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Unread 15-07-2011, 00:43
philso philso is offline
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Re: Measuring motor current (anyone tried this?)

At work,we use larger versions of the LEM Hall-effect current sensors shown in the link below in the 3-phase motor controllers we manufacture. They will work down to DC and will have sufficient bandwidth to detect the PWM current into your motor. The one shown needs a +-15V supply. You may have to add a simple R-C filter on its output before you connect to your DVM. Many DVMs, especially the less expensive ones, will give wildly inaccurate readings if connected to a PWM signal.

http://search.digikey.com/scripts/Dk...me=398-1049-ND


I have seen clamp-on type DVM's by Kein Tools at Home Depot that claim to work down to DC but I have never tried them.

Phil