misc others = 2w average
TOTAL = 127w

So your shunt regulator only has to deal with a relatively modest 75w.

Of course, as you slow down, the output of the alternator will drop. At 5000 rpm on the highway, it may only be good for 150w, and 120-130 at city speeds.

[davereid]

ha!
Found one.
http://www.takisnet.org/~abayko/appnotes/vreg.pdf
it's sooooooooo simple.
SCR's are cool.
R.

Stop press - forgot to point out that if you use a shunt regulator, and put a battery charger on, while the battery is still in the bike, the shunt regulator will attemp to regulate the charger. This is actually a very common cause of regulator failure on small engines.

Battery chargers that put out less than 13.5v or are only of 2-3A capacity are safest choice on small engines - particularly in cases where you want to keep the battery topped up.

[SOHC]

hi Davereid

Good thinking.

I still am not sure how REAL reg/rec's work anyway but it seem that shorting out the windings on the stator seemed a bit strange. Why not just turn them off?
how about some kind of switchmode reg?

I really would like to understand how the system works. I got stuck at school on phasor diagrams curent and voltage being out of phase and then every thing went dark...

Grr. I must understand.

Why not just put a god damn alternator in there? FFS it's not that much of a drama.

Rob.