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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Andrew Borgogna on December 30, 2010, 12:39:10 PM
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I am assuming an amp meter would be a good tool to have and there may be other things that will help in determining how well the system is functioning. Any suggestions on what amp meter works best and what other equipment would be useful for evaluating system performance.
Andy
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I've been flying RC electric for years, and the piece of equipment that I lack is an ammeter with sufficient range!
You'll want a good* digital VOM. You want the voltmeter to make sure that you've got voltage where you're supposed to have voltage, and you want to be able to measure continuity to make sure that connectors are connected and wires are unbroken.
I really need to get or make an ammeter, though.
* You need good as in 'rugged', not necessarily good as in "the most accurate thing in the world". I use a Fluke 77 which is both, but that comes from my professional life, not because I needed it for electric flying.
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Tim,
You can get a very good DC amp meter that works well for our range from Sears a Craftsmen 400A AC/DC Clamp meter 82369. The cost is about $39. It has worked well for me also has built in volt meter and ohms reading. This is an important piece of equipment for an electric flyer to be able measure the amp load as you change prop load. This allows you to then estimate your battery capacity needed for a given amp load.
Best, DennisT
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Unless I have misunderstood the question, doesn't a Watt meter do this for you?
Mine displays Watts, Volts and Amps to several decimal places. I agree being able to connect a decent volt meter and/or Amp meter between various parts of the system is useful for chasing faults but for evaluating performance across different prop combinations etc other than a Watt meter and tach why would I need anything else? (Or buy an EagleTree data logger and in-flight info is also available - or get a CC Phoenix ICE ESC)
TTFN
John.
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I use an Astro Flight Super Whattmeter. It is available from many vendors (Tower, Hobby Lobby etc) for about $55. It reads voltage, watts and amps.
John
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I'll second John's comments. The Astro wattmeter is very useful. Meters made for what we are doing use a Hall effect device to measure current and are very accurate, and do not load the circuit.
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Hi Andy,
Here is a link to a very good Watt meter. This company is on the west coast and has good service and very good products. Their chargers and power supplies are excellent too.
http://www.progressiverc.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=135&category_id=12&option=com_virtuemart&Itemid=1
I agree with the others, a Watt meter and tach are all you really need for almost everything we do in ECL. If you want to monitor your cell V go to the "Tools and Accessories" on the site above and you will see some nice cell V monitors. Your LHS may have some in the car section? I have never found a need for an amp meter. Like John said, if you really want to see exactly what is going on with everything, then get the wonderful unit from Eagle Tree. Mine was a big help when I got started. It allowed me to get everything setup successfully in just a few flights. It is really valuable if you find a need to play around with different props and systems.
Happy New Year. :)
Regards, H^^
Rudy
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Of course, if you use any of the ICE ESC's, data logging is built in and VERY easy and accurate. I also have an Astro Wattmeter but it is only good for static loads and since we are well out of the "experimental" stage I do not have much of a use for it anynore...
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To all that suggested what I really want is a watt meter, yes you are correct. I come from 40 years in computer hardware engineering and we never thought in terms of watt meter we thought in terms of amp meter, volt meter (AKA VOM). Today we went flying and Larry Renger pulled out his neat little watt meter that also measures in volts and amps. It is perfect for what I want, he got his last year at the AMA convention and since that will be coming up next weekend and since I will be working our booth at the convention I will see if I can pick one up there. The only thing I would really like to have after that is an O-Scope so I can measure and monitor the output of the timer to see what the pulse width looks like for the rev control. Thanks again for all your help.
Andy
P.S. Rudy will you be at the convention? Hope you are and hope to see you. For everybody else, come by the Knights of the Round Circle booth, we will be the one and only Control Line booth at the convention :D.
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If you do any RC flying make up a Y harness and hook a servo in parallel to your timer. Then watch the arm position to see what the timer is doing.
Sorry about misdirecting you on the voltmeter -- I've got voltmeters running out of my ears and I'm a cheapskate, so I forget little niceties like going out and buying a Wattmeter instead of using two meters and a nest of wire to accomplish the same thing, for less money and a lot more fuss.
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Hi Andy,
Yes, I will be at the AMA Expo on Fri. I look forward to seeing you and Larry there. :-) I'm sure someone at the Expo will sell you a watt meter, and or a CC ICE ESC, Eagle Tree may be there too, and Hacker motors. ..... Oh heck, just bring a lot of money and some extra room in your car! n~
Warm Regards, H^^
Rudy
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Tim,
You can get a very good DC amp meter that works well for our range from Sears a Craftsmen 400A AC/DC Clamp meter 82369. The cost is about $39. It has worked well for me also has built in volt meter and ohms reading. This is an important piece of equipment for an electric flyer to be able measure the amp load as you change prop load. This allows you to then estimate your battery capacity needed for a given amp load.
Best, DennisT
I've been using one of these for eons, and the single notable advantage over any of the excellent WattMeters out there is that is clips on and clips off. Sometimes I watch the startup current after changing a prop, and quickly unclipo before takeoff.
Dean P.
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Thanks Dean, since its raining for the next few day I think I will take a ride over to Sears tomorrow and take a look. I too like the idea of a clamp on meter for all the reasons you stated. By the way batton down the hatches another big storm system is blowing in from the Pacific. After we get the rain you get the snow. I just put the sump pump out in the back to help move the water away from the house. ~^
Andy
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Thanks for the warning, Andy!
When at Sears, take care to note only some clamp-on ammeters are good for DC, not all of them.
The spec sheet should explicitly say that it works for DC.
take care,
Dean
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Andy,
The Sears Craftsmen 400A AC/DC Clamp meter 82369 is a DC clamp on.
Best, DennisT
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While at the AMA convention on Saturday I purchased some new test equipment. A watt/voltage/current meter, a servo tester which allows me to simulate a timer on the ground, and finally a monitor that measures the pulse width of the signal to the ESC. With this equipment I can monitor the power usage while measuring what size pulse width is required to give me the RPM needed on a given prop. I can use this information to determine the battery size I need. I want to do all this testing on the bench before installing the power package in the plane. Should be interesting.
Andy