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.
- 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.
|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|