HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 06, 2006, 04:59 PM
Registered User
Joined Jan 2006
20 Posts
Question
measure wattage draw at home w/ voltmeter?

If I've got a ready-to-fly plane with power system installed, is there a way to measure the actual wattage draw while on the ground? I'm pretty sure the answer to this question is "yes" but I'm not sure exactly how to do it.

I've heard of the whattmeter but don't have one... I'm mostly literate with using a standard voltmeter... is measuring the power draw as simple as hooking up the battery and measuring the voltage drop and amp draw across the two battery terminals?

Maybe asked another way is "if all I have is a flight-ready airplane and a voltmeter, how do I make this happen?"
ljwobker is offline Find More Posts by ljwobker
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 06, 2006, 05:01 PM
-plancks only-
Franck's Avatar
Pays Bas
Joined Oct 2001
1,077 Posts
http://www.rcgroups.com/forums/showt...ighlight=shunt

Regards,

Franck
Franck is online now Find More Posts by Franck
Reply With Quote
Old Feb 06, 2006, 05:23 PM
Registered User
Staffs, UK
Joined Nov 2003
10,346 Posts
To measure watts you need to measure current AND voltage at the same time. This takes either a wattmeter or TWO voltmeters.

But I guess you really want to measure the current draw in which case the shunt and a voltmeter that reads down to millivolts will do it.

Steve
slipstick is offline Find More Posts by slipstick
Reply With Quote
Old Feb 06, 2006, 07:44 PM
Registered User
peterp1964's Avatar
Joined Oct 2005
659 Posts
here's my "watt meter"...the ammeter is 1A full scale but with a shunt
it can measure either 10 A max (shunt is 14 inches of 18awg copper
wire) or 20 A max (shunt of 28 inches of 18awg copper wire) - see
pic of backside. I've used the multimeter to verify the new scales. The
voltmeter is 0-15 V. Don't forget the fuse !

Total cost: about 25 bucks if you buy all you see in the picks.

Peter
peterp1964 is offline Find More Posts by peterp1964
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
How to charge batteries at home Patrick Plawner Beginner Training Area (Aircraft-Electric) 16 Jun 20, 2002 04:49 PM
Can you Zap your own cells at home?? jet jock Electric Ducted Fan Jet Talk 5 Jan 21, 2002 03:12 PM
3rd attempt at home built LuckyArmpit Beginner Training Area (Aircraft-Electric) 10 Nov 09, 2001 09:01 PM
Corsair project half completed -- don't try this at home! Neil Morse Electric Plane Talk 2 Sep 10, 2001 04:43 PM
Charity begins at home Mark Wood Life, The Universe, and Politics 33 Jul 17, 2001 07:30 PM