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]

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.. :2thumbsup might have to look at doin that that with my toy!!! :Punk:

Jen :rockon:

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

[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 :yes:

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...*:eek5:

[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.

[xwhatsit]

Hey man, I thought many times about a SMPS design too. Don't know why they're not used -- plenty of off-the-shelf parts available to do it.

I won't ask `why', because I hate it when I want to do something (e.g. my battery-less ignition) and people ask `why'. Because you can, of course. So I won't ask you, I'll just offer an alternative. The CB250RSs, CX500s, and maybe CBX250s (if so it'll definitely work with yours, I'm sure) had an excellent regulator, big heat-sink with lots of fins. They never blow up, apparently -- lots of guys with later model Hondas and Suzukis which have shit-house over-heating reg/recs buy them and retrofit them.

I've got such a thing in my boxes of spares. $40 and you can have it, I wouldn't normally ask for money, but I might need to buy a new one one day (as I am running a capacitor instead of a battery, who knows what might happen). Alternatively, there's heaps of them on eBay for not much more. Model number SH232.

[davereid]

Hi Rob, I'm not really sure what you mean when you say you have an AC generator rather than an alternator.

But heres an explanation of how it all works.. it will either inspire you, or put you to sleep.

An alternator and a generator both work the same way - wires are pushed through a magnetic field by the rotation of the engine.

Sometimes the magnetic field is created by fixed magnets, sometimes electromagnets (The field winding) is used. This is the same for alternators and generators too.

An alternator will produce AC electricity, which is rectified externally using semiconductor diodes. A generator also produces AC, but by a cunning arrangement of switches attached to the generator, the polarity of the AC is changed every 180 degrees. This gives you rectified AC directly - no external rectification is required. Generators were developed first, as the diode was not invented, so a mechanical system was the only way to go.

So, once rectified, you have a kind of DC - suitable for battery charging.

Voltage regulation.
The two main factors that control how much energy you are making with the wire you push through a magnetic field are (a) how strong the magnetic field is, and (b) how fast you push the wire through.

So, to control the output of your alternator (or generator) you have lots of methods. You could run it via a gearbox. And as the engine speed changed you could use the gears to speed up or slow down your alternator to change the output. I've never seen this done, but perhaps somewhere in Russia...

Or you could reduce the strength of the magnetic field. This is very common, and very easy if you have electromagnets creating your magnetic field. You just turn em off, and presto, job done.

But most motorcycles use fixed magnets. So the faster the engine goes, the more energy you produce, and an external regulator is required.

The series regulator simply disconnects the alternator from the battery when voltage gets too high. It works OK, but has a couple of problems. Firstly you have to be able to switch the entire full load current of your alternator. This requires quite big switches. Secondly, the ouput voltage of the alternator will get very high. As there is no current, there is no heat, but you have to build a very good alternator to withstand the high voltage that you might reach.

The shunt regulator works by diverting excess energy to heat. Effectively, a circuit is designed which simply detects battery voltage. As battery voltage gets too high, the circuit puts a load (like a resistor) across the battery. This resistor gets hot, but keeps system voltage in check.

Electronically its a very simple circuit, and vey cheap to make. It has a few drawbacks, and its regulation is not really that flash, but in practice, it works very very well.

Hope this helps !

[SOHC]

Decided to move REG REC to front of frame on down tube from head stock.

It's hanging in the breeze....

next mod is to actually solder and heat shrink the wires to prevent useless connections...

Rob.

[TripleZee Dyno]

Decided to move REG REC to front of frame on down tube from head stock.

It's hanging in the breeze....

next mod is to actually solder and heat shrink the wires to prevent useless connections...

Rob.
A simple solution to a simple problem.
Complex solutions for simple problems are reserved for situations where someone else is paying the bill