Author Topic: 6v to 12v conversion  (Read 6618 times)

Offline Housewiz

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6v to 12v conversion
« on: 15.12. 2012 17:51 »
Who has had great luck converting 6v to 12v and what parts were used?  I saw the post on bulb choices, the conversion parts listed in that post, although I am in the dark about what the protocol is on converting the dynamo.

Just a little curious about what is needed to provide good lighting at night - not like it's going to anytime soon ai will be motoring around on my Frankencycle.

Thanks,

Steve

Offline warmshed

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Re: 6v to 12v conversion
« Reply #1 on: 15.12. 2012 18:54 »
Just get an electronic control box, DVr2 is what I have used and very pleased with.  Easy wiring just use the wires from existing regulator, only 4, so no electrical knowledge needed, just follow the instructions..  Put in the battery and change the bulbs. The horn will work fine with 12 volts, you may even hear it.

You can even use the regulator to work as 6 volts until you get round to getting a new battery. Only one wire difference.

Only decision to make is what earth polarity do you want, I would suggest -ve earth as most things you buy now like it this way round.
You may have to Polarise the dynamo to change the polarity, easy done, without the regulator connected, run a temporary wire from the non-earthed side of the battery (ie +ve if using -ve earth) and touch it on the F tag of the dynamo, it will flash with a spark.  Remove this wire and connect the regulator.  The "flashing" of the dynamo just changes the polarity of the magnetism of the field coil so it now generates the voltage in the required way. 

Any problems just list on here and help will follow.

Good luck.

Offline Triton Thrasher

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Re: 6v to 12v conversion
« Reply #2 on: 15.12. 2012 19:10 »
There is a disadvantage.

The headlight will soon flatten the battery and go very dim, in urban traffic conditions, because the 6V dynamo does not cut in at 12V until higher rpm than when regulated to 6V.  Many riders use a 10W halogen pilot lamp, or other low-current light in town, for that reason.


Offline Housewiz

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Re: 6v to 12v conversion
« Reply #3 on: 15.12. 2012 19:35 »
I have read somewhere the belt-driven dynamo conversion spins the dynamo gear a bit faster - would that help with low speeds in city driving?

Offline trevinoz

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Re: 6v to 12v conversion
« Reply #4 on: 15.12. 2012 19:37 »
Much better to rewind the generator for 12V operation.

Online groily

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Re: 6v to 12v conversion
« Reply #5 on: 15.12. 2012 19:57 »
I've been running with DVR2s at 12v for years on 2 bikes, and since very recently on my A.
All the above is true, but I live in the back of beyond so the town thing isn't an issue for me. However, using in my case an SRM belt drive, the loads balance at 12v at just on an indicated 40mph in top (with an extra tooth on the gearbox sprocket). One bike, not the A, uses a finer-wound armature and field, the other 2 run on standard windings. The fine-wound dynamo obviously cuts in faster, but the heavier '6v' windings are capable of supporting loads up to 80-odd W and I have had no problems. As i say, I live in the boondocks where trickling around isn't necessary. I've tended to go for meaty batteries - meatier than strictly necessary probably - and am very happy with all three bikes in year-round quite heavy use. It's Horses for Courses really. Cheers, Bill
Bill

Offline Housewiz

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Re: 6v to 12v conversion
« Reply #6 on: 15.12. 2012 20:34 »
Sorry for so many of these rookie questions. 

What is a DVR2?

To "rewind" the generator, what is involved in that?  And who does it?  An electric motor shop?

Trying hard to come up to speed on these A10s so I don't have to ask tons of questions - so many bits of info to inhale and parts to sort out.  It's a very good thing I don't have plans on riding until next summer.  It will take me that long to sort out all this stuff.

Thanks,

Steve

Offline metalflake11

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Re: 6v to 12v conversion
« Reply #7 on: 15.12. 2012 20:58 »
A DVR2 is a brand of regulator, they are very good. Which country are you in? If you are in the UK then I could make some suggestions.
England N.W
1960 A10
England

Offline Housewiz

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Re: 6v to 12v conversion
« Reply #8 on: 15.12. 2012 21:03 »
Live in the good old USA - far away from the treasure trove of mechanics, shops, parts and other related A10 resources your lucky guys have in the UK.  Strange it's like that because BSA exported so many bikes here.  Also, I am just getting into the A10 scene.  Two Brit bike shops around but far too few parts, spares, etc.

Thanks,

Steve

Offline metalflake11

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Re: 6v to 12v conversion
« Reply #9 on: 15.12. 2012 21:22 »
Sorry Steve I can't help you other than with advise. If the dynamo is working ok you can wire it 6V or 12V. The regulator S.R.M. sell is very good, as is the DVR2. They also sell a belt drive kit which increases the revolutions of the dynamo by 10%. This too is an improvement on standard in todays traffic chaos, when riding on sidelights is not really a sensible option. It does of course wear your dynamo out 10% quicker!
England N.W
1960 A10
England

Offline Triton Thrasher

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Re: 6v to 12v conversion
« Reply #10 on: 15.12. 2012 22:00 »
Much better to rewind the generator for 12V operation.

Except, it's physically less robust then.

Offline warmshed

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Re: 6v to 12v conversion
« Reply #11 on: 15.12. 2012 22:27 »
The majority of people use a standard 6 volt generator without problem. The DVR2 (Dynamo Regulator mk2?) can be seen here http://www.dynamoregulators.com/dvr2.php

The SRM/DVL tooth belt dynamo conversion increases the relative speed of the dynamo by 10% and 20% respectively,   and therefore enables the dynamo to balance the load at lower engine revolutions.
I would not think the dynamo would wear out 10% (or 20%) quicker, the mag/dyno set up on many bikes has increased dynamo to engine speed (by 20%) and they don't suffer from increased wear.

The more modern electronic regulators do cut in much earlier than the older ones, unless you are doing a lot of sub 30mph riding you should not find it a problem even with the original chain drive.

If you envisage lots of very slow driving the use of a lower wattage bulb or bright pilot as suggested is, as suggested, worth considering. LED rear lights also help to reduce the load the dynamo has to supply.

All the  bikes I know with 12 volt regulator conversions use the standard 6 volt dynamo without problems and benefit with good lighting, don't forget that using 12volts on the thicker 6 volt wiring gives a reduced voltage loss adding to its efficiency too. I certainly would not go back to 6 volts.

Offline metalflake11

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Re: 6v to 12v conversion
« Reply #12 on: 15.12. 2012 22:50 »
Surely, increasing the revolutions of the dynamo by 10 or 20% (whichever it is) for every mile travelled will result in higher wear and tear of the bearings and the brushes by a similar ammount?
England N.W
1960 A10
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Offline warmshed

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Re: 6v to 12v conversion
« Reply #13 on: 15.12. 2012 23:02 »
Surely, increasing the revolutions of the dynamo by 10 or 20% (whichever it is) for every mile travelled will result in higher wear and tear of the bearings and the brushes by a similar ammount?

Just because it turns quicker does not necessarily mean greater wear, as long as the dynamo is turning within the specified rating for the bearings. I am not sure of the speed rating of the bearings but I don't believe that the extra 20% will ve beyond the working speed of the bearings fitted, especially as not many rider run at a constant 6000+rpm

Brush wear is more related to the current its passing, at 12 volts for a similar load it will be half that of 6 volts so even with increased speed the wear should actually be less than standard 6 volt system..

Offline trevinoz

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Re: 6v to 12v conversion
« Reply #14 on: 16.12. 2012 02:28 »
TT,
      I disagree that a 12V wind is less robust.
I use 0.7mm wire for 12V, 0.8mm for 6V, in the armature.
For the field coil I use 0.6mm instead of 0.7mm.
Hardly a great difference.
The generator will deliver 80W easily, which should be enough for any A10, without over heating.
I don't like the practice of running a 6V generator at 12V mainly because the field coil is drawing around 4 Amps when the generator is working hard.
The coil is not designed for this and will tend to over heat not to mention the 2 amps which could be put to better use.
I have seen enough cooked field coils in my time and the generators were only running at 6V.
I have only had one of my 12V armatures fail in service, with thrown solder. This was found to be caused by a faulty regulator.
Luckily the conductors were not burnt at the commutator and a resolder and new regulator fixed the problem.

Trev.