VERNIER RESOLVER 



1495 



10 



Q 



z 

 o 

 o 



LU 



m 



z 



-10 



o 



3° 20' 6° 40' 



SHAFT ANGLE, ©rn 



10°0' 



13°20 



Fig. 6 — Error of a 27th order vernier resolver over one vernier interval. 



It may be pointed out that the housing of the tested unit was of 

 aluminum. A unit with a non-magnetic steel housing should be of lower 

 temperature drift, because stator stack and housing would then have the 

 same temperature coefficient of expansion. 



3. .3 Transformation Ratio, Input and Output Impedances 



At maximum coupling the induced output voltage is 0.123 times the 

 exciting voltage and is leading in phase by 6°. 



The impedance of the input winding with the output windings open 

 is 117 + J 781 ohms. 



The impedance of the output windings with the primary winding 

 shorted is 235 + j 920 ohms. 



The effect of the rotor position on this impedance is hardly noticeable. 



3.4 Output Signal Distortions 



The harmonic content of the output signal at maximum coupling is: 



fundamental 1.7 volts 

 2nd harmonic 0.2 mv 

 3rd harmonic 13.5 mv 

 5th harmonic 5.4 mv 



The harmonic content of the output signal at minimum coupling (null 

 voltage) is: 



fundamental 1.6 mv 

 2nd harmonic 0.05 mv 

 3rd harmonic 2.0 mv 



