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Understanding Resolvers and Resolver-to-Digital Conversion

From Admotec Inc.
 

 
A resolver is a position sensor or transducer which measures the instantaneous angular position of the rotating shaft to which it is attached. Resolvers and their close cousins, synchros, have been in use since before World War II in military applications such as measuring and controlling the angle of gun turrets on tanks and warships. Resolvers are typically built like small motors with a rotor (attached to the shaft whose position is to be measured), and a stator (stationary part) which produces the output signals. The word resolver is a generic term for such devices derived from the fact that at their most basic level they operate by resolving the mechanical angle of their rotor into its orthogonal or Cartesian (X and Y) components. From a geometric perspective, the relationship between the rotor angle () and its X and Y components is that of a right triangle:
Products & Services
Incremental rotary encoders are multi-turn sensors that use optical, mechanical, or magnetic index-counting for angular measurement. They contain no absolute reference, but instead count relative to the turn-on position. Search by Specification | Learn more about Incremental Rotary Encoders
Rotary position sensors include potentiometers, resolvers and a variety of magnetic and capacitive technologies. Sensors are designed for angular displacement less than one turn or for multiturn displacement. Search by Specification | Learn more about Rotary Position Sensors
Product Announcements
SSD Drives, a Division of Parker Hannifin Corp. - HW Spindle Motors
The HW servomotors are water-cooled Brushless Synchronous motors delivered as individual components (rotor, stator and resolver) to make a complete spindle unit. These motors are driven by Digivex DPD... (read more)
Parker Hannifin/Electromechanical Automation - Higher-Performance Servo Motors - From Parker
Parker's MPP motors feature segmented lamination technology, which can yield up to 40% higher torque per unit size than conventionally wound servo motors. "Potted" stators improve heat transfer for... (read more)
Topics of Interest
Today, frameless brushless (pancake) resolvers are commonly used on AC and brushless DC servomotors to provide commutation, position, and velocity information to the servo controller. These angular... (Read More)
Specialty Motors General Principles of Operation-Stepper A step or stepper motor is one in which electrical pulses are converted into mechanical movements. A standard DC motor, for example, rotates... (Read More)
Overview The precise control of speed, position or acceleration requires appropriate measuring systems to be applied to the controlled variable. Although considerable progress has been made in the... (Read More)
Permanent Magnet (PM) Brushless Motors  The permanent magnet brushless dc motor has been in existence for about three decades and is finally being widely used for many applications1,5,6. Its... (Read More)
The material in this subsection is framed in terms of three-phase (q=3) machine theory, but it is actually generalizable to an arbitrary number of phases. Suppose a machine whose three-phase... (Read More)
See more product announcements for Incremental Rotary Encoders
Sub-Miniature Commutating Encoder, Model R22i

Sub-Miniature Commutating Encoder, Model R22i
Renco Encoders, Inc.


MSR 50 MK

MSR 50 MK
Automation and Metrology, Inc.


MS 30 Exposed Linear Encoder

MS 30 Exposed Linear Encoder
Automation and Metrology, Inc.


11 See more product announcements for Incremental Rotary Encoders