More charging info

worntorn said:
We will only see a half horsepower gain (rm23, rm24 high output)with the series reg. in open mode, still a nice free gain.
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This assumes that the alternator is producing full current when the regulator is active, and we don't really know that this is the case.
 
worntorn said:
Isnt that how permanent magnet alternators work, unless the AC output lines are opened?

Glen
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No. They always produce voltage, as long as the rotor is spinning, but the current is a function of the load that's connected. What we see here are claims that a shorting type regulator will draw big amps from the alternator when it's under light load, and that theory needs to be confirmed or debunked with actual testing.
 
Seems I still do not fully understand the charging system.
My understanding is that with the stock regulation the alternator produces full power for any given rpm. The power either goes to the electrical load of charging for battery and power for lights + ignition or to ground ( heat) thru the zeners, once the high threshold voltage is reached.
The claim about the shorting regulators isn't that they draw more amps, as all available amps are already being drawn all the time by the stock reg, rather that they short the AC legs which builds heat in the stator.
Is my understanding of the stock system incorrect?


Glen
 
Last edited:
Your understanding is somewhat incorrect. The voltage produced by the alternator is a function of RPM and load current. As long as the voltage is under the regulator's control point, no additional current is shunted to ground. Example, if you ride at 40 MPH with lights on, all of the AC current becomes DC load current. Once the RPM comes up and the AC voltage exceeds the regulator's threshold additional current will be drawn by the regulator to limit the voltage. How much current that is depends on How high the AC voltage is and what the alternator's source impedance is.
 
With the battery in the system and voltage below reg cutout, does it not absorb the additional power if lighting and ignition load is, say 70 watts and alt is running at an rpm to produce 100watts?
I have chatted with Paul Hamon (Alton) about this and this was his description of how the permanent magnet alternator works with battery, load and shunting or shorting regulator.
Full output all the time, but proportional to rpm.

Glen
 
worntorn said:
With the battery in the system and voltage below reg cutout, does it not absorb the additional power if lighting and ignition load is, say 70 watts and alt is running at an rpm to produce 100 watts?
Click to expand...
That's not really possible. If the voltage is below the regulator's control point then the alternator isn't putting out more voltage than is needed to supply the load. If it was, then the regulator would become active and shunt the excess volts (and draw some current).
 
maylar said:
What we see here are claims that a shorting type regulator will draw big amps from the alternator when it's under light load, and that theory needs to be confirmed or debunked with actual testing.
Click to expand...

Thats not my understanding of the claim. My understanding is that with a short type regulator, the stator coils are shorted, thus preventing the system from drawing from the stator. Thus any heat being generated has nowhere to go.

Whereas with the open type regulator, the stator coils are disconnected and left ‘open’. With no circuit made, no electrical power is generated. Thus no heat.
 
Fast Eddie said:
Thats not my understanding of the claim. My understanding is that with a short type regulator, the stator coils are shorted, thus preventing the system from drawing from the stator. Thus any heat being generated has nowhere to go.

Whereas with the open type regulator, the stator coils are disconnected and left ‘open’. With no circuit made, no electrical power is generated. Thus no heat.
Click to expand...
The stator is generating voltage as long as the rotor is turning. Short the stator and you draw current, which generates heat in the windings. Witness the photos on the web about melted stators that were shorted.
 
Ok, my understanding (as a layman) is that ‘draw‘ means it extract, pull, take, consume somentimg. Is that what you mean?

Because, with a short type regulator ‘tripped’ and the coils shorted, what is drawing ?

My understanding is that the current has nowhere to go, thus it remains in the stator, thus the heat you mention?
 
Fast Eddie said:
My understanding is that the current has nowhere to go, thus it remains in the stator, thus the heat you mention?
Click to expand...
Yes - draw, consume.

And yes, any additional current consumed by the regulator to maintain regulated voltage ends up as heat in the alternator. A zener diode regulator does that as well, and some of the heat is dissipated by the zener. A series type regulator should eliminate that.
 
I don’t claim to know much about this whole shunt/short/open circuit stuff. It just seems like the approach that is being taken is slightly backwards. I would think the first thing that should be known is how much power a given bike needs to run at idle. That should include ignition, headlights and what ever else that needs power. Some people might need GPS or heated gear, etc.
To test the system my thoughts are:
The regular charging system should be disconnected. The battery gets replaced with a variable DC power supply capable of say 12-15 volts and 20 amps. Start and run the bike at different RPM’s adjusting the voltage and monitor the Amps. Especially at idle (1,000-1,000 rpm). This should give a baseline for power consumption.
Now the hard part, a “spin-tron“ type device needs be be fabricated to mount a rotor, stator and different Reg/Rec’s. for testing. Spin up the rotor to various rpm’s with a load equal to what the bike needs and watch the Voltage and Amps.

Now you know how much power that is needed and if the charging system is up to it. Take into consideration the charging voltage that a given battery needs to be happy. With this information it should be easy (tongue in cheek) to pick the best components to build a balanced system,

TT was pretty close to doing this, the flaw I see in his system is he was limited to the alternator output. What I mean by this is (I believe) he was seeing 4 amps at 2,000 rpm. His bike might be needing 5 amps, but if 4 amps was all he could get, that’s all he will be able to read. These numbers are just an example. That’s why I think the variable DC power supply is needed.
This could all be the wrong approach, but I just thought I would throw it out there. Because its just another hot and humid day where I am at.
I must have gotten lucky because I pieced my system together one step at a time and it seems to work for me. I can run daytime lights off (something I never do now) or lights on (high beam) and heated jacket and see not difference.
 
Deets55 said:
I don’t claim to know much about this whole shunt/short/open circuit stuff. It just seems like the approach that is being taken is slightly backwards. I would think the first thing that should be known is how much power a given bike needs to run at idle. That should include ignition, headlights and what ever else that needs power. Some people might need GPS or heated gear, etc.
To test the system my thoughts are:
The regular charging system should be disconnected. The battery gets replaced with a variable DC power supply capable of say 12-15 volts and 20 amps. Start and run the bike at different RPM’s adjusting the voltage and monitor the Amps. Especially at idle (1,000-1,000 rpm). This should give a baseline for power consumption.
Now the hard part, a “spin-tron“ type device needs be be fabricated to mount a rotor, stator and different Reg/Rec’s. for testing. Spin up the rotor to various rpm’s with a load equal to what the bike needs and watch the Voltage and Amps.

Now you know how much power that is needed and if the charging system is up to it. Take into consideration the charging voltage that a given battery needs to be happy. With this information it should be easy (tongue in cheek) to pick the best components to build a balanced system,

TT was pretty close to doing this, the flaw I see in his system is he was limited to the alternator output. What I mean by this is (I believe) he was seeing 4 amps at 2,000 rpm. His bike might be needing 5 amps, but if 4 amps was all he could get, that’s all he will be able to read. These numbers are just an example. That’s why I think the variable DC power supply is needed.
This could all be the wrong approach, but I just thought I would throw it out there. Because its just another hot and humid day where I am at.
I must have gotten lucky because I pieced my system together one step at a time and it seems to work for me. I can run daytime lights off (something I never do now) or lights on (high beam) and heated jacket and see not difference.
Click to expand...
Surely, the trouble is that the power needed varies. Small things like having lights on or off, bigger things like having the battery charged or not, and really big things like having heated clothing plugged in or not.

Add it all up / take it all away and the difference between min and max requirement, for some, could be huge.

So the issue is that the alternator needs to be able to meet the maximum power requirement when required. And also safely operate when it is only being asked to provide the minimum.

Most of the discussion over the last pages has been how to handle the latter, ie when a lower amount is needed.

And I’m not sure that many of us are much closer to an answer though !

What we need is a clever person, who can speak to the stupid, to investigate and then explain…
 
Fast Eddie said:
My understanding is that the current has nowhere to go, thus it remains in the stator
Click to expand...
Can you say what you mean a different way? Current that doesn’t go anywhere isn’t current (it might be charge): there has to be a circuit. On my two wire stator, the circuit is through the stator coils, the output wires and whatever is between the output wires, such as reg/rec and electrical components, or an experimental jumper lead.
 
Triton Thrasher said:
Can you say what you mean a different way? Current that doesn’t go anywhere isn’t current (it might be charge): there has to be a circuit. On my two wire stator, the circuit is through the stator coils, the output wires and whatever is between the output wires, such as reg/rec and electrical components, or an experimental jumper lead.
Click to expand...
Probably not TT cos we passed my knowledge limit in these matters several pages ago !

But my understanding of the SH775 ’open‘ type regulator is that it does just that, it opens the circuit.

I only read Grants page twice tho, and it didn’t all sink in, and now it’s not there…
 
So, just to make sure we’re all calling apples apples etc, and to test I’ve absorded some of Tillers page at least, do we all agree with the shunting / shorting / open nomenclature below? And the brief layman’s description of each ones functionality? If not, please explain why not in the simplest language you can muster:

Shunting type regulator, excess current is shunted to somewhere where it is then disposed of as heat. This leads to heat build up in the regulator body / heat sink.

Shorting type regulator, excess current is ‘switched off’ by shorting the stator coils. Being shorted, there is still some generation taking place. This leads to heat build up in the stator.

Open type regulator, (like the SH775), excess current is ’switched off’ at source by ‘opening the circuit’ of the stator coils. With no circuit, there’s no generation and thus no (or little) heat.

I await the red pen…
 
Fast Eddie said:
Surely, the trouble is that the power needed varies. Small things like having lights on or off, bigger things like having the battery charged or not, and really big things like having heated clothing plugged in or not.

Add it all up / take it all away and the difference between min and max requirement, for some, could be huge.

So the issue is that the alternator needs to be able to meet the maximum power requirement when required. And also safely operate when it is only being asked to provide the minimum.

Most of the discussion over the last pages has been how to handle the latter, ie when a lower amount is needed.

And I’m not sure that many of us are much closer to an answer though !

What we need is a clever person, who can speak to the stupid, to investigate and then explain…
Click to expand...
I hear you Nigel. But the original post from Glen dealt with trying to keep his battery at charging voltage at idle. There may not be a system that will suit him with anything other than a lead or AGM battery with decent amp hrs. He has a particular set of requirements and anything off the shelf might not work. I can’t imagine this morphing into anything other than that ; ).
My point is if the owner can identify how much power is required on a regular basis then a system can be tailored to their needs. Glen obviously uses his bike much differently than most. I bet the average Commando user is fair weather, lights on, EI (except for some of them Canadian guys, they are a hard core bunch). Once the power consumption is identified the charging system can be build to avoid excess dumping. Honestly speaking, for the average guy this is much to do about nothing, I have 3 phase, Podtronics, original 2 brush starter and AGM battery. Bike is happy, so I’m happy.
Pete

PS, I think Glen might be clever enough.
 
Wow - went through 2 bowl's of popcorn getting caught up on this one. This one has to be right up there with the most entertaining thread that I have read for a while!!

@Deets55 - we have to be hard core - the riding season is too short to be a fair weather rider. And with the price of insurance, I only have my '72 Norton on the road at the moment, so it goes everywhere, rain or shine.

Carry on...
 

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