Rectifier problems - AJS M14 CSR (1966)

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
Groily
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Re: Rectifier problems - AJS M14 CSR (1966)

Post by Groily »

Not sure about that Steve S. Most alternators of our type are single phase not three phase. 3 phase will typically have an extra wire and the stators are a modern upgrade for RM24 as far as I know.
A Reg 1 and A Reg 6 rectifier/regulators are single phase.
Three phase items are available more expensively and are generally regarded as suitable for a lot of stop/start work in heavy traffic with lights on because their low speed output is better.
Better explanation here: http://www.norbsa02.freeuk.com/goffyelectrex.htm
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clanger9
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Re: Rectifier problems - AJS M14 CSR (1966)

Post by clanger9 »

Janet wrote:Just to add a comment from one who knows very little and may have misunderstood what I was told by someone who does know electrics very well, your alternator has to work harder when electrics have been upgraded to a 12 volt system so it needs to be in tip-top condition.
Hi Janet,

That's one way of looking at it. Its true, more volts = slightly more chance of insulation breaking down - though 6 or 12 volts makes almost no difference. However, 12 volts means half the current and a quarter of any heating effect from bad joints etc. So 12 volt systems are less stressful on connectors, joints, switches etc. That's why 12 volt systems tend to be more reliable - and is one reason why vehicles eventually settled on 12 volts rather than 6 (electric starting and better headlights were the main reasons...).

However, as you've found, there is absolutely nothing wrong with a 6 volt system when it is in good order.
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clanger9
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Re: Rectifier problems - AJS M14 CSR (1966)

Post by clanger9 »

Groily wrote:Not sure about that Steve S. Most alternators of our type are single phase not three phase. 3 phase will typically have an extra wire and the stators are a modern upgrade for RM24 as far as I know.
My '66 250CSR has 3 wires and is 3 phase. Charging output with an A Reg Three regulator/rectifier is excellent.
1989 Moto Morini Dart 350
1993 Ducati 750SS
Groily
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Re: Rectifier problems - AJS M14 CSR (1966)

Post by Groily »

That figures Clanger. As long as the parts are matched to suit, all should be well. The thing to avoid is hooking a three phase regulator to a single phase stator, which is the point I was trying to make!
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clanger9
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Re: Rectifier problems - AJS M14 CSR (1966)

Post by clanger9 »

Groily wrote:That figures Clanger. As long as the parts are matched to suit, all should be well. The thing to avoid is hooking a three phase regulator to a single phase stator, which is the point I was trying to make!
Agreed! Fig. 98 in the workshop manual shows the 250/350 Lightweight alternator is a 3 phase unit. It's not clear what was fitted to other models.
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Groily
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Re: Rectifier problems - AJS M14 CSR (1966)

Post by Groily »

I learn at least one new thing every day - good to learn it early in the morning then!
Quite forward-thinking to have gone that way so long ago I reckon.
So A Reg 3 or equivalent it has to be then - filed in grey matter for the future - as in 'in one ear and . . '
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