PMA Powerdynamo and Pamco no good combination?

[XSFrits]

Hello,

This is my first thread. Hope you guys could help me out.

I have bought a new dynamo and regulator at a dutch XS650 webshop. I have problems with getting enough power out of the regulator/dynamo.
I do have spark (dual coils) when I kick it with the battery attached. So Pamco on battery is not the problem. I also have a capacitor/condensator 25v/15000. Is this the problem? but that does not explain the low voltage out of the regulator...or does it?

The people at Powerdynamo asked me to send it to my reseller if I think the material is not working correctly. They cannot help me, because third party (pamco) is involved.

I want to know if you people think the powerdynamo or regulator is not working correctly.

Please help, I am so stuck right now and want to finish off the bike.

Here are a few things i can already tell you:

- I have 0.7 ohm on black stator wires when installed, and also 0.7 ohm when not installed.
- no pinched wires
- no bad smell on regulator
- ac voltage is 5 on black wires when kicking
- dc output regulator 0.2-1.0 volt when kicking
- no burning light when 12v bulb installed directly on regulator
- i see no weird cracks on the coil wires.
- Pamco should work starting with 5volt dc

Do check the photo with the non attached white and red wires coming from the big coil
Does this mean anything? Keep in mind a have a separate timing (pamcopete) on crackshaft. So is this just an optional part for giving voltage to a possible pickup?

 

[XSFrits]

i made the wiring like below

 

[Signal]

Just to confirm.
1. Spark when you kick the bike over and use a battery?
2. No spark when you kick the bike over using the capacitor instead of the battery?

If the above is true then the alternators output may not be enough to run the bike without a battery.
Do the makers /suppliers of the alternator state that it will run a bike using a capacitor only?
From your diagram you have a single phase alternator and I suspect this is why it will not spark when you use the capacitor only. The ripple on the output from the single phase rectifier is possibly too much for the capacitor to compensate for.

You could either run a battery (even a small one) or try increasing the size of the capacitor (run others in parallel). Lastly you could get an alternator that will run the bike using a capacitor only.

The voltage readings are low because the rotor/ crankshaft are not turning at a high enough speed when you kick the bike over. As the rotor/crankshaft RPM increases the voltage increases until the regulator has to start diverting the excess energy to ground.

 

[XSFrits]

Thanks for your reply Signal.
1. Yes
2. Yes

The supplier state that the bike will run with capacitor 20000uf. So right now i only have 25v 15000uf and that is not enough/right. It doesn't say it works with a pamco (which needs minimum of 5 volt). Source: website powerdynamo.

If i increase the size of the capacitor or parallel them, will i get to 5 volt to get spark from Pamco? If i kick the bike a few times, will it fill up the capacitor? Or will it get drained? If so, i may never use capacitor only...

Can you tell me what kind of capacitor i should use? Better save than sorry. 12v or 25v and how much uf.

How come other alternators produce more volt when kicking? Its like that right?
So is the pma from hughs better then powerdynamo if it concerns working with pamco?

 

[pamcopete]

XSFrits,

Make sure that your headlight is off when kicking to start. In fact, make sure all lights are off when starting.

Is the regulator a combination regulator / rectifier? You need a rectifier as well as the regulator.

 

[Signal]

XS Fritz,
Why not just use a battery? However if you are set on not using one;

What dynamo system do you have?
From the website system 71 69 999 00 needs a battery to start, if you have that model then that’s your answer.
From the diagrams it also looks like they supply a regulator/ rectifier.

Assuming that you have one that will start without a battery increase the size of the capacitor to at least what the manufacturer specifies. The one you are trying to use is smaller than they specify.

I have no experience with Pamco ignitions or your alternator and cannot say if increasing the size of the capacitor to that specified by the manufacturer will enable the bike to start or not. But I would try it.

Pamcopete is the manufacturer of your ignition.

Capacitors charge to the peak voltage so it would need to be more than 12V. On this site there are several threads about using capacitors with alternators, you will find your answer there about what size and type to use.

So far as the alternators a single phase alternator has one winding in the stator. Its output is a sine wave. After full wave rectification its output will look like two halves of the sine wave next to each other per revolution of the alternator.

A three phase alternator has three windings off set 120 degrees from each other in the stator. The output is 3 sine waves 120 degrees displaced. After full wave rectification the output looks like six half waves crammed into the same time interval. I have drawn a picture that might help.
The result is that you get less variation in the ripple of the output from 3 phase rectifier. You get more bumps but the height of them is smaller so the capacitor is more able to compensate.

The effect of the ripple in the single phase alternator will be more noticeable at low RPM. For your application I think a three phase alternator is a better choice than a single phase one.

 

[XSFrits]

XSFrits,

Make sure that your headlight is off when kicking to start. In fact, make sure all lights are off when starting.

Is the regulator a combination regulator / rectifier? You need a rectifier as well as the regulator.

Hello Pete,

All lights are off. Its a rectifier and regulator in one.

 

[pekka]

Try to kick a few times with the ignition off to charge the capacitor and the turn the ignition on and kick again. Might work if your capacitor is wired so that it is connected to the reg/rect when the ignition switch is off.

Too bad they have cut the CDI coil wires off. An XS650 with a DIY CDI ignition would be nice...

Pekka

 

[XSFrits]

XS Fritz,
Why not just...QUOTE]


I just wanted to symplify the bike.

What can I do?
- use a very small 12v battery with low amp? Just to get enough voltage to the Pamco (yes i can, 12v 0.8 ah so I can kick twice!)
- use a bigger battery 12v 4ah and place it under the swingarm.
- Buy a 30 euro costing capacitor which may not even get it working. That makes me have to buy an new a 3 phase alternator and sell this powerdynamo.

If I use the single fase alternator with battery, will it be as good as a 3 fase with battery?

other options?

semi off topic question:
Why did the manufacturer made the stator single fase? because it has a pickup which stands in the way? and it cannot get its windings off set 120 degrees from each other? If it didn't have a pickup, he surely would make a 3 fase winding?

 

[XSFrits]

Try to kick a few times with the ignition off to charge the capacitor and the turn the ignition on and kick again. Might work if your capacitor is wired so that it is connected to the reg/rect when the ignition switch is off.

Too bad they have cut the CDI coil wires off. An XS650 with a DIY CDI ignition would be nice...

Pekka

how many times do you think I have to kick (with ignition and lights off) before it has enough to get the Pamco working??
Keep in mind I have dc output regulator 0.2-1.0 volt when kicking. Is it as simple as adding up the voltage.. cannot be, right?

i cannot test it right now, because I took if off the bike..

 

[pekka]

What can I do?
- use a very small 12v battery with low amp? Just to get enough voltage to the Pamco
...
Why did the manufacturer made the stator single fase? because it has a pickup which stands in the way? and it cannot get its windings off set 120 degrees from each other?
And I do not even use the pickup..!

I quess a small battery would be the easiest option.

Single phase stator is cheaper to build. 1 winding is easier to do than 3. The other coil is the high voltage coild to drive a CDI ignition. Pickup is separate and usually outside the rotor (see images on the PowerDynamo site).

Pekka

 

[pekka]

how many times do you think I have to kick (with ignition and lights off) before it has enough to get the Pamco working??
Keep in mind I have dc output regulator 0.2-1.0 volt when kicking. Is it as simple as adding up the voltage.. cannot be, right?

Do not know how many it will take. The voltage should just keep adding if nothing is draining the cap. The output voltage of the PMA depends on both the RPM and the load. The cap takes a lot of energy first as it stores the energy but t should hold the voltage with no load. Notice that the ignition will drain the cap allmost instantly when it's charging the coil. Hook up a DMM to the cap and kick with no ignition and see what happens

Pekka

 

[XSLeo]

I went to powerdynamo.biz They list several kits for the XS650.
73 76 999 00 is an alternator and ignition.
73 76 999 HR is different but I'm not sure why.
71 69 499 00 is just the alternator with no ignition.
I assume this is the unit you have. It states right in the product description, "Although technically the alternator functions without a battery, the battery is required for ignition. You can not trust that the produced during start up current for the ignition enough.
That's how google translated it.
It sounds like that with out a battery at the speeds you can kick it over with the kick start may not provide enough current to power the ignition.
You can try adding more capacitors but I doubt it will work.
When the manufacture says to use a battery then use a battery.
The Hugh's kit and others like it work because they have more output. The Power Dynamo is a 180 watt kit Hugh's is a 200 or 220. Hugh's is also a three phase alternator. The three phase puts out more power at all rpms than a single phase. signal tried to explain it in his post. The single phase puts out power just once per revolution, The three phase puts out power three times per revolution.
If each power pulse was say ten volts the single phase is putting out ten volts per revolution. The three phase is putting out 30 volts per revolution.
When kick starting you may get just one or two revolutions of the engine. A ten volt pulse may not get the ignition to fire but a 30 volt will.
Now once the bikes up and running the rpms increase at idle the voltage pulses may be 20 volts After rectifying and regulation you get 13 volts at idle.
The three phase with three 20 volt pulses after rectifying and regulation you still get the 13 volts or so at idle. Once the rpms are this much or higher the single phase and three phase both have enough out put to run the bike.
About the only single phase alternators out there any more are lawn mowers and other small engines. Some small bikes and atv's use a single phase. Like up to 250 cc's. This engines have the ignitions built in and are often CDI. these don't take much voltage to run. They charge a large capacitor then when triggered they discharge through a coil to fire the plugs.
One way to test a capacitor is to charge it by touching the terminals to a battery. After a few seconds of charging you bridge the terminals and even before the circuit closes a spark will jump the gap. Caps charge slowly but discharge instantly. This is part of the spark you see.
Leo

 

[pekka]

The Hugh's kit and others like it work because they have more output. The Power Dynamo is a 180 watt kit Hugh's is a 200 or 220.
...
If each power pulse was say ten volts the single phase is putting out ten volts per revolution. The three phase is putting out 30 volts per revolution.
When kick starting you may get just one or two revolutions of the engine. A ten volt pulse may not get the ignition to fire but a 30 volt will.
...

They work because they are 3-phase and thus produce allmost proper DC-without any cap or a battery. A watt is a watt no matter if it comes from three phases or just one.

You will not get 30 volts from the stator because the phases are angled 120degrees. After rectification you'll get pulsing DC (like in the picture in the earlier post) that can run a Pamco (or points even) because the voltage never goes to zero (unlike in the 1-phase system).

Pekka

 

[XSLeo]

At kick start kicking speeds of 2 or 4 rpms the output between the three phase and single phase can be very different. A three phase gives out three pluses per revolution where the single puts out just one. Sounds like a big difference to me.
On any alternator the rpms of the rotor have a very strong effect on output.
The single phase puts out 180 watts at 5000 rpms. At idle the out put can't be 180 watts the rpms are not high enough. I can't say just what the idle output of the single phase is but it's not 180 watts. From the post on the differences between the single and three phase, the three phase is putting out more three times the power per revolution.
This combined with the difference in power output. 180 watts vs 200 or 220 watts. This increase will be percentage wise as much at kicking speeds as at 5000 rpms. Lets just average the 200-220 and call it 210, that's 16% more watts than the 180. 16% is quite a bit. What would your bike run like with 16% more power.
Not only 16% more but in three times the pulses. This leads to a higher, steadier power at kicking speeds.
So better starting.
One way to look at it is the single phase might put out 4.5 volts at kicking speed. The coil is what draws the current, not the Pamco. The coil needs 5 volts. No fire. The 3 phase puts out 16% more. 4.5 x 16% = 5.2 volts. Ah ha it fires.
Leo

 

[pamcopete]

I copied this wiring diagram from the PowerDynamo site. It shows a ground coming from the stator. I don't know if this is just a symbolic representation for the frame ground or if you are supposed to have a separate ground from the common side of the windings.

 

[pekka]

Leo

Not trying to start a fight here. Actually we agree on this but from a different point of view.

"One pulse per revolution" (or one cycle of sine wave) is only true for two pole alternator. The one here seems to have several poles.

A single phase alternator can be made to generate just as much power as a three phase (but it is propably not economical and does not have as good efficiency. Maybe. I'm not an expert...). With three phase you just combine the power from all the phases and with single phase all power comes from one phase. It is just a matter of designing the stator properly.

But things change dramatically when you rectify the output: 3-phase gives "actual" DC and 1-phase gives pulsing DC (where the current drops to zero). Naturally the coil is the part that consumes the power not Pamco or points. A spark is generated when the current flowing through the coil is suddenly interrupted (drops to zero) and the flyback of the coil creates the high voltage to the secondary of the coil. What happens if the rectified pulsing DC goes to zero while the coil is driven? I dont know. Propably not a spark but energy will propably be draned...

I don't think that a setup with 1-phase PMA, a TCI ignition and no battery is a good idea. But the reason is not the voltage output, it is the lack of continous DC. Seems that this 1-phase does not have enough output to charge the cap enough to keep the current flowing.

Pekka

 

[XSLeo]

Yes. I think we are looking at it differently but came to the same conclusion. This set up needs a battery. Just like the manufactured said.
Leo