Alternator engine with magdyno wiring?

Alternators & dynamos will both work pos or neg earth, however, some of their regulating components are polaity conscious.

An old fassioned regulator box will work for both polarities but the modern solid state items have to match the polarity of the machine. The dynamo will need to be polarised, which is just a case of taking a length of wire from the live side of the battery, ie NOT the side that goes to earth, & flashing it on the field coil terminal on the dynamo (disconect both wires from the dynamo first), you should get a small spark & that's it done,you can then reconect both wires to the dynamo in their original locations.

An alternator will work happily either way round providing it's charge controll components are suitable for the polarity you require. Zener diodes & rectifiers are available for both polarities as are the modern regulator/rectifiers such as Boyer powerbox & the like but must be correct for the polarity you require.

You can pretty much treat the charging system as a seperate part of the wiring but if the machine is wired for dynamo/regulator charging, some of this will most likely need to be modified at the regulator to keep all circuits conected & working. It's realy just a case of removing a couple of wires from the regulator & joing them, probably easier to do than it is to explain but if you are not confident about electrical wiring etc, I would recomend you seek profesional help, there's too much potential for disaster if you get it wrong.

The coil you will need depends on what voltage & system you are using, a 6volt coil for 6volt system or a 12volt one for 12volt systems if you are using points, if you are using electronic ignition, some recomend a 6volt coil even on 12volt systems.

Regards, Tim

Previously tim_gostling wrote:

Alternators & dynamos will both work pos or neg earth, however, some of their regulating components are polaity conscious.

An old fassioned regulator box will work for both polarities but the modern solid state items have to match the polarity of the machine. The dynamo will need to be polarised, which is just a case of taking a length of wire from the live side of the battery, ie NOT the side that goes to earth, & flashing it on the field coil terminal on the dynamo (disconect both wires from the dynamo first), you should get a small spark & that's it done,you can then reconect both wires to the dynamo in their original locations.

An alternator will work happily either way round providing it's charge controll components are suitable for the polarity you require. Zener diodes & rectifiers are available for both polarities as are the modern regulator/rectifiers such as Boyer powerbox & the like but must be correct for the polarity you require.

You can pretty much treat the charging system as a seperate part of the wiring but if the machine is wired for dynamo/regulator charging, some of this will most likely need to be modified at the regulator to keep all circuits conected & working. It's realy just a case of removing a couple of wires from the regulator & joing them, probably easier to do than it is to explain but if you are not confident about electrical wiring etc, I would recomend you seek profesional help, there's too much potential for disaster if you get it wrong.

The coil you will need depends on what voltage & system you are using, a 6volt coil for 6volt system or a 12volt one for 12volt systems if you are using points, if you are using electronic ignition, some recomend a 6volt coil even on 12volt systems.

Regards, Tim

From AL Oz

Just to add a final word to Tims words above. Voltages of coils, you only use 6V coils with electronic ignition on12V when you are sparking a twin, ie you have 2 off 6V coils (or you can use a 12V double ended coil). The only other time you would consider using a 6 V coil on a 12V system is if also you used a ballast resitor. This is a system of getting extra voltage at the coil when using an electric start and points as in 1960/70s cars and of course the MKIII Commando. You also need a specific starter solenoid to enable this trick. The Rotary uses it with electroinic ignition as well but there again that always was an odd ball machine!

As far as Richard Moss is concerned I believe I have directly given him enough information to go ahead with a 12V conversion with the alternator. As such this would allow retention of the lighting circuits as fitted for the previous dynamo. 6V alternator would not be advised as of course there is a new lights switch to find and the fitting of alternator switching wires.

Cheers Al Oz.

To cut a longer story (they all are) short, I've put a 1959 ES2 engine in a 1936 Model 18. The ES2 engine has a RM15 alternator (with as yet unknown performance) and a distributor.That is all I have.I want to get the bike working as soon as possible so that I can use it whilst we still have some summer (here's hoping!), and maybe look at possibilities for further development over the winter.I want to dovetail as simply with the existing electics without hacking it around too much, as I will at some point be returning the original engine (and magdyno) to service.I really need a wiring diagram to see what I have to do, and some idea of what coil etc I would need. Also I understand that alternator runs positive earth, and that the dynamo system was negative earth. Am I correct in understanding that there is no problem here in running the system as a negative earth as long as I get the wiring right throughout?Advice appreciated.

, it all comes as one kit that as all you need ,

and far better than Boyer or Pazon or anything else , on the market,

yours anna j

Previously anna jeannette Dixon wrote:

Previously Richard Moss wrote:

To cut a longer story (they all are) short, I've put a 1959 ES2 engine in a 1936 Model 18. The ES2 engine has a RM15 alternator (with as yet unknown performance) and a distributor.That is all I have.I want to get the bike working as soon as possible so that I can use it whilst we still have some summer (here's hoping!), and maybe look at possibilities for further development over the winter.I want to dovetail as simply with the existing electics without hacking it around too much, as I will at some point be returning the original engine (and magdyno) to service.I really need a wiring diagram to see what I have to do, and some idea of what coil etc I would need. Also I understand that alternator runs positive earth, and that the dynamo system was negative earth. Am I correct in understanding that there is no problem here in running the system as a negative earth as long as I get the wiring right throughout?Advice appreciated.

Hello Try out www.Electrexworld.co.uk Kit STK-100DC Fits BSA B50 so this should fit a Norton Alternator model ,as the Alternator are the same fittings So I would give them a call , you find there number on there Website . the thing about this is self generating with lights as well and no points to worries about

, it all comes as one kit that as all you need ,

and far better than Boyer or Pazon or anything else , on the market,

yours anna j

The above information from anna is NOT relevant to this original post so suggest ignore.

Al Osborn.