The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: Ewen on 22.09. 2021 20:17
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Thanks for the comments about Thorspark. My Goldflash is starting first kick almost every time at the moment, with the mag, but I have yet to try it after a decent run.
My next question. I am trying to determine if the electronic regulator fitted is for the correct earth polarity. These units are polarity sensitive aren't they? My bike is positive earth. Does anyone know what number should be on the regulator?
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G'day Ewen.
Both mine run DVR2's and set +ve and 12 volt to run the Boyer. When you purchase you select which + or -ve. Either can be 6 or 12v.
https://www.dynamoregulators.com/dvr2.php
On the plunger I have it hidden in the original Lucas reg case. Very happy after 25ish years use.
To answer your ?? what brand of unit do you have?
Cheers
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Rather depends what unit you actually have Ewen. As per Musky's '??'. Some types resist reverse hook-up no problem, others may not, so it certainly helps to know.
Some, like DVR2s, are marked P or N, and an additional clue is in the colour coding of the wires that go to earth - there's a red for + earth, or a black wire for - earth.
V Reg 2 units have gone through colour scheme wiring changes - recent ones have the same red for + earth and black for - earth as DVR2s, and Green, Brown and Yellow for F, A and D respectively. Earlier ones are a bit more complicated as neg earth ones use Red for the A lead and Black for earth (with White for F and Yellow for D), Pos earth ones have Black for the A lead and Red for the earth, with Blue for the field and Yellow for D. Both types havibg a red was presumably confusing, so they changed it!
Podtronics ones say on them 6-PE or 6-NE for Pos and Neg I think.
The cheap and cheerful ones Wassell sell are wired differently at the dynamo for + and - earth, so if you've got one of them and can't see from the box which way is earth, you can look at the wires under the dynamo cover: for Neg earth the 2 field coil wires that emerge from the inside of the dynamo will be connected one to F and the other to D; for Pos earth, one will be to F and the other to Earth.
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I will take it out and see if there is a number on my regulator. I know there is no brand name. It is a small aluminium block tapering where the bolt goes through with about 6 raised fins on it. I know that F and D on the generator go to F and D on the regulator just not sure about the positive and negative. The other 2 are ammeter and earth. Will check the wire colours Bill.
The reason I wondered was that I think when I tested output from the gen it was producing power when I had the meter negative to earth.. Thanks guys.
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Thanks Muskrat. Mine is a different brand. Yours is nice and clear. Mine only has a number. I will get back with a number and a photo. Thanks.
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Thanks Groily. If the gen produces power at my meter with the positive lead to earth and the negative lead to the bridged F and D then that side of things is set up for positive earth isn't it? Sorry if I'm stating the obvious.
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Thanks Groily. If the gen produces power at my meter with the positive lead to earth and the negative lead to the bridged F and D then that side of things is set up for positive earth isn't it? Sorry if I'm stating the obvious.
It is Ewen, if the meter shows positive volts in that config - and if you want Pos earth. (You were negative I think when you started?) A bulb alongside the meter is good, to be sure there's current sufficient to support loads, a 12v 21W brake light bulb is an easy test (and indicative enough usually) as it should illuminate easily. A headlight bulb might not be so good absent a battery in the circuit to warm it up a bit.
If you're still not sure of the polarity of your regulator though, it doesn't necessarily help you.
If the dynamo polarity were correct for the regulator, then a meter between the 'A' wire from the reg (to ammeter) and earth would show an output, which should be a 'regulated' one that stabilises with rpm. If there's nothing there, then it could be the polarity is wrong.
BUT, if the regulator is of a sort that won't handle a polarity reversal, it may already have suffered, or may be about to suffer if you run it up with the wrong polarity at the dyn. So it really would be good to figure out the spec of the regulator!
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good point on buggering up the reg bill, i managed that with my first one and on my 12v system i also found it needed at least a 9amp hour battery for reasons i don't understand, but never mind things have been working well for years now