Biting the bullet on charging system

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guest76

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@maylar the FH020AA is the same as the Podtronics and other short-type regulator/rectifiers, so offers no benefit.

The SH775 and the newer replacement SH847 are the series-type that offer the benefit of opening the AC circuit.
 
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guest76

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We are all under the impression that bigger is better - we've been conditioned to think that way.

To that end, many have fitted higher output alternators to our bikes thinking that it's going to be a big improvement and all of our problems are going to go away.
Actually it just introduces a new set of challenges.

The original charging system on a bike was provisioned to charge around the same amount as the electrical loads on a bike draws - kind of a balanced system.

If you look at the electrical consumers (loads) on the MK3 we can do a simple sum to get the worst case scenario:
Biting the bullet on charging system
We draw under 30 amps from our bike with everything electrical switched on.

But typically in normal riding, we are drawing under 10 amps.

The MK3 was supplied with an RM23 alternator putting out 15 amps.

Adding the electric starter into the equation for the MK3 meant that after starting a bike twice in a day, the charging system spent most of it's time recharging a depleted battery.

What this means is that the two zener diodes weren't doing much, weren't getting over stressed or over heating.

The rectifier circuit was converting just enough AC to DC to charge up the battery, and the modest capacitor was helping to smooth out the peaks and troughs.




Adding a higher output alternator means that we are now over producing current, and the unused power being produced but not needed has to go somewhere.

So in a traditional charging system, more current is being dumped through the zener(s) to the frame.
The z-plates will be running hotter (noticeably by touch), but certainly still well within their capabilities.

We are running electronic ignitions with newer coils that as a package (deleting condensers and ballast resistor) are drawing less.
Some people are running LEDs which draw significantly less power.

Yet typically these upgrades are coupled to an uprated charging system that produces more power.




With the introduction of the combined regulator/rectifier everything was put into one unit.

It is the same rectifier package inside the casing - one of these:
Biting the bullet on charging system
And for a three phase alternator, one of these instead:
Biting the bullet on charging system

This is just a package of four diodes in this configuration:
Biting the bullet on charging system

These cost less than $1 to manufacture.


The rectifier is exactly the same as the original Lucas rectifier:
Biting the bullet on charging system
If you look closely, you can see the diodes between the heatsinking fins.


The zener diode piece of the puzzle (the regulator) leaks it's heat to the aluminium heatsink casing.
And because they can be used on positive or negative earth machines, over current is dumped through the relatively small gauge connection wires.

Because the gauge of these wires is so small, short-type units (Podtronics, Tympanium, Power Box etc) also short the AC side, which means the alternator will deal with most of the heat instead of the regulator/rectifier unit.


The only difference in the series-type units (Shindengen SH775 and SH847) is that they open the AC side, taking the load off the alternator stator coils.
Everything else is the same - the rectifiers are the same, the way it's connected up is the same etc...

The quality of the electricity converted with the original charging system, a Podtronics or a Shindengen is exactly the same.

The way they convert AC to DC is exactly the same.

But the way a short-type unit (Podtronics, Tympanium, Power Box etc) is putting additional load on your alternator stator coils.
An issue which is magnified if you have uprated your alternator, or if you have upgraded your lamps, swapping them for LEDs




The most important takeaway, I think, is that bigger is not always better.
The original charging system is adequate, so unless you are adding something that uses more power, remember that you need to keep things balanced.
 
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MichaelB

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We are all under the impression that bigger is better - we've been conditioned to think that way.

To that end, many have fitted higher output alternators to our bikes thinking that it's going to be a big improvement and all of our problems are going to go away.
Actually it just introduces a new set of challenges.

The original charging system on a bike was provisioned to charge around the same amount as the electrical loads on a bike draws - kind of a balanced system.

If you look at the electrical consumers (loads) on the MK3 we can do a simple sum to get the worst case scenario:
View attachment 12456
We draw under 30 amps from our bike with everything electrical switched on.

But typically in normal riding, we are drawing under 10 amps.

The MK3 was supplied with an RM23 alternator putting out 15 amps.

Adding the electric starter into the equation for the MK3 meant that after starting a bike twice in a day, the charging system spent most of it's time recharging a depleted battery.

What this means is that the two zener diodes weren't doing much, weren't getting over stressed or over heating.

The rectifier circuit was converting just enough AC to DC to charge up the battery, and the modest capacitor was helping to smooth out the peaks and troughs.




Adding a higher output alternator means that we are now over producing current, and the unused power being produced but not needed has to go somewhere.

So in a traditional charging system, more current is being dumped through the zener(s) to the frame.
The z-plates will be running hotter (noticeably by touch), but certainly still well within their capabilities.

We are running electronic ignitions with newer coils that as a package (deleting condensers and ballast resistor) are drawing less.
Some people are running LEDs which draw significantly less power.

Yet typically these upgrades are coupled to an uprated charging system that produces more power.




With the introduction of the combined regulator/rectifier everything was put into one unit.

It is the same rectifier package inside the casing - one of these:
View attachment 12452
And for a three phase alternator, one of these instead:
View attachment 12453

This is just a package of four diodes in this configuration:
View attachment 12454

These cost less than $1 to manufacture.


The rectifier is exactly the same as the original Lucas rectifier:
View attachment 12455
If you look closely, you can see the diodes between the heatsinking fins.


The zener diode piece of the puzzle (the regulator) leaks it's heat to the aluminium heatsink casing.
And because they can be used on positive or negative earth machines, over current is dumped through the relatively small gauge connection wires.

Because the gauge of these wires is so small, short-type units (Podtronics, Tympanium, Power Box etc) also short the AC side, which means the alternator will deal with most of the heat instead of the regulator/rectifier unit.


The only difference in the series-type units (Shindengen SH775 and SH847) is that they open the AC side, taking the load off the alternator stator coils.
Everything else is the same - the rectifiers are the same, the way it's connected up is the same etc...

The quality of the electricity converted with the original charging system, a Podtronics or a Shindengen is exactly the same.

The way they convert AC to DC is exactly the same.

But the way a short-type unit (Podtronics, Tympanium, Power Box etc) is putting additional load on your alternator stator coils.
An issue which is magnified if you have uprated your alternator, or if you have upgraded your lamps, swapping them for LEDs




The most important takeaway, I think, is that bigger is not always better.
The original charging system is adequate, so unless you are adding something that uses more power, remember that you need to keep things balanced.

Excellent....,An explanation I can understand!!!!
 

maylar

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@maylar the FH020AA is the same as the Podtronics and other short-type regulator/rectifiers, so offers no benefit.

The SH775 and the newer replacement SH847 are the series-type that offer the benefit of opening the AC circuit.

Well... that sucks. I Googled SH775 and that's what came up, I thought they were the same thing.
 
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Well... that sucks. I Googled SH775 and that's what came up, I thought they were the same thing.
All the Google searches I have done tell me a genuine FH020AA is MOSFET and this includes the suppliers with good reputation such as Ricks who were one of the first to recommend MOSFET's. It is lower rated but for a Norton alternator its still over rated so well suited.
 

maylar

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All the Google searches I have done tell me a genuine FH020AA is MOSFET and this includes the suppliers with good reputation such as Ricks who were one of the first to recommend MOSFET's. It is lower rated but for a Norton alternator its still over rated so well suited.

My 3 phase alternator is rated at 210 watts - I hope this thing will be OK with that.
 

acadian

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A few years back I opted for a series style RR upgrade for my 2011 Speed Triple. The original shunt style unit was still in good shape but I was attracted to the lowered load, hence lower operating temp, on the stator. I did also convert all the lighting to LED, but waited until the series unit was installed having been advised that doing so with the shunt unit would have put serious strain on the stator.
 
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A few years back I opted for a series style RR upgrade for my 2011 Speed Triple. The original shunt style unit was still in good shape but I was attracted to the lowered load, hence lower operating temp, on the stator. I did also convert all the lighting to LED, but waited until the series unit was installed having been advised that doing so with the shunt unit would have put serious strain on the stator.


Isn’t the current being shunted by the regulator when you have LED lights the same current that would have been going through the incandescent lights?

So the stator isn’t “suffering” any more than before?
 

Ted Lang

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Maylar-- that ebay link looks legitimate, but it clearly points to a Shindengen MOSFET "shunt" design, model FH020AA. As said before, this will work just fine and you will probably have no noticeable ill effects. The technology of that regulator is great. MOSFETs have very fast switch-on times and very low resistance once they are "on". This results in very little heating of the regulator itself and thus, theoretically the most reliable regulator type you can buy. If I dare quote Jack from roadstercycle.com, he says of this model:

" The Shindengen Mosfet regulators have been a life saver for thousands of motorcycle enthusiasts. I was introduced to them a few years ago and liked how they performed so much that I started the Mosfet regulator upgrade industry around them. Although the Mosfet is still a shunting type regulator which means (in layman terms) it takes all the extra juice that is not used by your motorcycle electronics and gets rid of it by grounding it to the frame or negative side of the battery. The great thing about the Mosfet R/R is that it has up to date technology. It uses Mosfet style transistors. The old diode types found on most motorcycles today are 60s technology. The up to date technology lets the regulator perform substantially better and run cooler. I have close to 2000 upgrade kits out there running the Mosfet regulators and had literally no issues with them. I started out with the FH012AA, then the FH015AA and now the latest and greatest FH020AA. All have performed above expectations (actually I'm amazed how bullet proof these have been). As far as I am concerned there is no other choice for a stock motorcycle upgrade conversion. The great thing about this regulator is its ability to work with a 2 wire (single phase) or 3 wire (3 phase) stator just by hooking up either 2 or 3 wires to the gray terminal. The Mosfet technology is the best thing going until someone comes up with an affordable series R/R using Mosfet technology. So if you have been wondering about whether to upgrade to a Mosfet or stay with your stock R/R, stop wondering. Whether you purchase it from me or one of my competitors it's the most reliable and best alternative I know of. If you decide to upgrade and you have an charging issue I'll help you out, it does not matter to me where you bought it." Jack

All that said, note that Jack says these shunt regulators are "best thing going until someone comes up with an affordable series R/R using Mosfet technology" . So, he also sells the series model SH847 (but which uses SCRs rather than MOSFETs). He calls those the "stator saver", noting that the stator runs cooler, and notes that they are best for high speed use. They are larger, probably because the SCRs are a little less efficient and generate more heat (in the regulator) than MOSFET based regulators.

As for me, if I had the shunt type installed and working well, I'd not be in a hurry to change it. However, given the choice, I'll spend a bit more and go for the series type. So, Maylar, you bought a great unit. Enjoy it.

Ted






 

maylar

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Thanks for that, Ted. I'm an EE and made a living for a while designing power supplies and battery chargers, so I'm familiar with the technology.

The advantage of a shunt regulator (and even the zener regulator) is that at low rpm / low input voltage they are essentially "off", which means they don't consume any power, whereas the series type will always have an insertion loss. With modern MOSFET technology the ON resistances are very low, and if they use Schottkey diodes the forward losses can be very small, but it'll still be higher than a shunt regulator. My present regulator seems to have issues (won't go above 13.4 volts) so I'm hoping this one does the trick.
 

texasSlick

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Isn’t the current being shunted by the regulator when you have LED lights the same current that would have been going through the incandescent lights?

So the stator isn’t “suffering” any more than before?

The current being shunted is the EXCESS current.

Excess Current = Alternator Output Current minus Load Current (lights, etc)

With LED lights, the load current is less, thus from the equation above, the excess current is greater.

Let's put some numbers on it. Suppose we have a 180 Watt alternator, the bike is equipped with a 12 V sealed beam headlamp (60 W), 1157 stop/tail lamp (25 W), and 2 instrument lamps of 2.5 W each. For this example the lighting load is 60 + 25 + 2.5 + 2.5 = 90 Watts.

Alternator output is rated Watts at 5000 rpm, and actual output is in linear proportion to actual rpm, Thus, for a 180 W alternator, the actual output is 90 Watts at 2500 rpm. For these conditions, the excess current is zero.

Rev up to 4K rpm, the alternator output rises to 144 W, and the excess current becomes 50W = 140 - 90.

Changing to LED lighting, reduces the lighting load by about 50%. For the numbers above, the excess current at 2500 rpm becomes 45W = 90 - .5x90, and at 4K rpm, the excess current becomes 99W = 144 - .5x90

In actual experience, Lucas alternators were robust enough to withstand sinking of excess current without lights ON, so reducing lighting load by changing to LED's should not cause a problem. I caution ... do not aggravate the situation by installing a higher wattage stator, then changing to LED's as well.

Slick

Edit: Corrected my math error.
 
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worntorn

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The current being shunted is the EXCESS current.

Excess Current = Alternator Output Current minus Load Current (lights, etc)

With LED lights, the load current is less, thus from the equation above, the excess current is greater.

Let's put some numbers on it. Suppose we have a 180 Watt alternator, the bike is equipped with a 12 V sealed beam headlamp (60 W), 1157 stop/tail lamp (25 W), and 2 instrument lamps of 2.5 W each. For this example the lighting load is 60 + 25 + 2.5 + 2.5 = 90 Watts.

Alternator output is rated Watts at 5000 rpm, and actual output is in linear proportion to actual rpm, Thus, for a 180 W alternator, the actual output is 90 Watts at 2500 rpm. For these conditions, the excess current is zero.

Rev up to 4K rpm, the alternator output rises to 144 W, and the excess current becomes 80W = 140 - 60.

Changing to LED lighting, reduces the lighting load by about 50%. For the numbers above, the excess current at 2500 rpm becomes 60W = 90 - .5x60, and at 4K rpm, the excess current becomes 114W = 144 - .5x60

In actual experience, Lucas alternators were robust enough to withstand sinking of excess current without lights ON, so reducing lighting load by changing to LED's should not cause a problem. I caution ... do not aggravate the situation by installing a higher wattage stator, then changing to LED's as well.

Slick


I believe the 1157 is 25 watts in brake mode, 8 watts as tailight.
Also there is the ignition load to add.
My MK 3 seems to keep up to it all nicely and will run a heated vest, as long as I'm rolling along, not stop and go at night.
It has a built in reminder to keep the charging level up- vibration!
At 2500 it's pretty annoying, at 3000 it's smooth as butter and making enough watts to keep everything running and show green on the Sparkbright voltage monitor.
Excess heat through the Podtronics reg-
I don't even worry about it. It barely gets warm even in high speed running, no vest.
As far as the alternator is concerned, it was made to produce full power continuously for a given rev point.
Why do we need to change that ?( sh775)
I don't see any downside to the SH775, but between the Vin and the Commando I've done nearly 100,000 miles now on the Podtronics without an issue.

Re the need to get some modern MOSFET on the old bike-
In modern Tig welder world, welders made with MOSFETs are the bad old cheap unreliable units generally avoided nowadays. I'm not so sure they are that bad, but the very low end units are usually MOSFET and the more expensive units are IGBT.
MOSFETs get blamed for a lot of the issues with the early solid state Tig welders.

IGBT is the modern, more reliable switching found on higher end welders.
Then again maybe MOSFETs are just fine for handling a small current such as produced by an RM21 or 23.



Glen
 
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Seems like the best system for the Norton Commando was the one that came on the Norton Commando! ;)
 

worntorn

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I changed to the Podtronics on the Commando when my charging system quit several years ago while about 500 miles from home.
The Podtronics didn't make any difference as the charging problem was due to corrosion on a bullet connector.
So there was nothing wrong with the stock rectifier and zeners.
They are still on there and could be connected if the Podtronics ever packs it in. I doubt it will, I'll probably pack it in first!
 

worntorn

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Not sure
I expect that at source the cheap kind is 6 pennies and the expensive is 8 pennies .

I do know that in the early days Paul Hamon tried out a variety of Chinese solid state rec/regs with his Altons.
He had many warranty issues and eventually bit the bullet by going with Podtronics units, which he supplies now.
They all look about the same externally and may come from the same place, but apparently Bob Kizer , electronics Engineer and original owner of Podtronics, knew
something about the quality and arrangement of the components potted inside that small metal box.

Glen
 
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guest76

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@worntorn - there is a marked difference between an alternator running at full load and an alternator running shorted out (where the internal coils become the load and get excessively hot)

@MexicoMike - I totally agree with you. Unless something has broken, there’s no need to swap anything out
 

worntorn

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So when the RM 23 is running at 3000 revs and producing 100 watts +-, does it care whether that 100 watts goes into ignition and lighting load plus heated clothing load or ( with lights off and no heated vest) ignition load with excess going out to ground thru the Podtronics?
Isn't the Alternator producing the same 100 watts in either situation ?
All the power is headed for ground either way, in the first instance thru heating and lighting on its way, second is directly thru the Podtronics ( ignoring ignition load, a constant in both scenarios)

Glen
 
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