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MG TD TF 1500 - Voltage output, 1952 TD

Hi All. How much voltage output should there be at idle(about 900 RPM) and at running/cruising speed on my 1952 TD? Can it vary slightly from specs? TIA
Cheers, Barry
C B Ryley

Have you read through Section N of the WSM? Bud
Bud Krueger (TD10855)

There should be no voltage output at idle... generators won't put out (so to speak) until about 2500 rpm....thats why alternators were born....

(this is using an ammeter as a guide anyway)
gblawson(gordon- TD27667)

Hi Barry,
My RPM has to be around 1400/1500 before I see any charging on the ammeter. It seems that the amount and duration of charge, depends on the battery level.

George
George Raham [TD4224]

Sorry, Gordon, but the generator puts out voltage just as long as the armature is turning inside of the magnetic field created by the pole pieces.

George, the ammeter is sorta' showing the difference between the battery voltage and the generator output voltage. When your ammeter is at zero it means that the generator output voltage is the same as the battery voltage.

[These are simplifications. May the experts please not jump down my throat. Bud]
Bud Krueger (TD10855)

I never measured at idle. But at cruising speeds you should see 14.4 volts at the battery. Thats if the regulator is adjusted properly.(lots of luck).

The voltages listed in the WSM are with no battery in the circuit. (Terminals A and A1 removed from the regulator and connected together.)

If you get more than 14.4 volts you will have to add water to the battery quite often because it will boil away.

To tell if the battery is full charged measure the voltage across the battery after it has rested all night and before you do anything else. Now you should get between 12.6 and 12.8 volts. Or better yet measure the acid with a hygrometer should see 1280 to 1310.
Cheers,
Bob
Bob Jeffers

I suppose I should have written 'charge' instead of output....thats why I added the 'ammeter' bit.... I noticed just the day before the posting that I didn't get above the + until about 2000 rpm or so....
gblawson(gordon- TD27667)

Too much Monty Python in my youth ...I have this vision of Bob flying down a curvey road @ 65MPH hanging over the cowl taking this measurment with a volt/ohm meter! LOL
Cheers,
David
David Sheward

David S. Nothing quite so dramatic, I use the trouble light jacks on the dash(facia)of my TD.
Cheers,
Bob
Bob Jeffers

David, I had thought of having a buddy, with the hood/bonnet removed, hanging on to the left side Rad support bar at 65MPH. Then holding a voltmeter and screwdriver and at 20C, if it was required, adjusting the regulator. But, darn, I was concerned about my safety.
Thanks to everybody for all the great information.
Cheers,
Barry, who might see you in mid September, back east at the large meet.
C B Ryley

This thread was discussed between 17/07/2011 and 18/07/2011

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