Rectifier/Regulator replacement list

[rustybronco]

For your convenience

body diode

Thanks for the link...
Never heard Diode called that. I must have been away to long.

[Matchless]

Jim,
Keep going here please, although I am not posting I am following this with great interest!
I once looked at the delta configuration and came to the conclusion ( not proven) that a higher current rated regulator needs to be fitted for durability then. I never pursued it any further and would not be surprised if FET shunt regulator fitted bikes now start coming out with delta connected stators.

Then as Rustybronco says, the next weak spot, the stator may not be able to take the strain especially 30 year old ones, maybe new rewound ones using API enamelled copper wire would be OK...?

[reddirtrider]

Thanks for the link...
Never heard Diode called that. I must have been away to long.

They call it that since it's a diode that is internal to a power MOSFET's 'body' (part of the FET, not an external component).

The cathode of the diode is connected to the drain of the FET and the anode of the diode is connected to the source. This configuration prevents current from flowing from drain to source when the FET is off, however, when the FET is on or off, the diode will conduct from anode/source to cathode/drain when the drain voltage exceeds the source.

[rustybronco]

They call it that since it's a diode that is internal to the FET's 'body' (part of the FET, not an external component).

Rodger that... and Thank you!

[duaneage]

Then as Rustybronco says, the next weak spot, the stator may not be able to take the strain especially 30 year old ones, maybe new rewound ones using API enamelled copper wire would be OK...?

Bingo. Although I don't think different wire will make a difference. The limiting factor may be the stator design. Perhaps someone will find a way to graft a newer stator/rotor/magnet arrangement onto our old GS bikes.

[posplayr]

It is late

It is a little late, but I did have a chance to do some more testing today. This time I fabricated a better setup to insure that all connections were tight and secure.

1st I tested the Honda Unit and confirmed that it performed closed loop control based on the sensing wire. It seemed to maintain about 14.3-14.5V over the RPM range once the RPM got above 1250 RPM.

In the range of 1100-1200 depending upon the brights and blinkers creating excess load the charging voltage can vary as there is little excess charge available and it is slow to change the battery voltage. In this lower RPM you can almost change the charging output voltage close to 0.75V for a 100 RPM change between 1100-1200 RPM.

Next I put in the OEM Suzuki unit and it undercharged the most. The way it acted it was not controlling the charge and and I did takes some plots but did not diagnose it much further. It could be broke and it is just the limited charging capacity that limits the battery voltage.

Next I put back in the FH012AA ; I knew that it tended to charge closer to 14 at idle but I wanted to see if I could drop the RPM's raise the load and get it to drop out as well. Sure enough it dropped out as well, but it took more work. Lower RPM and it finally came down to below 13V as well. Not as low as the OEMs but below 13V is below 13V.

So where does this leave us (me)? Seems like the FH012AA is superior newer technology, it tends to produce a better low RPM charge than the others but you can bleed it down as well at low enough RPM. Just guessing the OEM R/R at 1400 RPM is probably like the FH012AA at 1100 (on my bike tonite). So to a certain extent you can compensate by increasing idle.

The upper voltage range of the HONDA unit and the FH012AA were actually quite comparable and perhaps indistinguishable. Both are much better than what I have observed with the OEM R/R which almost produces a proportional voltage output with RPM up to 14.5 to 15.5V.

So speeding ahead 30 years, the $40 Honda unit works petty darn well and only seems to give up a little around 1200 RPM (I've had it for well over a year and never tried it). If you don't trust old electronics and want more capacity and better low RPM regulation, then the FH012AA is an attractive alternative. Mine is now installed on my 83 GS1100ED, but that Honda unit will probably be going onto my 81 GS750EX.

I'll modify the prior posts later to reflect these new measurements.

Pos

[isleoman]

Pos,

This has really been a great thread and its why I respect your analytical approach to research. I also appreciate when you test first and then acknowledge the results and reality even if they don't perfectly line up with your original thesis. I think alot of people don't figure out till late in life that this is how real credibility is achieved as opposed to always being right. P.s I'm not suggesting your research is 100% over.

I am electrically challenged and am so grateful for the expertise on this board from guys like you, Duaneage and others. This thread was a model for how to politely and analytically review a technical issue without letting personalities and egos get involved.

I have truly learned something from you and all involved. Thank you.

PS Duaneage your salvaged Honda R/R is still working like a charm in my bike. You were green before green was cool. If only I knew you guys when I had my 74 Trident I might still have that piece of ..........

[duaneage]

One of the nicest features of these Honda RR is the fact they bolt right in. The hole spacing is the same so you don't have to drill and file to get them to fit. The heatsinks are a little higher but that doesn't seem to affect most installations. To the untrained eye they look original too.

Some bikes have more lightbulbs than others, especially bikes with full fairings and radios, so idle power draw will vary. The condition of the battery makes a huge difference. If the battery is low or weak it demands more from the charging circuit.

I've found in my tests the Honda has a small delay before kicking the charge up. There is probably a triggering circuit in the regulator that waits for the incoming power to be stable at some value before upping the output. I've tried to cut one apart to see what the circuit looks like but could not get through the epoxy. I'd love to see a schematic but SDG does not have one on their site.

[Larry D]

I've been following this thread too. I don't understand it, but following none the less....A few posts back you guys were concerned about the long term health of the stator with the FH012AA.
Are you still concerned about that ?

Luckily my r/r and stator checked out fine with my bike. I would like to get a spare, just in case. Seems you've decided that the Honda units are good and the FH012AA are a little better. The difference being the latter charges better at idle. Do I have this right ? Some of these posts sound like a foreign language to me. Guess I should've learned more electrics in school......

[duaneage]

The FH012AA seems to work well, in fact there are probably a dozen different devices out there that can handle the job, but you have to balance a lot of things in a choice. Regulators are not designed in a vacuum, the engineer knows a lot about what is feeding it and where the power is going. Fuel injected bikes with computers need hefty power supplies today, and the stators are no doubt built stronger to provide the juice.

Since many devices will work it makes some sense to go with the simplest and economical method there is.

The Honda RR has what is arguably a better regulation method than OEM, a larger heat sink to cool the parts, and a more reliable component set that has proven itself. It's action mimics that of the original with greater reliability and better control over bike voltage.
It's cheap insurance to replace the OEM RR to prevent the stator from being damaged. And we know how difficult and expensive a stator can be to replace.

[rustybronco]

So where does this leave us (me)? Seems like the FH012AA is superior newer technology, it tends to produce a better low RPM charge than the others but you can bleed it down as well at low enough RPM...

It leaves us with a R/R that is "robust", has newer components and a efficient design.

The upper voltage range of the HONDA unit and the FH012AA were actually quite comparable and perhaps indistinguishable. Both are much better than what I have observed with the OEM R/R...

But we don't know how much the current output has increased yet.
When I pickup my '82, as soon as the weather breaks, it will be time for me to break out the scope and find out the current output on my Honda R/R install's.

So speeding ahead 30 years

You still have 30+ year old part, that in 20 years will be 50+ years old.
It is nice to see a later built part, that will work.

Thank you so much Pos!

[duaneage]

You still have 30+ year old part, that in 20 years will be 50+ years old.
It is nice to see a later built part, that will work.

In 20 years RR availability will be the least of our worries since at some point key parts will start to become scarce. The ignitors are going to be 50 years old as well as turn signal controllers and other items. Maybe by then we'll be riding 20 year old Hayabusas

[rustybronco]

In 20 years RR availability will be the least of our worries since at some point key parts will start to become scarce. The ignitors are going to be 50 years old as well as turn signal controllers and other items. Maybe by then we'll be riding 20 year old Hayabusas

My friend Mr Matchless already has made up the schematic, for the repair of a 30-50 year old ignitor and he was/is working on a replacement HEI substitution
now if we can get those exhausts, switches, seats, sockets, lamps, frames, motor parts...

I've been following this thread too. I don't understand it, but following none the less....A few posts back you guys were concerned about the long term health of the stator with the FH012AA.
Are you still concerned about that ?

with the stators being 30+ years old, insulation breakdown and the resulting shorting to "earth" is always a concern, regardless of the chosen R/R. most of my concern is not unlike if you were to stand at the edge of a cliff, what would it take, to put you over the edge.
if in doubt rewind it with suitable, thicker gauge wire!

[duaneage]

I'm a little concerned about the future availability of intake boots (and their o rings), rebuild kits, piston rings, and decent tires. Already there are limited choices in tires for the rear, perhaps we should be grateful there are any choices at all. I cut my own gaskets from gasket paper so there is an alternative.

I'm going to get enough parts to rebuild the engine in my GS and seal them up. Particularly items that wear out eventually. If the GS is sold there will always be a market for the parts anyway.

I wonder if fuel injection could be adapted to a GS? Now there is a real idea for a project. Next time I find a part out bike cheap I'm going to look into doing it.

[posplayr]

Modified thread post #49

I updated post #49 with some plots from last nite. I also added a chart of the OEM regulator at idle.

In summary, I had to modify my setup some to get a level playing field for the evaluation. The + R/R's were wired directly across the battery in the second pass (except the SH012AA) avoiding the fuse box and other harness wiring. The stator leads did come though my harness so there are probably some drops there that could be improved by going direct from stator to R/R. I feel the setup is relevant for doing side by side relative comparisons of drop out voltage and regulation at higher RPM.

The drop-out voltage is the minimum voltage across the regulator that's required to maintain the output voltage at the correct level.

The new FET technology in the FH012AA provides lower voltage drop in the lower legs of full wave (diode bridge) rectifier and so the drop out voltage appears to be improved by about 1 volt (give or take) compared to the Honda unit. That means that if the Honda unit output is were at 13.25V then the FH012AA would be at a full 14.25V.

The OEM unit seemed to be another 0.5V lower than the Honda Unit and so it clearly indicates that it has the highest drop out voltage.

I did not get a plot of the OEM unit at higher RPM, but I know that from two other units the regulated voltage keeps increasing to about 14.5 to 15.0 V unless it folds back from too much resistance in the + battery leads.

In Summary:

I think that the suggestion to measure current, while technically correct may be problematic and in fact shed no further light on operation that what can be observed from looking directly at the battery voltage.

You have to recognize that at idle, the charging system doesn't really have a whole lot of excess for charging the battery. Increase the load (e.g. lights) or reduce the RPM
and the battery will start to discharge. It takes a while to see this because the battery is basically a big capacitor and the small amount of discharge current takes a while to show as a decrease in voltage.

Regardless of the above, battery voltage only goes up because more current was pushed into the battery. Battery voltage goes down only because current was pulled from the battery (in the short term). So battery voltage is a proxy for accumulated current and so while it might be "interesting" to measure the current between battery and R/R, I'm not sure it is going to change the voltage drop out levels as that is clearly visible on the voltage charts or by comparing the output voltages under similar conditions.

isleoman: Thanks for your kind comments. While I do jhave a personnel motive (to fix my bike) I also want to contribute back to the board as best I can. I know not every body has a digital scope/laptop they can drag out to the garage to grab charging system plots .

Rusty thanks for pointing out the issue with the earlier readings. I understand better how these R/R's work and what they can and can't do for charging. As explained before, I'm not sure I can go much further. Now I'm going to concentrate on getting the SH012AA properly mounted, heat sunk and connected and then get on to complete a Dyna S/ Coil relay mod. I'll post plans as I think I do it with a minimum of harness chopping or jumper wires.

duaneage: Thanks for providing such a reliable and cost effective solution (Honda Regs). For probably 90% of the GS'ers here the Honda reg is the way to go. Some people are always trying to do better and so now we have the SH012AA .

Pos