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Resolver Feedback


Two fixed stator windings are arranged shifted by 90°, surrounding the rotor (rotor winding). The rotor winding is supplied with a sinusoidal AC voltage.


The tensions induced in S1 and S2 (amplitudes) depend on the rotor angle and correspond to the sine and cosine of the rotor angle.


The rotor angle alpha is calculated by the amplitudes a1 and a2 with α=arctan (a1/a2)


Beside the described 2-poles Resolver there are multipole designs. A 4-poles Resolver supplies a phase shift of 2·360° during one rotor revolution.


Resolvers are used in many applications such as textile machines, mining industry machines and servo motors due to their robust and economical design. Resolvers work nearly wear-free.

Resolver Specification for AKD

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Resolver Specification for S300/S700

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Resolver Specification for S400/S600

  • Excitation voltage is 4,9 Vrms (û = 7V)
  • Frequency is 8 KHz
  • Max. excitation current is 35 mA
  • Max. phase shift is +/- 10° at 8KHz
  • Transformation ratio is 0.5

Transformation ratio is 0.5   Enclosed are data of 3 different resolver types that fit the requirements.

  V23401-H1005-B101 JSSBH-15 JSSBH-21
Manufacturer Siemens Litton Litton
Status High Impedant Optimum Low Impedant
Input Voltage 4Vrms, 5Khz 7Vrms, 5Khz 7Vrms, 5Khz
Phase Shift 16° +/-4° 17° +/-3° 16° +/-4°
Impedance Zro (Ohm) 169 + J311 73 + J93 73 + J65
Impedance Zso (Ohm) 119 + J164 135 + J170 110 + J210
Impedance Zss (Ohm) 134 + J228 115 + J150 105 + J185
DC Res. Stator (Ohm) 55 77 55
DC Res. Rotor (Ohm) 24 40 23
Electrical Error +/- 10 min +/- 10 min +/- 10 min

Further Information