Author Topic: 12 volt conversion HELP, regulator issues. (Read 7594 times)

Flying J · « **on:** May 28, 2011, 01:48:37 PM »

Background:
im doing a 12 volt conversion on my CB125. I have put in a stator from a cb350t, it is a 12v stator. I have also added a 12v rectifier off a cb350 and a 12v regulator off an unknown bike. I have also swapped in a regulator of a 750.

The problem:
With the regulator hooked up correctly Im only getting around 13v and when the head light is on it drops to the mid 12s. Also no mater what rpm im at the Volts stay the same. Now If I disconect the white wire from the regulator it behaves how it should. Ill get 14v at idle and the volts will increase to 14+ at 4-5k RPMs.

Can i run the regulator with just 2 wires? I dont think i should.
Any help would be awesome here.
Why when i disconnect the yellow wire does it not charge at all?

Here is basically how my system is wired up.

Flying J · « **Reply #1 on:** May 28, 2011, 02:03:54 PM »

Could it be a bad rectifier that is causing this? I have a new rectifier in the mail.

73hutch · « **Reply #2 on:** May 28, 2011, 02:55:51 PM »

just curious, what's the advantage of converting to 12v? i'm working in a cb100 restore and would consider trying it.

Flying J · « **Reply #3 on:** May 28, 2011, 03:53:05 PM »

So far not much advantage as i cant get it to work right. But if it was working you can run 12v blinkers or led blinkers and taillights. If i ever get it to work right it may be possible to run a more powerful headlight. But so far im not convinced its worth it. Stay tuned.

73hutch · « **Reply #4 on:** May 28, 2011, 04:01:26 PM »

hmmm. i would be interested to know how it turns out. i have all the parts to convert it AND i will be doing the wiring from scratch regardless. i have noticed on my wife's cb100 the battery dies way faster when sitting than my 12volt bikes.

TwoTired · « **Reply #5 on:** May 28, 2011, 04:09:55 PM »

Where did you get the wire diagram?
How do you know what mode your selected regulator works in?

Isn't your alternator a Permanent Magnet type?
Did you know that all the stator wires are outputs?

Edit: circuit description/theory of operation.
The yellow and pink is the low output winding and must always connect to the Rectifier ac inputs.
The H/L switch adds two more windings to the alts output, which allow the alternator to behave in maximum mode (compensating for the added load of the lighting.)

The regulator must be a shunt type dumping extra power (above what the battery can/should take) into an internal load. It can do this either by loading the output of the rectifier or loading the windings that were added to the alternator. Loading the windings would diminish what the alternator could make, so that is the approach I would use.

This stator/alternator/system design cannot employ a regulator designed for an excited field alternator, as the alternator has no excited field. This leaves out the regulator types used in the SOHC4s.

Cheers,

scottly · « **Reply #6 on:** May 28, 2011, 06:31:01 PM »

The correct regulator does not have a white wire; it should have a black, a green, and a yellow wire. Check the pic on reply #3 in this thread:

http://forums.sohc4.net/index.php?topic=89081.0

Edit: Your wiring diagram appears to be functionally correct.

Flying J · « **Reply #7 on:** May 28, 2011, 09:21:44 PM »

@ scottly, the reg in the picture is the same one im running. It has a black yellow and green. When i said white i meant yellow i guess. Ill go fix it.

@ Towtired The regulator i believe is the shunting kind. It is the same kind as a 1970 CB350.
The diagram is from cb200. It is the same setup as a 1970 cb350 but its just of the charging system for simplicity sake. So basically i have converted the charging system of the 125 to a cb350 but the reg is not working right. Can i test it? Is the reg on a cb750 the same kind or do i need to find another regulator to see if this one is faulty?

Thanks for the help guys.

Flying J · « **Reply #8 on:** May 28, 2011, 09:35:15 PM »

Just a few more notes not sure if they will help diagnose or not. At idle the yellow, pink, and white wires from the stator are putting out 7volts each.

I unplugged the regulator and the battery voltage climbed to 14 volts and stayed there. I have another regulator on a 350 sitting out back. Ill pull it off tomorrow and see if it produces the same results as the regulator.

Flying J · « **Reply #9 on:** May 28, 2011, 09:43:40 PM »

another issue i will have to address is the coil. Here is a quote from the 12 volt conversion PDF

Quote

The original 6V system uses an ignition coil that
has 1.8 Ohm resistance. This limits the current
through the ignition to approximately 3.3 Amp.
Doubling the voltage to 12V would double the
current. Now, this might at first seem like a good
idea: a very hot spark would result. But the downside
of it is twofold: the ignition points would
have sharply accelerated wear (probably last only
25% as long as the old system), and the current
drain from the system will be excessive

So i also think i will look for a suitable 12 single coil replacement. Anybody know the resistance of a CB350 coil?

Flying J · « **Reply #10 on:** May 29, 2011, 10:19:12 AM »

ok so for today, I took a regulator of the 350 on my side yard and put it on. It must be crap because it did not regulate the voltage at all. The voltage reacted just as if it were not there. So i put the other regulator back on and it regulates the voltage at about 13.5. Thats to low. So Im thinking maybe ill try one of these bad boys from oregon electrics. It will plug right in to the spot that the rectifier is and it does both jobs, regulator and rectifier.

TwoTired · « **Reply #11 on:** May 29, 2011, 11:20:06 AM »

I edited my reply #12 above, to clarify how the circuit works. This should help you identify what isn't working on the your system.

You must always leave the yellow and pink connected to the rectifier.

If you disconnect the yellow wire to/at the regulator, the alternator should raise the voltage to the battery (with RPM) Manually disconintue if it goes above 15V.

When you turn on the Headlight, adding both more load and more alternator capability, the battery voltage should still rise with RPM.

The regulator should "load balance" the alternator when it *sees" the rectifier voltage going beyond 14.5v certainly, and maybe even down to 13.8v, but no lower (assuming the alternator is capable of providing both system load and battery recharge with some excess generation.

That's what I would expect, anyway. Describe how your circuit behavior deviates from the above description. Or, you could just keep throwing parts at it.

Cheers,

Flying J · « **Reply #12 on:** May 29, 2011, 11:53:25 AM »

OK, the rectifier is plugged in and not being touched. Now when the bike is on and running with NO regulator it is around 14 volts. With RMP this increases up 16+ volts. This is how the system should behave correct?

Now i have 2 regulators, both the same they look like this

With regulator #1 the bike behaves the same as above. I assume the regulator is bad.

With regulator #2 the voltage at idle is 13.07, @4000 rpm its 13.13 and @6000rpm its 13.20
so to me it seems like the regulator is working but its keeping the voltage to low. Sound correct to you?

Thats why i was looking at that expensive regulator. Using all these old parts it makes it hard to diagnose if its somthing i did wrong or if one of the parts is faulty.

TwoTired · « **Reply #13 on:** May 29, 2011, 12:32:33 PM »

I'd use regulator # 2. It won't allow the system to cook the battery.

Recall that a 12V battery fully charged and rested is 12.6V Even 13.2V is charging the battery, just not very fast.

Also you don't look at instantaneous voltage when charging, you look for trends. Was the 13.2 V and rising, or was that actually the max it EVER went? What is the charge state of the battery?

The battery is your rock in the system. If it changes value rapidly, you are either draining it fast or charging it really fast. It doesn't like either. It just wants to be at full charge all the time. You don't WANT it to drain or recharge fast, you want it it to remain rock-like with a stable voltage. If it is draining or charging you need to look at trends, not absolutes. Only the angels deal in absolutes, the real world tempers everything, even if in very tiny amounts.

What size is your battery?

Is the screw on top of the pictured unit an adjustment? Do you know what is inside the regulator box?

My expectation is that the unit varies the resistance between the yellow and green wires with the voltage sensed on the black and green. The lower the voltage the less resistance.

Does either unit get hot/warm?

Cheers,

Flying J · « **Reply #14 on:** May 29, 2011, 01:25:08 PM »

13.2 was the max charge.
Battery is an AGM 12 volt 3Ah brand new and its resting charge is 13.1

the 13.2 was around 6k rpm, held it up there for a little. The voltage climbed up to 13.2 and then stopped.
As far as adjustment i pretty sure its non adjustable. Ill read through the 350 manual again and see what i can find. The unit is sealed and you cant open it like you can on the 750 reg.

The regulators dont get hot or warm.

Would you agree that it sounds like reg 2 is working but the voltage is being regulated a little low? This is with the headlight off. When i turn it on the numbers drop to 12.8 at idle and when its throttled up it maxes out at 12.9.

TwoTired · « **Reply #15 on:** May 29, 2011, 02:27:05 PM »

It does seem a bit low. What are the voltages if you disconnect the yellow wire going to the vreg?

Flying J · « **Reply #16 on:** May 29, 2011, 02:33:05 PM »

with it disconnected its around 14-14.2 at idle and goes up to 16+ at 5000 rpms. I think ill take the regulator back to the junk yard i got it from on Tuesday and swap it out for another one and see if it makes a difference.

TwoTired · « **Reply #17 on:** May 29, 2011, 04:01:46 PM »

The alternator should add more voltage than it's resting charge, at least when revved. I don't know what is normal for an agm after resting, Wet cell is 12.6-12.8V range.

Looks lik you have one Vreg that doesn't do enough and another that does too much.

That screw with sealant on it makes me suspicious that it is an adjustment. If you own a known bad Vreg, I would be tempted to tweak it. Can't make it worse.

Cheers,

Flying J · « **Reply #18 on:** May 29, 2011, 05:08:49 PM »

here is the battery im using
http://www.ecrater.com/p/10356144/xtax4l-bs-xtreme-agm-powersport#

after letting the bike sit for a few hours i went out to mess with the reg. Checked the battery before i turned on the bike and it was at 13.8! turn the key on and the voltage started to drop. started the bike and let it run for 5 mintues with the headlight on and it stabalized at 13.03. So i turned the screw a few turns out till it got a little hard, nothing turn it back in till it was tight again, nothing. So it is either not an adjuster or its broken as well.

Flying J · « **Reply #19 on:** May 29, 2011, 10:45:05 PM »

Came home and i had left my volt meter on and connected to the battery. It is now reading 14.7. How is the battery gaining voltage while the bike is off. Im going to replace the battery in my meter as its low now because i left it on and see if the meter is messed up.

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Author Topic: 12 volt conversion HELP, regulator issues. (Read 7594 times)