Control Techniques SM-Resolver - Page 10

10 SM-Resolver User Guide
www.controltechniques.com Issue Number: 4
3.5.2 Zero-position point
The resolver passes through its zero position when the following occur (see Figure 3-4):
SIN output
• The modulation is at minimum
• The carrier waveform changes from being in anti-phase with the excitation voltage
on the primary to being in phase with the excitation voltage on the primary
COS output
• The modulation is at maximum
• The carrier waveform is in phase with the excitation voltage on the primary
Figure 3-4 Modulation and carrier-phase conditions around the zero position of
the resolver
Excitation
(primary)
SIN
secondary
COS
secondary
Carrier with excitationin anti-phase
Zero
p
osition of resolver
Resolver
position
Carrier with excitationin phase
Carrier with excitationin phase
Carrier with excitationin phase