Resolvers with four output leads are general sine/cosine computational devices. Resolvers with four-lead rotors can rotate and coordinates, with the shaft position giving the desired rotation angle. Shaft angle is the polar angle, and excitation voltage is the magnitude. Resolvers can perform very accurate analog conversion from polar to rectangular coordinates. This device may also appear in non-brushless type, i.e., only consisting in two lamination stacks, rotor and stator.
WHAT IS SYNCHRO RESOLVER FULL
Upon one full revolution, the feedback signals repeat their waveforms.
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The relative magnitudes of the two-phase voltages are measured and used to determine the angle of the rotor relative to the stator. The two two-phase windings, fixed at right (90°) angles to each other on the stator, produce a sine and cosine feedback current. This current then flows through the other winding on the rotor, in turn inducing current in its secondary windings, the two-phase windings back on the stator. As these windings are arranged on the axis of the resolver, the same current is induced no matter what its position. The primary winding of the transformer, fixed to the stator, is excited by a sinusoidal electric current, which by electromagnetic induction induces current in the rotor. The rotor houses a coil, which is the secondary winding of the turning transformer, and a separate primary winding in a lamination, exciting the two two-phase windings on the stator. They are configured at 90 degrees from each other. The two other windings are on the bottom, wound on a lamination.
![what is synchro resolver what is synchro resolver](https://img.yumpu.com/38106180/1/500x640/ac-synchro-resolver-phase-definitions-from-mb-electronique.jpg)
This transformer induces current in the rotor without wires or brushes to provide a direct electrical connection. The exciter winding is located on the top it is a coil of a turning (rotary) transformer. The stator portion of the resolver houses three windings: an exciter winding and two two-phase windings (usually labeled "x" and "y") (case of a brushless resolver). On the inside, the configuration of the wire windings makes it different. On the outside, this type of resolver may look like a small electrical motor having a stator and rotor.
![what is synchro resolver what is synchro resolver](https://www.ddc-web.com/resources/assets/images/_Products/sb-3xxxxtx.jpg)
The most common type of resolver is the brushless transmitter resolver (other types are described at the end).