Series D 6 to 12 Volt conversion

[macvette]

Hi,

Does anyone know how to convert the dynamo and regulator on this model to 12 volts? I'm asking about the original equipment, not an Alton substitution.

Thanks Mac

 

[Comet Rider]

Simple Answer

Whip the dynamo off and give it to someone like Paul Goff, Dave Lindsay who will exchange the field winding for an uprated one, and then fit a solid state regulator inside your original reg housing.

Simple and effective

Neil

 

[nkt267]

My understanding is that with a standard 6volt lucas dynamo, all you need to do is uprate the bulbs and battery to 12volt and use a 12volt regulator.
It was explained to me that the wiring in the 6volt dynamo is of heavier guage to take the amperage,whereas the 12volt wiring is smaller as the current being drawn is lower for the same wattage ie:-30watts @6volt=5amps.30watts @ 12volt=2.5amps.I had a dynamo rewired to 12volts and it performs no better than one I converted with a 12volt regulator.(cost £125 6years ago).But the dynamo must be sound to start with.More ideas will follow from others..John

 

[Tom Gaynor]

12 volt conversion

Change the bulbs, buy a 12 volt regulator, and go. I expect the curse of Taff the Horn to descend on me, but 6 volt horns seem to work OK on 12 volts too. Apparently (according to "recognised experts - which excluded me....) there is no practical difference between "a 6 volt wind" and a "12 volt wind". There are people who will be happy "to rewind your dynamo to suit 12 volts" but if you asked them to rewind it "to suit 6 volts" they'd do exactly the same. It may however be worthwhile having it rewound anyway, because dynamos don't last forever.

 

[hooterman]

12v Regulator

Hi there interesting topic this, can anyone tell me what make solid state regulator to use.

 

[Tom Gaynor]

6 volt to 12 volts.

Can "anyone" tell you? Hell, everyone can tell you: for any ten members there are ten (or more) firmly held opinions......
Sean Hawker (CMES) sells one that I've used for several years (on another bike). Many people swear by Podtronics. AOL do one which I've used. Dave Lindsley probably sells one, but it might be one of those already listed above. Actually the standard Lucas electromechanical one is reliable for what it is, and certainly a great deal more reliable than the Miller atrocity. KTB tells how to convert a Miller dynamo - which isn't a badly made unit - to take a Lucas regulator. I have a soft spot for them: I like the fact that the terminals are marked F A D E.

 

[clevtrev]

Can "anyone" tell you? Hell, everyone can tell you: for any ten members there are ten (or more) firmly held opinions......
Sean Hawker (CMES) sells one that I've used for several years (on another bike). Many people swear by Podtronics. AOL do one which I've used. Dave Lindsley probably sells one, but it might be one of those already listed above. Actually the standard Lucas electromechanical one is reliable for what it is, and certainly a great deal more reliable than the Miller atrocity. KTB tells how to convert a Miller dynamo - which isn't a badly made unit - to take a Lucas regulator. I have a soft spot for them: I like the fact that the terminals are marked F A D E.

That`s funny, to me is says DEAF.

 

[Len Matthews]

AO Services in Watton , Norfolk supply a neat little solid state regulator which can be housed in the original Miller base and cover. They are available in universal form for either 6 or 12 v. systems but you need to state which polarity you require. If using a Miller dynamo it needs to be set up as if it were to be connected to a Lucas regulator-as per KTB. AO Services have a website-your browser should find it for you.

 

[vapide]

The unit AO sells, if its the V-reg listed on their site, will not fit in a Miller case - several of the 6-12 converter manufacturers over the years have made ones that would fit in a Miller box, then stopped, so its probably safe to conclude the Miller box just doesn't offer enough cooling area for a 6-12 converter regulator. Plain old solid state regulators, 6 or 12V, can be made to fit in a Miller box. The VR is a bit odd too because while it is not technically a 6-12 converter, the maker says it can be used in its 12V mode on a 6V dynamo with no modification to the dynamo.

Podtronics has a good screed on their site explaining the differences between the different methods of getting 12V out of a Miller or Lucas.

After playing with several conversions myself over the years, I am about to revert to 6 volts! I'd rather have a system that develops power at the lowest revs possible than one than promises much higher output, but at revs my machine rarely sees!

AO Services in Watton , Norfolk supply a neat little solid state regulator which can be housed in the original Miller base and cover. They are available in universal form for either 6 or 12 v. systems but you need to state which polarity you require.

 

[john998]

12 volt conversion.

Hello, My outfit has a Chinamo, and Gardener 12v set up, it has work well for at least 10 years. This unit will not fit in the miller box, but is easy to hide under the battery platform. Low RPM output is not a problem, perhaps because being an outfit it is lower geared, so the motor is turning faster for a given road speed.
The solo has a miller dynamo with a 6V electronic regulator supplied by the late lamented Ken Bell. This unit fits in the miller box, and has given sterling service for around 20 years. Once again low RPM output is not a problem. He also did a 12v unit, I do not know if anyone still supplies these units, they are built to aircraft standards and work spot on.
My feeling is that unless you do a lot of night riding, or have coil ignition 6V is fine. Use a low wattage halogen head light bulb, and all will be well.
John.

 

[nkt267]

If you bend the fins slightly on the AO services regulator it fits in the Miller box,I've got 2 like that.Or bolt it under the battery support like I did with the Alton one.John

 

[vapide]

I'm a bit puzzled by the AO regulator, because while most of the companies making electronic regulators make a 12 version for true 12V dynamos (which includes 6V ones which have had special 12V coils or coils and armatures installed) and 6-12 converters which let the output rise to 12V while restricting the field to 6V, the AO appears to be just a regular 12V regulator, which they tell you its OK to use on a 6V dynamo without any mods.

The first generation of 6-12 converters had a lot of trouble burning out field coils because most of them cheated, and ran the field coil at, say, 8V instead of 6V (all voltages given are nominal), in order to get reasonable output at lower rpms. But running a 6V coil on 12V does not seem wise.

Oh, one other thing. While its useful to know that the AO will fit in a Miller box with a little fin bending, those fins are there for a reason - to cool the components inside! Which they cannot do as effectively if the are bend and then enclosed so they are out of any airflow. Once again, I'm not sure how important this is, but is is something to be aware of.

 

[Robert Watson]

In the past I tried to run an E3L Lucas 6V on 12V and time and again it failed, eventually spitting out all the solder from between the segments on the commutator. I concluded that although this works in the short term and short usage, whenever it gets used for a lengthy period disaster will occur. With me it was every time I crossed into the closest US State (Washington) which requires daytime use of headlights on a motorcycle and the police pull you over and give you a stern lecture if you don't have it on. Not ever wanting to come under such scrutiny if it can be helped, I find it best to run the headlight, and in early days that meant after about 3-4 hours, a fried generator. My recent Comet aquisition had exactly this same setup, and I was assured it worked well, but had VERY limited use. I checked the generator and it's free running output was something like 12.8 V, perfect if regulated back to 6V but not good to try and regulate at 13.6 V to charge a 12V battery. A 12V generator, like a Chinamo puts out about 25V if left uncontrolled, so when running at 13.6 V works well. I'm no expert at anything - as many will attest - but having let the smoke out of quite a few wires in my time, I prefer using stuff meant for the job. The Comet is now all converted back to 6V!

Robert

 

[Len Matthews]

Two things; the AO services regulator can be used on either 6 or 12v. systems. For 12v. it's simply a matter of severing a loop of green wire that protrudes through the encapsulation-it's left intact for 6v. Ventilation does not appear to be a problem; after all, the unit is designed to be a direct replacment for the inner bits of a Lucas regulator.
Second thing; my understanding is that Chinamos are 6v. units,and like a lot of things from that country, are copies of earlier European designs-in this case Bosch I believe.

 

[timetraveller]

If you require the bike to look standard then you will have to go through all of the above but converting back to 6 volts sounds like too much eccentricity for me. Does one carry spare 6 v bulbs, coils etc when touring because you are most unlikely to find spares whilst on the road. !2 v stuff is everywhere including scrap yards if all else fails. Consider fitting the car alternator conversion suppled by Norman Walker and Dick Sherwin. No original parts have to be chopped about. You get up to 400 watts. It balances a 130 watt headlamp bulb, 6 watt rear bulb, brake light, coil ignitions and heated gloves at about 1,000 rpm on a twin and slightly above that on a Comet. It does not look standard but over 40 units have now been supplied, most to people who use their bikes for long distance touring. None have failed yet. They cost about the same as a Hamon/Alton unit but produce far more power.

 

[Chris.R]

The AO regulator will not fit in the miller box without modifying the box so will have to relocate obviously not an isolated case.

 

[b'knighted]

The Vreg2a that I bought for a Comet did fit inside a Miller cartridge case. I thought that it was made by AO. Faultless easy upgrade that lets a Miller dynamo run 12v coil ignition and LEDs. Doesn’t leave a lot for the upgrading the headlamp.

 

[Robert Watson]

And if you try and pull too much power from the 6V Dynamo the armature will overheat and melt all the solder that holds the commutator segments in and when you pull it apart it will look like a bowl of spaghetti. Go ahead, ask me how I know

 

[MartynG]

For years I ran my Comet with the original 6V miller dynamo with a V-Reg 2 voltage regulator giving 12 V output. Regulator is mounted on the underside of the battery platform. I was aware of the slight risk of overheating the windings in the dynamo so I had LED tail light insert and low wattage headlight globe from Paul Geoff.

I have recently gone all LED with one of the brilliant LED headlight globe units, again from Paul Geoff.

No problems at all but I am running a magneto as well so no ignition load. I would think that trying to run a kettering ignition with any more than say a 35W headlight would be too much for the dynamo and it would self destruct due to overheating.

Martyn

 

[Chris Launders]

The components to convert the dynamo to a proper 12v one are now easily available compared to when this thread started, 12v armatures and field coils are all that are required.