Ammeter - which way
On Wed, 29 May 2013 17:55:58 +0100, Harry Bloomfield
wrote:
After serious thinking Bill Wright wrote :
Harry Bloomfield wrote:
John Williamson presented the following explanation :
Harry Bloomfield wrote:
Remember the old type charge / discharge ammeters, where used a couple of
turns of cable which used to sometime be fitted to vehicles ? I have one
fitted to the tractor mower which is not marked + and - and I'm sure it
reads the wrong way. The needle goes left when on charge, I seem to
remember the norm is to move to the right.
Can anyone remember, before I take steps to correct it?
My Lard Roller ammeter is marked - to the left, + to the right, as have
all the others I've used. Has your tractor mower been converted from +ve
to -ve earth at some point?
No, it is not that old - I suspect the coil windings (2 turns) were simply
fitted the wrong way and it has bothered me since I got it.
Is it fitted upside down?
Bill
No, someone had wound it the wrong way when the tractor was built :-?
It uses a couple of turns of the main wire feed, wrapped around a metal
bracket at the back of the meter and the wire had a sticky label on it
showing the direction of flow.
I have rewound it so it reads charge with needle moving to the right.
Does it matter? As long as *you* know which way is charging.
--
Graham.
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