Classic cars forum & vehicle restoration.

[jimforrest]

Hello people - new chap here. Although I am a Jaguar man (I have three- 2x XJ8's and an XK8), I am helping a friend renovate/restore a 1934 Daimler LQ. She's a classic 'old Rolls' shape with a 6 cylinder longstroke engine, spare wheels on the running boards, and a Wilson pre-select gearbox.

Most of the chassis work is complete now, and the engine is also running (it was rebuilt 20 years ago and then immediately put in storage!) However, it has a peculiar dynamo design that we'd like a little help on. The dynamo is driven by a three belt pulley and bolted to the engine with the water pump driven off the rear of the armeture shaft. Inside it has only two brushes and they are spaced at approx 90 degrees. We have only either seen 2 x 180 degrees, or a three brush system. Can anyone point us towards any information on this design of generator? I can't find anything on the subject so we don't know how to wire it up. (The electrics are 12V by the way).

The car's wiring has mostly been removed (by previous owner), but the voltage control box is still fitted on the bulkhead. However, it is beyond salvage! Can anyone say if this two brush system could be connected to a modern solid state regulator hidden inside the old regulator casing?

[peter scott]

Hi Jim,

I haven't come across a dynamo with this brush arrangement either and I don't know why it was used but I'd be inclined to assume that it is nothing more than a strange way of wiring the commutator. I would just try connecting its armature to the D terminal and field to the F terminal of a simple CVC regulator such as RB95 and see whether it does sensible things on the ammeter.

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[jimforrest]

Last time someone said - 'I'd just try ...... ' I spent 3 hours in A&E!
Mind you - not a lot of options really. I'll tell my friend to do it (hehe).

[Rick]

Are no original handbooks still around for that model? Does the generator have any maker's markings, and/or model numbers, on it?

RJ
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[DM]

"Modern Motor Repair and Overhauling" book lists the dynamo as -

Model AT101
12V
12 amps at full output speed
Cut in speed 530 rpm
Full output speed 1250 rpm
Earth return
Anticlockwise rotation

[peter scott]

It looks as if the 90 degree brush arrangement stems from having previously been a 3 brush dynamo. Just ignore this and connect it to a normal field regulator.

Peter

Lucas dynamo from a 1934 four cylinder BSA 3 wheeler converted to 2 brush and 12v operation


_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[jimforrest]

Thanks chaps - but the anti-clockwise rotation is not correct. See the pics -





'A normal field regulator' - do you mean from an ordinary 180 deg two brush dynamo?

[jimforrest]

It's worth noting that Daimler built (primarilly) lorries and busses at that time. So this is probably a bus engine!

[peter scott]

[jimforrest]

Cheers Peter. We'll give it a try. My friend is off to Beaulie autojumble (next month I think) so he can try to pick up a 'period' regulator.

[captain bobo]

The arrangement that you show is the same as the arrangement on my 1937 Daimler 15 Sports Saloon. I believe that all Daimler 15's, which were built from 1934 to 1937, had this arrangement of driving the dynamo via the water pump.

By now you will, I suspect, have discovered that the wiring is relatively straightforward as a 2 brush system.

Best wishes, Dave B
_________________
1937 Daimler 15 Mulliner Sports Saloon & 1969 Daimler V8 250 Saloon

[captain bobo]

Whoops! I meant "drive the water pump via the dynamo".

Dave B
_________________
1937 Daimler 15 Mulliner Sports Saloon & 1969 Daimler V8 250 Saloon