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A7 alternators again....
#6
(22-03-2022, 09:31 AM)andrew34ruby Wrote: The 168 watt output is hardly enough anyway. A pair of tungsten headlights and there's nothing left to power everything else.

They must be impressive headlights you're using? The Quartz Halogen headlamps on my special are 60W main beam 55W dip. So 120W for the pair. Add side & tail lights 20W and for a tourer or saloon a wiper motor @ perhaps 30W. That's pretty much the 168W output of the little alty. You may continue to be fortunate with your 60W A7 dynamo pushing out 120W as a 12V dynamo, but I have pretty much lost count of the ones I have seen where they have flung the solder off the armature commutator joints. The spindle I used in this conversion was one of those.

(21-03-2022, 11:23 PM)Ivor Hawkins Wrote: Now that looks neat, excuse my electro dyslexia but would that work with a six volt system?

well........... You could run it at 6V but it would give the regulator a really hard time. The main component in the regulator for a permanent magnet alty is a thing called a Zener Diode. Basically these have a set Zener Voltage 14.5 ish volts for a 12v system, or 7.8 ish volts for a 6 volt system. When the incoming voltage exceeds whatever the Zener voltage happens to be, the Zener diode sends it to earth, so immediately the voltage will drop below the Zener voltage and charge gets forwarded to the battery. Then when the voltage rises, once again it's earthed by the Zener diode. You can see why all the permanent magnet alty regulators have fins on them, have instructions that they should be in free air and/or should be bolted to a metal surface etc. It's because they are sinking power. Giving the alty setup above a quick test last night, the alty was pushing out almost 15V AC at not especially high revs; a regulator for a 6V system would function with this alty, but it would be working really hard and I think may well not live for very long.
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Messages In This Thread
A7 alternators again.... - by Stuart Giles - 21-03-2022, 11:08 PM
RE: A7 alternators again.... - by Ivor Hawkins - 21-03-2022, 11:23 PM
RE: A7 alternators again.... - by Bob Culver - 22-03-2022, 01:40 AM
RE: A7 alternators again.... - by Charles P - 22-03-2022, 09:14 AM
RE: A7 alternators again.... - by andrew34ruby - 22-03-2022, 09:31 AM
RE: A7 alternators again.... - by Stuart Giles - 22-03-2022, 09:55 AM
RE: A7 alternators again.... - by andrew34ruby - 22-03-2022, 02:17 PM
RE: A7 alternators again.... - by Stuart Giles - 23-03-2022, 10:50 PM
RE: A7 alternators again.... - by Ivor Hawkins - 24-03-2022, 03:22 PM
RE: A7 alternators again.... - by Bob Culver - 24-03-2022, 07:30 PM
RE: A7 alternators again.... - by Stuart Giles - 25-03-2022, 10:05 AM
RE: A7 alternators again.... - by Dave Mann - 25-03-2022, 12:07 PM
RE: A7 alternators again.... - by Hedd_Jones - 08-04-2022, 11:57 AM
RE: A7 alternators again.... - by Dave Mann - 08-04-2022, 01:53 PM
RE: A7 alternators again.... - by Ivor Hawkins - 08-04-2022, 01:57 PM
RE: A7 alternators again.... - by Stuart Giles - 08-04-2022, 02:01 PM

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