I think Larry once explained why the amps get cut in half, but I forgot.
I have an amp meter installed in line between the alternator and the
battery switch. Last weekend I had a borrowed Fluke clamp meter. When I
put the clamp on the line coming out of the alternator it read exactly
half of what the in line amp meter was reading. Why is that?

Stephen

On Thu, 05 May 2011 10:02:55 -0700, Stephen Trapani
wrote:

I think Larry once explained why the amps get cut in half, but I forgot.
I have an amp meter installed in line between the alternator and the
battery switch. Last weekend I had a borrowed Fluke clamp meter. When I
put the clamp on the line coming out of the alternator it read exactly
half of what the in line amp meter was reading. Why is that?


Sounds to me like an inaccuracy in one of the meters. Do I
understand correctly that you are clamping the Fluke around the one
and only wire delivering power from the alternator? Do you have the
Fluke switched to DC amps, and on the correct scale?

On 5/5/2011 10:43 AM, Wayne B wrote:
On Thu, 05 May 2011 10:02:55 -0700, Stephen Trapani
wrote:

I think Larry once explained why the amps get cut in half, but I forgot.
I have an amp meter installed in line between the alternator and the
battery switch. Last weekend I had a borrowed Fluke clamp meter. When I
put the clamp on the line coming out of the alternator it read exactly
half of what the in line amp meter was reading. Why is that?


Sounds to me like an inaccuracy in one of the meters. Do I
understand correctly that you are clamping the Fluke around the one
and only wire delivering power from the alternator?

Yes.

Do you have the
Fluke switched to DC amps, and on the correct scale?

Yes. I'll ask the guy who loaned me the Fluke to be sure.

Stephen

On 5/5/2011 12:44 PM, Stephen Trapani wrote:
On 5/5/2011 10:43 AM, Wayne B wrote:
On Thu, 05 May 2011 10:02:55 -0700, Stephen Trapani
wrote:

I think Larry once explained why the amps get cut in half, but I forgot.
I have an amp meter installed in line between the alternator and the
battery switch. Last weekend I had a borrowed Fluke clamp meter. When I
put the clamp on the line coming out of the alternator it read exactly
half of what the in line amp meter was reading. Why is that?


Sounds to me like an inaccuracy in one of the meters. Do I
understand correctly that you are clamping the Fluke around the one
and only wire delivering power from the alternator?

Yes.

Do you have the
Fluke switched to DC amps, and on the correct scale?

Yes. I'll ask the guy who loaned me the Fluke to be sure.

I called Fluke. The setting I used was supposed to give me straight DC
current. So...mystery NOT solved. Where's that damned Larry when you
need him???

Stephen

"Stephen Trapani" wrote in message
...
On 5/5/2011 12:44 PM, Stephen Trapani wrote:
On 5/5/2011 10:43 AM, Wayne B wrote:
On Thu, 05 May 2011 10:02:55 -0700, Stephen Trapani
wrote:

I think Larry once explained why the amps get cut in half, but I
forgot.
I have an amp meter installed in line between the alternator and the
battery switch. Last weekend I had a borrowed Fluke clamp meter. When I
put the clamp on the line coming out of the alternator it read exactly
half of what the in line amp meter was reading. Why is that?


Sounds to me like an inaccuracy in one of the meters. Do I
understand correctly that you are clamping the Fluke around the one
and only wire delivering power from the alternator?

Yes.

Do you have the
Fluke switched to DC amps, and on the correct scale?

Yes. I'll ask the guy who loaned me the Fluke to be sure.

I called Fluke. The setting I used was supposed to give me straight DC
current. So...mystery NOT solved. Where's that damned Larry when you need
him???

Stephen



An alternator puts out Alternating Current which runs through a bridge
rectifier which rearranges it to pulsed Direct Current. Pulsed DC is not
real DC. That meter will only read right on loads from the battery. Try it
on a lead from the battery to the load and I bet it then reads correctly.

Larry wasn't as smart as me. . .

Wilbur Hubbard

On Fri, 06 May 2011 08:32:12 -0700, Stephen Trapani
wrote:

Do you have the
Fluke switched to DC amps, and on the correct scale?

Yes. I'll ask the guy who loaned me the Fluke to be sure.

I called Fluke. The setting I used was supposed to give me straight DC
current. So...mystery NOT solved. Where's that damned Larry when you
need him???

Unfortunately Larry has been MIA for a while now.

You could try him he larryw4csc -at- gmail -dot- com

Wilbur is correct that the alternator puts out pulsed DC but the Fluke
should average that out to the correct value. The load of the battery
also acts as a giant capacitor to further smooth the output.

I think at this point you'll need to try temporarily replacing your
other ammeter with a high quality shunt type unit and see what you
get. As I understand it the output of your alternator goes directly
to one side of your ammeter, and from the other side, directly to the
battery?

On 5/6/2011 1:40 PM, Wayne B wrote:
On Fri, 06 May 2011 08:32:12 -0700, Stephen Trapani
wrote:

Do you have the
Fluke switched to DC amps, and on the correct scale?

Yes. I'll ask the guy who loaned me the Fluke to be sure.

I called Fluke. The setting I used was supposed to give me straight DC
current. So...mystery NOT solved. Where's that damned Larry when you
need him???

Unfortunately Larry has been MIA for a while now.

You could try him he larryw4csc -at- gmail -dot- com

Wilbur is correct that the alternator puts out pulsed DC but the Fluke
should average that out to the correct value. The load of the battery
also acts as a giant capacitor to further smooth the output.

I think at this point you'll need to try temporarily replacing your
other ammeter with a high quality shunt type unit and see what you
get. As I understand it the output of your alternator goes directly
to one side of your ammeter, and from the other side, directly to the
battery?

Yes, but from the other side of the ammeter directly to the battery
_switch_. So the Fluke was around the wire heading to the ammeter.

Stephen

On 5/6/2011 1:54 PM, Stephen Trapani wrote:
On 5/6/2011 1:40 PM, Wayne B wrote:
On Fri, 06 May 2011 08:32:12 -0700, Stephen Trapani
wrote:

Do you have the
Fluke switched to DC amps, and on the correct scale?

Yes. I'll ask the guy who loaned me the Fluke to be sure.

I called Fluke. The setting I used was supposed to give me straight DC
current. So...mystery NOT solved. Where's that damned Larry when you
need him???

Unfortunately Larry has been MIA for a while now.

You could try him he larryw4csc -at- gmail -dot- com

Wilbur is correct that the alternator puts out pulsed DC but the Fluke
should average that out to the correct value. The load of the battery
also acts as a giant capacitor to further smooth the output.

I think at this point you'll need to try temporarily replacing your
other ammeter with a high quality shunt type unit and see what you
get. As I understand it the output of your alternator goes directly
to one side of your ammeter, and from the other side, directly to the
battery?

Yes, but from the other side of the ammeter directly to the battery
_switch_. So the Fluke was around the wire heading to the ammeter.

Wait! I take it back! The wire coming from the ammeter did not go
directly to the battery switch, it went to the solenoid on the starter.

Stephen

On Fri, 6 May 2011 11:47:56 -0400, "Wilbur Hubbard"
wrote:

"Stephen Trapani" wrote in message
...
On 5/5/2011 12:44 PM, Stephen Trapani wrote:
On 5/5/2011 10:43 AM, Wayne B wrote:
On Thu, 05 May 2011 10:02:55 -0700, Stephen Trapani
wrote:

I think Larry once explained why the amps get cut in half, but I
forgot.
I have an amp meter installed in line between the alternator and the
battery switch. Last weekend I had a borrowed Fluke clamp meter. When I
put the clamp on the line coming out of the alternator it read exactly
half of what the in line amp meter was reading. Why is that?


Sounds to me like an inaccuracy in one of the meters. Do I
understand correctly that you are clamping the Fluke around the one
and only wire delivering power from the alternator?

Yes.

Do you have the
Fluke switched to DC amps, and on the correct scale?

Yes. I'll ask the guy who loaned me the Fluke to be sure.

I called Fluke. The setting I used was supposed to give me straight DC
current. So...mystery NOT solved. Where's that damned Larry when you need
him???

Stephen



An alternator puts out Alternating Current which runs through a bridge
rectifier which rearranges it to pulsed Direct Current. Pulsed DC is not
real DC. That meter will only read right on loads from the battery. Try it
on a lead from the battery to the load and I bet it then reads correctly.

Larry wasn't as smart as me. . .

Wilbur Hubbard


Ahhh Willie-boy. Do you sit up nights studying or are you naturally
this stupid?

DC electricity is a form of electricity where the electrons all move
in the same direction ( from an area of negative (-) charges to an
area of positive (+) charges).

AC electricity is a form of electricity in which the polarity reverses
and therefore electrons flow one way during half the cycle and the
other way during the other half.

Pulsed DC is simply a DC current that is switched on and off (pulsed)
it IS NOT A NEW FORM OF ELECTRICITY.

An alternator produces AC electricity and an automotive type
"alternator" produces DC electricity by converting or rectifying the
AC current into DC current. It does this by using "diodes" which are a
little two legged gizzy that can be thought of as one way electrical
valves. Connected one way they conduct only during the positive
portion of the AC wave and if connected "backward" they conduct during
the negative portion.

A bridge rectifier is simply 4 diodes with two connected to conduct
during the positive portion of each side of the alternating wave form
and two conducting during the negative. This gives the smoothest DC
form possible in a simple DC circuit from an auto type alternator.

Now, if you connect the positive lead of your meter to the alternator
output connection and the negative lead to ground you will read the
output voltage of the alternator, not some idiotic and fictitious
Pulsed DC that Willie-boy talks about.

Why? Because while the DC current is actually fluctuating it is doing
so fast that you meter can't react quickly enough and so reports the
correct effective voltage. Most DC stuff doesn't care what it gets as
long as it all comes from the same direction.

When the pulsed (so fast you can't measure it with your meter) DC
reaches the battery it charges it just as though it was pure, filtered
DC.

So. If you are interested in a DC circuit stick your meter on it and
read the voltage, don't get all wound up in pulsed DC and all the
other weird things that Willy-boy comes up with.

Amps and volts:
Power is measured in Watts which are the amperage used in the circuit
times the voltage in the circuit. If you have a 12 volt light bulb and
it draws 2 amp then you have a (121 x 2) 24 watt light. Change the
amperage or the voltage and the power (Watts) change.

12 Volts X 4 amps = 48 watts
1 V X 4 A = 4 watts.
1000 V X 0.048 A = 48 watts.
and so on.
Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

"Bruce in Bangkok" wrote in message
...
On Fri, 6 May 2011 11:47:56 -0400, "Wilbur Hubbard"
wrote:

"Stephen Trapani" wrote in message
...
On 5/5/2011 12:44 PM, Stephen Trapani wrote:
On 5/5/2011 10:43 AM, Wayne B wrote:
On Thu, 05 May 2011 10:02:55 -0700, Stephen Trapani
wrote:

I think Larry once explained why the amps get cut in half, but I
forgot.
I have an amp meter installed in line between the alternator and the
battery switch. Last weekend I had a borrowed Fluke clamp meter. When
I
put the clamp on the line coming out of the alternator it read
exactly
half of what the in line amp meter was reading. Why is that?


Sounds to me like an inaccuracy in one of the meters. Do I
understand correctly that you are clamping the Fluke around the one
and only wire delivering power from the alternator?

Yes.

Do you have the
Fluke switched to DC amps, and on the correct scale?

Yes. I'll ask the guy who loaned me the Fluke to be sure.

I called Fluke. The setting I used was supposed to give me straight DC
current. So...mystery NOT solved. Where's that damned Larry when you
need
him???

Stephen



An alternator puts out Alternating Current which runs through a bridge
rectifier which rearranges it to pulsed Direct Current. Pulsed DC is not
real DC. That meter will only read right on loads from the battery. Try it
on a lead from the battery to the load and I bet it then reads correctly.

Larry wasn't as smart as me. . .

Wilbur Hubbard


Ahhh Willie-boy. Do you sit up nights studying or are you naturally
this stupid?

DC electricity is a form of electricity where the electrons all move
in the same direction ( from an area of negative (-) charges to an
area of positive (+) charges).

AC electricity is a form of electricity in which the polarity reverses
and therefore electrons flow one way during half the cycle and the
other way during the other half.

Pulsed DC is simply a DC current that is switched on and off (pulsed)
it IS NOT A NEW FORM OF ELECTRICITY.

An alternator produces AC electricity and an automotive type
"alternator" produces DC electricity by converting or rectifying the
AC current into DC current. It does this by using "diodes" which are a
little two legged gizzy that can be thought of as one way electrical
valves. Connected one way they conduct only during the positive
portion of the AC wave and if connected "backward" they conduct during
the negative portion.

A bridge rectifier is simply 4 diodes with two connected to conduct
during the positive portion of each side of the alternating wave form
and two conducting during the negative. This gives the smoothest DC
form possible in a simple DC circuit from an auto type alternator.

Now, if you connect the positive lead of your meter to the alternator
output connection and the negative lead to ground you will read the
output voltage of the alternator, not some idiotic and fictitious
Pulsed DC that Willie-boy talks about.

Why? Because while the DC current is actually fluctuating it is doing
so fast that you meter can't react quickly enough and so reports the
correct effective voltage. Most DC stuff doesn't care what it gets as
long as it all comes from the same direction.

When the pulsed (so fast you can't measure it with your meter) DC
reaches the battery it charges it just as though it was pure, filtered
DC.

So. If you are interested in a DC circuit stick your meter on it and
read the voltage, don't get all wound up in pulsed DC and all the
other weird things that Willy-boy comes up with.

Amps and volts:
Power is measured in Watts which are the amperage used in the circuit
times the voltage in the circuit. If you have a 12 volt light bulb and
it draws 2 amp then you have a (121 x 2) 24 watt light. Change the
amperage or the voltage and the power (Watts) change.

12 Volts X 4 amps = 48 watts
1 V X 4 A = 4 watts.
1000 V X 0.048 A = 48 watts.
and so on.
Cheers,

Bruce
(bruceinbangkokatgmaildotcom)



Hey moron! Forget about voltage - we're discussing measuring amperage in
this thread.

You have proven how dumb you are again, Bruce. Your talk about connecting a
volt meter in parallel is correct but an amp meter does not connect to
positive and negative leads. You'd burn it out doing that. Amp meters
connect in series. The type of amp meter we're discussing here in this
thread doesn't connect at all. It consists of a mechanical jaw your run the
insulated wire through. It reads the magnetic field and converts it into a
current reading. (amps) So, why the heck are you trying to misdirect with
your voltage nonsense?

In a bridge rectified circuit, if you observe it on an oscilloscope, it will
have a sine wave that is 'chopped' looking - not smooth. This type of sine
wave doesn't produce as strong a magnetic field as a conventional smooth
sine wave. A loop type amp meter will come up with an incorrect amp reading
because of the rectified circuit that simply turns the alternating current
so it all flows in one direction. The only problem with that is the short
periods when the A/C turns around it stops completely for a finite period of
time. The finite period of time is not eliminated by the rectifier. So you
have a period of direct current then you have a short period of no current
then a period of direct current and then no current. The magnetic field is
not constant but rises and falls. The loop amp meter fails to read it
because it's not calibrated to correctly measure this type of current that
is not steady.

Don't you ever get tired of me proving you don't know anything?


Wilbur Hubbard