[Mgs] 54 TF ammeter question

[PaulHunt73]

The ammeter indicates the amount of current flowing.  If the cars electrics and battery are taking more than the dynamo can provide, then the ammeter will be showing a discharge.  If the engine revs are increased and this results in an increase in output from the dynamo, then the ammeter will indicate less of a discharge, and may move to show a charge.  Similarly if more things are switched on, then if a charge was being indicated before, that may reduce or it may become a discharge.  It all depends on how much current the cars electrics and battery are taking, compared with the dynamo output at the time.

Without the engine running i.e. no output from the dynamo switching anything - lights or ignition - on should show a discharge.

One needs to repolarise the dynamo after switch polarity or it will not charge.  If the polarity was switched between connecting the ammeter one way, then the other, and wasn't repolarised in between, then that would explain why the ammeter moved in the same direction both times.  

But if the ammeter connections were reversed independently of switching the polarity, as seems likely, then there is some other reason why it indicates in the same direction as before reversing the connections.  Like the connections weren't actually reversed, of it was charging before but isn't now.  If the engine wasn't even run, just turned on ignition or lights, then the connections weren't actually reversed.

PaulH.


  ----- Original Message ----- 
    When engine revs increase, does the ammeter needle move farther?
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