please click here - General Dynamics Global Imaging Technologies
please click here - General Dynamics Global Imaging Technologies
please click here - General Dynamics Global Imaging Technologies
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Commutating Brushless DC Motors<br />
(800) 777-3393<br />
= Angle between the plane of the Hall<br />
element and the rotor permanent<br />
magnet field vector(degrees)<br />
The current in A winding is:<br />
I A =V HK 2K 3<br />
= K2K3 KHICB Cos <br />
= K2K3 KHK1B VC Cos <br />
Similarly, the current in B winding is:<br />
IB= K2K3KHICBVC Sin <br />
The torque output of each phase is:<br />
TA = IAKT Cos <br />
TB = IBKT Sin <br />
Substituting for IA and IB TA = VCK1K2K3 KHKTB Cos2 <br />
TB = VCK1K2K3 KHKTB Sin2 <br />
Direction Control Input<br />
Brushless DC Motors<br />
Let KC = K1K2K3 KHKTB Then the motor’s output torque is:<br />
T = TA + TB = VCKC (Cos2 + Sin2 )<br />
T = VCKC T<strong>here</strong>fore, the output torque is directly pro-<br />
www.axsys.com<br />
><br />
+V S<br />
S1<br />
+V S<br />
S2<br />
Pancake Resolvers >> Brush Type Motors >><br />
Power<br />
Mosfet<br />
Drive<br />
CKT<br />
Figure-11. Functional drive circuit for bidirectional<br />
control of a two phase brushless DC motor.<br />
Figure-12. Functional drive circuit for bidirectional control of a three phase brushless DC motor.<br />
Q1<br />
Q3<br />
Q2<br />
Q4<br />
+V<br />
-V<br />
+V<br />
-V<br />
OB<br />
OA
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