Topic: Reg/rectifier question

[Mtmooradian]

Can I use one from a newer sport bike? I have a parts kawasaki 636.

[Dyrden]

Generally no.  Modern bikes have a different type of charging system.

[Mtmooradian]

Why wouldn't a rec/reg from another 3phase charging system work? If it just needs to drop the bottom of the wave?

[Don R]

There is a good article in proven tips and tricks. explains it all.

[GammaFlat]

My opinion (which is an opinion ) is to use the old regulator.  You'll have a very difficult time (don't know of anyone who's done it yet) doing a better job.  You're into issues with shunt regulators heating up your alternator - most non-Honda solutions are "shunt" type.  In terms of the rectifier, build your own.  There are several threads that cover it on this site.  The rectifier has room for improvement both in robustness and efficiency whereas the regulator is hard to beat.  Also, be sure to use new connectors from sites mentioned in those same threads. 

If your regulator is misbehaving, it likely easily fixable and if you don't want to tackle it, I believe HondaMan will do it for you.  He's a great guy doing great things to great bikes for great prices  (another opinion ). 

[TwoTired]

Why wouldn't a rec/reg from another 3phase charging system work? If it just needs to drop the bottom of the wave?

If "modern" means a permanent magnet alternator, then those reg/rec, won't be able to control the electrically excited alternators used on the SOHC4.
The output of the SOHC4 alternator is controlled by an electromagnet whose strength is determined by the voltage drive from the regulator.

Permanent magnet alternators, even if three phase, have no control input for the magnet strength, so the regulator doesn't provide for one.

[Mtmooradian]

Ok so let me get this straight
bike needs juice- Regulator sends signal to alt... Powers up magnets(like in most car alt) then alt makes three phase power(ac) then rectifier lobs the bottom off leaves you with dc....... So could I use the reg out of a 12v car alt and any straight rectifier?

[Mtmooradian]

Like this nx250 rectifier

[CycleRanger]

This is the thread for you.
http://forums.sohc4.net/index.php?topic=12465.0

[GammaFlat]

You can use a Ford pickup truck regulator (part number is in PinHead's thread) but it acts as a "shunt" regulator instead of controlling how much you "excite" your alternator like the regulator from Honda (those guys were smart).  The shunt regulator "dumps" energy back into the alternator whilst fully energizing it while the original equipment energizes the alternator only the energy it "believes" it needs.  (It's belief is based on how you set the regulator up... screw inside that "tells" or calibrates the regulator so it knows what to do).  The Ford regulator is discussed in detail in PinHead's thread.  The downside to that solution is that you run your alternator "flat out" all the time thereby warming your alternator more than necessary.  Is that all bad?  Generally, they seem to work okay as do some aftermarket solutions (some folks here report good results) but you are unnecessarily heating (and therefor using up life of) your alternator windings.  Again, the Honda guys had an elegant and robust solution to the regulator (but a weaker solution for the rectifier).   

The rectifier "rectifies" the AC into DC.  This is more straightforward.  It requires 6 diodes (three phases both ways).  The diode selection is key to the rectifier's "robustness" and efficiency.  The Honda part was not particularly forgiving if you hook up jumper cables backward (for example) and once blow or partially blown, your charging system is doomed to produce bad results. 

The thing that's not covered well here on the forum is that the regulator from Honda is well engineered and difficult to beat because it does not beat up your alternator as many of the aftermarket solutions. 

For the sake of clarity, your rectifier turns AC into DC.  You need this because your alternator makes AC and your charging system/electrical system needs DC to survive.  Your regulator controls the output of your alternator to charge your battery (and support the electrical system) the correct amount. 

[TwoTired]

Like this nx250 rectifier

No, but I give up.  You'll do whatever you want, me thinks.

[dave500]

if the nx250 has a permanant magnet alternator its reg wont work on your old honda.

[crazypj]

It depends which Honda you want to use it on.
CB350/400F, 500/550F, CB750Four, no chance as they all have EMF alternators
  Kawasaki 636 is PMS (like all modern sport bikes I've ever worked on.)
 Last one to use EMF system was Suzuki GSX-R 1100, (around 1993~4?)
Suzuki continued using same system until 2007 on Bandit 1200/600 SACS motors

Ok so let me get this straight
bike needs juice- Regulator sends signal to alt... Powers up magnets(like in most car alt) then alt makes three phase power(ac) then rectifier lobs the bottom off leaves you with dc....... So could I use the reg out of a 12v car alt and any straight rectifier?

Not even close? ? ? ? ? ? ?

Dave500 has about the best solution below

[dave500]

i use these little bosch regulators,,they are the electronic replacement for the external tin box electro points unit used on 35 amp auto alternators,im also using a rec/reg from a permanant alt bike but only for the rectifier part of it.


  youll see ive snipped a couple of the wires of the rec/reg unit,ive only connected the rectifier part.

[crazypj]

Dave, is there an actual part number of or just Bosch RE57? (all the letters are just too close together )

[dave500]

9190067010,ive run these for a few years now,they cost about $30 here,they are on a few euro cars aswell.

[dave500]

the electro magnetic field strength is varied for the regulating effect by altering the voltage the field coil receives.

[dave500]

no they dont,it dosent seem to sink in sometimes,its a lot better than "dropping the bottom of your wave"?

[Mtmooradian]

I'm going to use stock reg. and the nx250 rectifier.
And if you look at a wave form "dropping the bottom off" is good Half-wave rectification description.

[crazypj]

I'm going to use stock reg. and the nx250 rectifier.
And if you look at a wave form "dropping the bottom off" is good Half-wave rectification description.

 Yes it is, but it's not what happens on any of the SOHC 4's

[Mtmooradian]

I didnt know that it used a full-wave rectifier, not a big fan of people being snotty....

[Rgconner]

Then grow a tougher hide.

From the look of it, the "snotty" people saved you wrecking your charging system.

[Mtmooradian]

Yeah not really..... I'm doing my research, asking questions on a furum shouldn't be met with snotty comments. We are supposed to be working together to help each other. And it's funny that the set up I've proposed(and been critised for) is the same system dave500 runs.... His comment about my rectifier issue had nothing to do with rectifiers.....

the electro magnetic field strength is varied for the regulating effect by altering the voltage the field coil receives.

That's pertained to the regulator.... Which I'll be running the stock reg.... A full wave rectifier (with no reg)from a  nx250 should be fine....

[Bodi]

Looking at the picture of the NX250, I see three yellow wires and two other wires. That certainly looks like a 3-phase rectifier, and it should work fine.

[scottly]

You can use a Ford pickup truck regulator (part number is in PinHead's thread) but it acts as a "shunt" regulator instead of controlling how much you "excite" your alternator like the regulator from Honda (those guys were smart).

This is not correct. The Ford regulator controls the field coil. It is not a shunt regulator.