23-05-2021, 05:34 PM
(This post was last modified: 23-05-2021, 05:54 PM by John Cornforth.)
Well that's a puzzle. The Ammeter is a very simple thing, just a magnetised piece of metal (pole piece) with a pointer which reacts to the magnetic field created by the current in a short piece of conductor. Hard to see how the magnetism of the metal could have increased.
These things are hardly the last word in accuracy, but your sounds like it is miles off.
I don't suppose "someone" has combined the innards of a 10 A meter with the scale of a 20A one ?
Or maybe the needle works against a light spring which has weakened/broken ?
This article may shed some light: http://www.da7c.co.uk/technical_torque_a...r%202.html
These things are hardly the last word in accuracy, but your sounds like it is miles off.
I don't suppose "someone" has combined the innards of a 10 A meter with the scale of a 20A one ?
Or maybe the needle works against a light spring which has weakened/broken ?
This article may shed some light: http://www.da7c.co.uk/technical_torque_a...r%202.html