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Feb 17, 2003, 11:42 AM
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William A's Avatar
I've got the Craftsman meter and a AF Watt meter.

When used together on a 40 amp application, they're within .1 (1/10) of an amp of each other.

Close enough for me
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Feb 17, 2003, 12:07 PM
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Oh just Great!!


I just bought a new brushless motor and esc 2 days ago and now I 'm off to sears for a new meter. Well there ain't no dust gatherin' on my credit card, or under my feet and I'm helpin' the economy. Beside all that I get a new tool in my quiver. Thanks (Really)
Feb 17, 2003, 12:35 PM
Registered User
William A's Avatar
Glad to help with the 'dusting'.
Actually, I'm about 2 steps away from ordering another myself.
The one I've got rides in my lunch box so I have it available for both work and home.
Feb 17, 2003, 01:50 PM
f5b-uk
Mike Seale's Avatar
Quote:
Originally posted by William A
I've got the Craftsman meter and a AF Watt meter.

When used together on a 40 amp application, they're within .1 (1/10) of an amp of each other.

Close enough for me
A clamp meter is something I feel I need but the cheapest I've seen this side of the pond is more than 100 GBP. I can get cheaper but then it won't do DC Amps - not a lot of use. Anyone know of a website where I can order this or a similar meter for 50 USD?

Mike
Dorset UK
Feb 17, 2003, 07:32 PM

DC?


Wiliam:

Very intersting!!! Does the inductive pick up on your Crastsman meter work on DC??

I was under the impresion that inductive pick ups worked when there was AC present only
Feb 18, 2003, 01:38 AM
Registered User
William A's Avatar
Quote:
Does the inductive pick up on your Crastsman meter work on DC??
Yes.

Quote:
I was under the impresion that inductive pick ups worked when there was AC present only
Yes, I was too, but from what I'm being told they have been around for a while.
Feb 18, 2003, 06:22 AM
St Charles Flyer

Hall Device?


In looking at the picture, my guess is that a hall sensor is used to measure the magnetic field produced by the DC or AC current. There is a DC Amp zero adjustment on the meter. My experience with hall sensors is that they can match them pretty well as to response but the zeros tend to differ.

I'm impresssed by the low cost of the meter and its capabilities. Though the Sears site really does not go into the accuracy specs for the meter, but the quote from William A
Quote:
I've got the Craftsman meter and a AF Watt meter. When used together on a 40 amp application, they're within .1 (1/10) of an amp of each other.
says it can't be too bad. Maybe this hobby is getting less expensive every day? Then again, there seems to be an exponential curve for the introduction of new toys.

STL
Feb 18, 2003, 10:09 AM
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Got Craftsman amp meter last night.


Couldnít resist the thought that there was a tool that I didnít own so off I flew and after waiting patiently for a set of AAA batts to charge for me (drumming my fingers on the charger) I went out to confirm everything William has said.
This thing is a jewel!!. No more disconnecting leads to get in the circuit, just clamp it on, zero the digital read out and crank up the motor.
Small size easily fits in my flight box. Being able to check continuity, voltage and amperage with one tool is great. All it needs is a built in tach and life would be perfect. Hey I need to leave some hedge room for a new tool eh? I was pleased with the price and the selection, this is a great find and I highly reccommend it. Thanks William. It is a must have for any serious electric enthusiast.
Happy Gator
Feb 18, 2003, 02:44 PM
Space Coast USA
hoppy's Avatar
You can check my calculations....
Use a 4" piece of 16 gauge bare copper wire. Solder two small wires to the bare copper wire exactly 3" apart and minimize the amount of solder within that 3". Use these wires to connect your multimeter set to mv. You can solder connectors on the ends to mate to your power source and motor.
I=e/r r = 0.001 ohm 1 amp x .001ohm = 0.001V or 1 mv.
So each mv = 1A.

Ok guys, check the math

hoppy
Feb 18, 2003, 03:18 PM
Registered User
Correct.
Feb 19, 2003, 07:20 AM
Registered User

Cheap amp meter


Would one of these meters work OK for our purposes (keeping ESCs and motors from self destructiong)? http://www.action-electronics.com/panelmeters.htm I would think they would. Couldn't one just hook a positive and a negative wire to the back of the meter, then touch these to to the back lugs of a running motor? What do you all think? RCNutt
Feb 19, 2003, 09:26 AM
St Charles Flyer

Cheap Amp Meter


rcnutt

Quote:
Couldn't one just hook a positive and a negative wire to the back of the meter, then touch these to to the back lugs of a running motor?
I get a little worried about the way you said this. An ammeter must be connected in series with the circuit rather than in parallel (across) with the circuit. Touching an ammeter across the motor terminals could allow the smoke trapped inside the meter during manufacture to escape.

Relating it to water, an ammeter is like your water meter. It must be in the line to measure not across the line. It measures flow.

Otherwise, an analog meter will work just as the higher cost digital meter. They have jewel bearing for the needle and are not as rugged as a digital meter. Actually analog displays (meters) register on your mind faster than the digital displays. Oops, it's going off scale is a gut reaction.

STL
Feb 26, 2003, 11:42 AM
Registered User
Quote:
Originally posted by Mike Seale
A clamp meter is something I feel I need but the cheapest I've seen this side of the pond is more than 100 GBP. I can get cheaper but then it won't do DC Amps - not a lot of use. Anyone know of a website where I can order this or a similar meter for 50 USD?
Mike,

I'm sure you've already found the site since it's been a few days but, in case you or anyone else has not, go to www.sears.com and do a search for "clamp ammeter pocket" without the quotes. I don't know how Sears handles international shipping.

Bill
Feb 26, 2003, 12:36 PM
f5b-uk
Mike Seale's Avatar
Quote:
Originally posted by wmsvirsky
pocket" without the quotes. I don't know how Sears handles international shipping.

Bill
Thanks,

I did find the site and the answer is that they do not handle international shipping I'll have to wait till later in the year when my father should be able to bring one home for me.

Mike
Feb 27, 2003, 07:26 PM

Re: Cheap Amp Meter


Quote:
Originally posted by STL.SF
rcnutt



Touching an ammeter across the motor terminals could allow the smoke trapped inside the meter during manufacture to escape.


STL
Now that is funny stuff...


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