Here's a big shot in the dark:

Has anyone out there used Fairchild's FCM8201/2 Sinusoidal BLDC Motor Contr=
ollers?
I have gotten a driver for a 75W fan motor working using the FCM8201, but s=
ome of it's operation makes no sense to me and Fairchild and the web have t=
hus far not provided enlightenment.

The motor is delta-wound motor with 120 degree hall commutation. =A0In orde=
r to run the motor I have to slip the commutation 120 degrees from what is =
labelled i.e. with the halls connected correctly (a-a,b-b, c-c) the motor l=
eads must be connected (Driver-Motor) U-V, V-W, W-U. =A0And the angle-shift=
 function of the chip, while shifting to the sinusoidal drive mode ok, seem=
s to have the opposite effect it should have as far as phase shift is conce=
rned.

I have tried every combination of hall-phase relationships, inverted the ha=
ll signals and tried every combination, tried all the permutations of rotat=
ion sequence and hall relationship to motor phases. The configuration liste=
d above is the only one that works.

Any ideas anyone? =A0Any suggestions for further info sources? Am I an idio=
t?

Bill K.=A0
--=20
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