RC-Monster Forums - View Single Post - Trouble with MGM 22418

BrianG · 02.11.2008, 04:30 PM

Wow, those amp values sound wayyy off! AFAIK, the only two ways to measure current is measuring the voltage drop on a series-connected shunt, or use a inductive clamp. The clamp could be a coil of wire wrapped around one of the phases, but I doubt it. The shunt could introduce too much voltage loss (especially on a 224A ESC), so I don't see them doing that either.

The only other way I could see it working is if the software watches the battery voltage drop to calculate a very rough current value. But that requires some assumptions made about the output resistance of batteries and that they are all the same, which they are not.

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BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	02.11.2008, 04:30 PM Wow, those amp values sound wayyy off! AFAIK, the only two ways to measure current is measuring the voltage drop on a series-connected shunt, or use a inductive clamp. The clamp could be a coil of wire wrapped around one of the phases, but I doubt it. The shunt could introduce too much voltage loss (especially on a 224A ESC), so I don't see them doing that either. The only other way I could see it working is if the software watches the battery voltage drop to calculate a very rough current value. But that requires some assumptions made about the output resistance of batteries and that they are all the same, which they are not.