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?

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

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?

--
Tciao for Now!

John.

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.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

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

On Wednesday, May 29, 2013 1:09:14 PM UTC+1, 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?

I think you're right, but you can have it how you like

On Wed, 29 May 2013 13:09:14 +0100, 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?

Fleming’s Left Hand Rule
http://www.le.ac.uk/se/centres/sci/selfstudy/mam12.htm


Oh wait, maybe it's the right hand rule
http://physicsed.buffalostate.edu/Se...ce/rhr/rhr.htm

hth ;-)

--
Graham.

%Profound_observation%

"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?

The usual orientation for a charge/discharge ammeter is with the quiescent
needle pointer resting at 12 O'clock (needle pivot at 6 O'clock); the
negative (-) discharge sector to the left (anticlockwise) and the positive
(+) charging sector to the right (clockwise).

Some ammeters (like yours) rather unhelpfully are not marked + and -.
However, they are usually colour-coded (blue or green sector for charging;
red sector for discharging), or annotated 'Charge' and 'Discharge' or simply
'C' and 'D'. Doesn't your ammeter have any of these legends or markings?

There are some versions of these ammeters designed to be mounted the other
way up, with the quiescent needle pointer resting at 6 O'clock. If your
ammeter is actually mounted upside-down (as has already been suggested),
then the needle would appear to read the wrong way. However, there must be
some lettering on your ammeter ('Amps' or 'A', or the manufacturer's name)
that would be inverted if the ammeter has been mounted the wrong way up.

When you say, "The needle goes left when on charge...", is that when
charging from an external battery charger, or when charging from an engine
mounted alternator? If the latter, then your alternator could be faulty and
not generating enough output to meet demand.

Check the wiring diagram (if you have one!) to see where in the circuit the
ammeter has been located. Also check the ammeter connections to see if it
has been connected reverse polarity.
--
Interloper

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.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

After serious thinking Interloper wrote :
"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?

The usual orientation for a charge/discharge ammeter is with the quiescent
needle pointer resting at 12 O'clock (needle pivot at 6 O'clock); the
negative (-) discharge sector to the left (anticlockwise) and the positive
(+) charging sector to the right (clockwise).

Some ammeters (like yours) rather unhelpfully are not marked + and -.
However, they are usually colour-coded (blue or green sector for charging;
red sector for discharging), or annotated 'Charge' and 'Discharge' or simply
'C' and 'D'. Doesn't your ammeter have any of these legends or markings?

There are some versions of these ammeters designed to be mounted the other
way up, with the quiescent needle pointer resting at 6 O'clock. If your
ammeter is actually mounted upside-down (as has already been suggested), then
the needle would appear to read the wrong way. However, there must be some
lettering on your ammeter ('Amps' or 'A', or the manufacturer's name) that
would be inverted if the ammeter has been mounted the wrong way up.

This one has the pivot at the bottom and points to 12. There are no
markings apart from 30 amp at either end and a 15amp marker. It kicks
left slightly (or did) when the starter solenoid engaged, then with the
engine running, would show around 5amps. No marks to indicate which
side was which at all.

When you say, "The needle goes left when on charge...", is that when charging
from an external battery charger, or when charging from an engine mounted
alternator? If the latter, then your alternator could be faulty and not
generating enough output to meet demand.

No, when the engine is running it went to the left - which seemed wrong
to me.


Check the wiring diagram (if you have one!) to see where in the circuit the
ammeter has been located. Also check the ammeter connections to see if it
has been connected reverse polarity.

Its in series with everything, apart from the starter main feed - just
the ignition circuit the interlocks and alternator really. The lights
rather oddly, are run from a separate output of the alternator.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

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.

%Profound_observation%

snip

It kicks
left slightly (or did) when the starter solenoid engaged, then with the
engine running, would show around 5amps. No marks to indicate which side
was which at all.

When you say, "The needle goes left when on charge...", is that when
charging from an external battery charger, or when charging from an
engine mounted alternator? If the latter, then your alternator could be
faulty and not generating enough output to meet demand.

No, when the engine is running it went to the left - which seemed wrong to
me.


But you also say that it deflected left when the solenoid engaged, which
would be correct for a left-side discharge indication, as the solenoid would
be drawing current - i.e. discharging the battery - at this time, as the
engine would not be running, and the alternator would not be attempting to
charge the battery. On cars that I have owned that have had an ammeter
fitted, the usual sequence of events would be a small deflection to the left
as the ignition was switched on, followed by a much larger deflection to the
left when the solenoid pulled in for starting, followed by a jump to the
right of 10 or more amps once the engine was running, fairly quickly
dropping back to 2 to 5 amps maintenance charge.

All seems very odd, if you ask me ... :-|

Arfa

Arfa Daily was thinking very hard :
snip

It kicks
left slightly (or did) when the starter solenoid engaged, then with the
engine running, would show around 5amps. No marks to indicate which side
was which at all.

When you say, "The needle goes left when on charge...", is that when
charging from an external battery charger, or when charging from an engine
mounted alternator? If the latter, then your alternator could be faulty
and not generating enough output to meet demand.

No, when the engine is running it went to the left - which seemed wrong to
me.


But you also say that it deflected left when the solenoid engaged, which
would be correct for a left-side discharge indication, as the solenoid would
be drawing current - i.e. discharging the battery - at this time, as the
engine would not be running, and the alternator would not be attempting to
charge the battery. On cars that I have owned that have had an ammeter
fitted, the usual sequence of events would be a small deflection to the left
as the ignition was switched on, followed by a much larger deflection to the
left when the solenoid pulled in for starting, followed by a jump to the
right of 10 or more amps once the engine was running, fairly quickly dropping
back to 2 to 5 amps maintenance charge.

All seems very odd, if you ask me ... :-|

Arfa

Sorry - now kicks to the left as the solenoid is engaged. Previously it
kicked to the right.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On 29/05/2013 15:18, 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
if you don't like the way it goes just reverse the wires