Rectifier/Regulator replacement list

[rustybronco]

thank you Rustybronco. I was just worried that I wouldn't be able to wire it up. I dont mind doing a little "clearancing". I hope it helps my bike keep up with the driving lights I added when I bought it. I'm blind as a bat at night lol.

your welcome. my FH010BA is under my counter with the 5 wires attached to it, ready to be installed this weekend.

clearance (I know what you meant) is not the issue, mounting hole spacing is. do not modify the holes in the R/R, modify the bracket where it bolts up. if I can help with anything more, just ask.

my point in all these discussions, has been just for situations like yours.

***EDIT*** What kind of bike?

[rustybronco]

I probably won't be able to get to the other part till mon if you still want me to.

At this point no, it won't be necessary to expand on the 2nd point and I understand what you are saying.

now I have to figure out if there is any advantage to rewinding the stator with a heavier gauge wire (if possible) and seeing if there is a increase in efficiency by bringing down the stator output voltage closer to the regulated voltage and any "possible" increase in current available for those that need the extra for lights, vests ect.

yes I know that a rewind will result in different voltage and current curves per a given rpm. what I am looking to find is, what is the practical limit to power available and is there any advantage to rewinding, other than durability.

Thank you for your input.

thank you Rustybronco. I was just worried that I wouldn't be able to wire it up. I dont mind doing a little "clearancing". I hope it helps my bike keep up with the driving lights I added when I bought it. I'm blind as a bat at night lol.

Another way to look at it is that some of the reduced voltage loss simply gets "eaten up in the stator" instead of the diodes/fets.

I suspect that the OEMs are using the fet regulators mainly because they move a lot of the heat generated during shunting "away from the R/R to the stator", which is better able to handle it.

Martin

with voltages regulated to the same value,
plus considering the stator has a fixed resistance and the impedance of the stator should be the same with the "differences in resistance" between the scr and fet r/r's.
would you please explain why?, so I may absorb your answer. (my educational value only)

***added thoughts*** the only factor that would change the power dissipated in the stator would be, if the capacitance of the changed device (R/R) was different from the OEM values, and that would be true with the Honda and FET R/R.

the series load formed by the fixed loads (lights, devices) and the battery in parallel, would decrease as the battery charged up because of it's increased internal resistance nearing a full charge. therefore limiting the current in the circuit.

if the above is correct, that would make the FET style R/R the better choice in R/R's.

I only have a bit of time during lunch, so I'm not sure I can address all of it today.

First, just to be clear, my two paras you quoted were meant to apply to different aspects of the R/R operation.
The first was primarily to explain why the FET may have less advantage at Low RPM than it would seem to (although I guess it applies during shunting too)
The second was to explain why I suspect the OEMs use the FET type (apparently especially for high current ones)

Ok, let me try to explain my second para better first.
I know how the SCR type work, but prior to this thread have not seen any info on the FET type.
I assume Posplayr's description of operation in post 10 to be correct. If not, then none of this holds ...
(As an aside ... it would be possible to run an FET type in a manner where it doesn't shunt, but instead disconnects the stator leads for a portion of the cycle.
This would reduce currents (and heat) by a LOT. But it would have its own issues (the stator leads would go up to 120 volts at times for instance))

But anyway ...

The R/R has to get rid of any heat it generates.
This heat is equal to V*I losses in the R/R.

During those parts of a cycle where the R/R is rectifying (but not shunting) V will be the "diode" losses.
Where an actual diode is acting as the diode (top and bottom in a standard R/R or the top diode in a FET R/R) this V will be .7 to 1.4 Volts.
Where a FET is acting as the "diode" (the bottom of a FET R/R) this V will be .3 volts or less.
The currents will be similar, perhaps a bit higher for FET type.
(if the current is higher, the R/R will compensate by shunting a bit higher % of the cycle)
So the total loss of a standard R/R is 1.4 to 2.8 volts
The total loss of a FET type is 1.0 to 1.7 volts
So the heat will be significantly less for a FET R/R for this portion of the cycle.

During those parts of a cycle where the R/R is shunting, V loss will be:
For a standard R/R one diode drop (0.7-1.4 volts) plus 1 SCR drop (0.7-1.4 volts) total 1.4 to 2.8 volts
For a FET R/R during shunting it would be 2 FET drops (approx 0.3 volts each) total .6 volts or less
Depending on the stator's V-I charachteristics, current will be slightly to a good bit more.
So the heat generated during shunting is 1/4 to 1/2 as much as a non-FET.

Because the current will likely go up a bit for a FET type, the losses (and heat) in the stator will probably increase a bit.
So the R/R runs a LOT cooler, but the stator a bit higher ... but the stator has an oil bath to help carry away the heat ...

I probably won't be able to get to the other part till mon if you still want me to.

[rustybronco]

Another way to look at it is that some of the reduced voltage loss simply gets "eaten up in the stator" instead of the diodes/fets.

I suspect that the OEMs are using the fet regulators mainly because they move a lot of the heat generated during shunting "away from the R/R to the stator", which is better able to handle it.

Martin

with voltages regulated to the same value, plus considering the stator has a fixed resistance and the impedance of the stator should be the same with the "differences in resistance" between the scr and fet r/r's.
would you please explain why?, so I may absorb your answer. (my educational value only)

***added thoughts*** the only factor that would change the power dissipated in the stator would be, if the capacitance of the changed device (R/R) was different from the OEM values, and that would be true with the Honda and FET R/R.

the series load formed by the fixed loads (lights, devices) and the battery in parallel, would decrease as the battery charged up because of it's increased internal resistance nearing a full charge. therefore limiting the current in the circuit.

if the above is correct, that would make the FET style R/R the better choice in R/R's.

<snip a bunch of stuff I agree with>

The benefit of the FET regulator is that it can achieve this full output at lower RPM than the SCR R/R due to lower losses in the FET R/R.

Pos

I don't disagree with this, but wonder how much of a benefit it really ends up being.

At any given RPM, the stator output will have some curve of voltage vs current. (i.e. how "stiff" a voltage source the stator is) The slope of this curve will determine how much extra current you get for the ~1 volt less loss.

My impression is that the stator is not a stiff voltage source at all, meaning that you don't get a whole lot of extra current. (admittedly a guess, but I believe an educated guess)


Another way to look at it is that some of the reduced voltage loss simply gets eaten up in the stator instead of the diodes/fets.

To get an accurate idea of how much better you do with the FETs would require either some pretty accurate testing, or some much more involved mathematical analysis than has been done so far in the thread.
(Specifically you would need to provide a better analysis of the stator as a voltage source, as well as probably considering the compliance of the battery (and probably the loads too ... incandescents have pretty funky voltage/current charachteristics too I believe))

I'm not saying you don't get SOME gain from the fets, but I think in real terms it ends up pretty negligible, and you could do better by turning your idle up by maybe 25 rpm.
And once you get to an rpm where the regulator is starting to shunt, (which is all rpms during actual riding) there's no advantage.

I suspect that the OEMs are using the fet regulators mainly because they move a lot of the heat generated during shunting away from the R/R to the stator, which is better able to handle it.

Martin

[rustybronco]

So...if i'm reading the list right...a r/r from an 05 kawasaki zx10 would work fine...right?

http://cgi.ebay.com/ebaymotors/ws/eB...m=250384316690 that's what I bought

***note*** the bolt hole spacing is wider than the stock R/R by about 3mm (.110).
I would suggest at this time, mounting it with one bolt and modifing your mounting bracket or finding an alternate means of tying down the other mounting hole (zip tie, metal strap, modified bracket?) ***at this time I believe the bolt hole in the FH010BA should not be modified***

if you would like, you can widen the 2nd hole in the mounting bracket, (on the bike) and put a nut, bolt and lock washer through the 2nd hole.

So...if i'm reading the list right...a r/r from an 05 kawasaki zx10 would work fine...right?

You have it! In actual fact the majority of R/R's will work as long as the current rating is not lower and it is three phase and not for a field regulated alternator.
If you have one of the FH models consider yourself very fortunate.

So...if i'm reading the list right...a r/r from an 05 kawasaki zx10 would work fine...right?

Very Nice write up.

And LOL I thought I had overlooked something

U can always update it Andre. .

Pos

Jim, basically I was first supposed to sit down and trim it down, remove repeats etc, but I have just been too lazy as it was written over a long period. I call it the "longwinded" one. Maybe I will just leave it as it is until I have nothing better to do!
Keep well.

[posplayr]

Ed

EDIT: I'm retracting the statements below that are in quates

I was going to explain this in detail, but then realized that the R/R and the load are in series with the stator. So the total power delivered by the stator is pretty much the same independent on how it is distributed between R/R and load.

The prior discussion/assumption was that since the FET R/R did not drop as much voltage, it was putting a bigger load across the stator. I don't think this is true. I'll check but I think it simply means there is more power available (at lower RPM) than what would be available from the lower efficiency SCR R/R.

A counter example, lets say both an SCR R/R and a FET R/R are operating at 5K RPM. Both are delivering the required load current at the same specified output voltage. Then the power drop is the same in either R/R as the stator is doing the same thing and the load is current is the same.

The FET regulator has to dissipate the same power as the SCR regulator.

This is still true. See a later post on overall operation.

The benefit of the FET regulator is that it can achieve this full output at lower RPM than the SCR R/R due to lower losses in the FET R/R.

Pos

[Nessism]

the time tested Honda would be the choice for those with stock charging system needs, or with an unknown stator condition.

at this time I believe the FH-series R/R (FET) should be used with a known good stator with no flaking/bad coating, or a properly rewound/new stator. I plan on testing a FH010BA with a 27 year old stock stator on my '82 gs to see if I can stress the stator (make it fry). then combine it with a rewound stator sometime in the future on my '80 gs.

the FH-series, in my opinion, would make a nice choice for those seeking the maximum power out of the stock charging system when used with a proper stator, "for those that need it".

***edited*** I can't speak for ALL the cbr1000rr reg's, yet...

Why would the type of R/R add stress on the charging system? Seems to me it would add less.

[Nessism]

OK...so now that my eyes are spinning in opposite directions and I feel like a 3 year old in a genetics class.....what would be the best choice for my '82 850glz? LOL I ask this because when I put my bike away last year I noticed it wasn't charging as well as it should.

The Honda CBR type R/R will bolt in place under the battery box just like a stock R/R. That's what I'm using - I have the shunt type and works great.

[posplayr]

Matchless

Very Nice write up.

Oops...! Was not ready for publication yet, but too late now

And LOL I thought I had overlooked something

U can always update it Andre. .

Pos

FYI

Bikecliff has a nice writeup recently updated on Rewinding Stators. Discusses the relative merits of a stator rewind re: space, increased volts, heat, current.

Thanks to: Andre le Roux Updated 2009/02/15
and Bike Cliff

Pos

Oops...! Was not ready for publication yet, but too late now