EL013 ELECTRICAL
My 58 Venom had been stood a while and the Miller Regulator was seized. On stripping I discovered it was butchered beyond recovery. I decided to fit an electronic regulator from Britbits. I removed the cut out from the dynamo keeping the metal connectors together but insulated. The system is kept at 6v and negative earth. The resultant charge is at approx 6.7 volts but the current charges at up to 8 amps and above. Substituting with a Lucas RB regulator produces the same result – what have I done wrong??????? - Paul Martin 1/11/2002
It sounds like you are now "unregulated"
I'm no expert on these things, but when I bought my JG electronic regulator it
came with detailed instructions for preparing a Miller dynamo before it is
possible to connect it to the regulator (and I think the same is true if you
want to fit any other regulator to a Miller). It is correct that you have to
wire out (and ideally remove) the cut-out, but your new regulator would have
connectors to D and F on the dynamo (and A to the ammeter, and an Earth). An
original Miller shouldn't have an F, it had an S for shunt, also it connects
directly to the ammeter so you shouldn't have had connections available to match
the regulator's D, F and A.
The reason is that the Miller dynamo had an internal shunt winding next to the
field coil. It used a simpler(?) "cartridge" regulator in conjunction
with the shunt winding. If you have a look at your Red Book Service Manual you
should see both an exploded diagram and a theoretical diagram for the Miller DVR
and regulator. (Also if you look at the wiring diagrams on our site you'll see
that the regulator and ammeter connections are different between the Miller and
the Lucas set-ups.)
Your electronic regulator is like a Lucas regulator, not like the cartridge
Miller.
Your new regulator should have come with instructions for preparing either a
Miller DVR or a Lucas dynamo so I think the best approach is to chase up the
supplier or the manufacturer.
If you can't get any instructions try to work out what to do to suit the
connections on your regulator, but there's always a risk of getting it wrong.
Basically it is to identify your field coil wires (the Red Book gives the
colours of the wires and the resistance of the coils). One end becomes F, the
other end is D which also connects to the brush that is not connected to earth.
All other wires become redundant, and you now have the F and D to connect to
your new regulator.
If you want to take a chance and think your dynamo still has the original colour
wires and/or you have a digital multimeter, then the connections are normally:
(all this assumes you have removed the cut-out)
The Red and White wires are the ends of the field coil on a Miller DVR.
In case all your wires are now brown, the check is that this coil should have a
resistance of 4 ohms
Red is to become D, and must also be connected to the brush that is not earthed.
White is to become F
The shunt coil has green wires and a resistance of 7 ohm. Cut off or otherwise
disable these connections.
Make sure the earth brush has a good connection to earth.
Connect D & F to the new regulator, and connect the other wires on the
regulator to the ammeter and to earth (if you have an earth wire, or make sure
the body of the new regulator is well earthed)
BEFORE connecting a battery make absolutely sure it matches the polarity of the
regulator. The above assumes the dynamo is original Miller, still with negative
earth, and that your regulator is also designed for negative earth.
And after preparing the dynamo but before connecting the regulator, check that
the dynamo "motors" in the driven direction (see EL004). If it
doesn't rotate then it's broken, and if it rotates the wrong way then you need
to reverse the two field coil leads. - TW 1/11/2002
I had a chance to strip my dynamo, I am now even more confused. 2 red and 2
black wires emerge from the back of the field coil, no other wires or
colours.
1 red goes to 1 brush, 1 red & 1 black go to the centre insulated post and 1
black goes to the 3rd terminal which would have gone to the cutout via the brass
strips underneath, the cutout is removed the strips joined but held insulated
from the body, the strip continues to the 2nd brush. D I made the brush with 1
red wire, F the middle post with 1 red & 1 black. The regulator is a V REG
11 - Paul Martin 7/11/2002
Perhaps yours wasn't (or isn't now) a standard DVR..... the colour codes for
the wires are documented as I specified in both Velo books and in
the documentation I got with my JG regulator as Red and White, and Green &
Green. Maybe the coils have been rewired sometime.
Anyway, do you have a digital meter that can tell you which pair has a 4 ohm
resistance? That would give you the two ends of the field coil (unless it has
been replaced by one with a different resistance).
Then it's just a question of which way round to use them, which would be
determined by the 'motoring' test.
As above the connections should just be one end to D and the non-earthed brush,
and the other end is F.
No other connections - insulate all other wires and strips & keep them away
from D, F, earth and the brushes.
At the moment you have an extra Red going to F, an extra black going to the
brush which should be earthed, and your D Red isn't going to the brush....... -
TW 7/11/2002
I acquired a digital meter which allowed me to measure the values you
described and all became clear.
I cut out the resistance wiring leaving two red wires at 4 ohms, one end to the
earthed brush, the other becoming F and the other brush becoming D.
It works thanks. - PM 9/11/2002