Thread: Motor Quiz
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Unread 23-12-2011, 11:25
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Re: Motor Quiz


Quote:
Originally Posted by sanddrag View Post
I arrived at my answer by a very different (and probably incorrect) method from the poster above. I figured motor constants for RPM/Volt and Oz-In/Amp, found how much current it would take to hold 60 oz-in at stall, considered the resistance of the motor's windings, then figured out how many volts it would need to hold 60 oz-in at stall, then I figured how many volts it would need to spin 3700 RPM at no load, then added those two voltages to arrive at my answer.
The above method is arithmetically identical to what Aren did:

current to hold "D" oz-in at stall = (D/B)*Istall

volts to hold "D" oz-in at stall = (D/B)*Istall*R = (D/B)*Istall*(12/Istall) = 12*(D/B)

volts to free-spin at "C" rpm = 12*(C/A)

adding these 2 gives:

"mystery volts" = 12*(C/A+D/B)