In this two-part series, we go over the basic definition of types of repeatability and their application in linear motion and actuation applications. Part 2 covers bidirectional repeatability. (Click here for Part 1.) Information courtesy of IntelLiDrives Corp. As noted in Part 1, repeatability can be defined as the variation in results for a series […]
FAQs + basics
How does stiffness affect piezo output force and displacement?
Piezo actuators operate on the inverse piezoelectric effect: when voltage is applied, the actuator contracts or expands. But when the actuator is blocked from moving (by a load applied in the direction of travel), it generates a force. This relationship between displacement and force in piezo materials is an inverse relationship. In other words, the […]
Precision motion control FAQ: What is repeatability? (Part 1)
In this two-part series, we go over the basic definition of types of repeatability and their application in linear motion and actuation applications. Part 1 covers unidirectional repeatability. Information courtesy of IntelLiDrives Corp. Effectively automating any industrial operation, test procedure, or prototype process involving motion requires determining the movement precision needed to yield acceptable results. […]
What are the benefits of an active front end (AFE) drive?
A variable frequency drive, or VFD, delivers power from the source — typically the utility — to a motor in three basic steps: A rectifier converts the AC power to DC A DC bus receives, smooths, and stores the power An inverter converts the DC power back into AC with the necessary frequency and voltage […]
What are wound field motors and where are they applied?
Brushed DC motors are generally available in two types, depending on the construction of the stator: permanent magnet or wound field. Both motor types use current and windings to produce a magnetic field in the rotor, but they differ in how the stator magnetic field is produced: via permanent magnets inside the stator or with […]
How to program a motion controller?
Programming a motion controller is the act of giving a controller the instructions to complete some motion task. The task could be as simple as controlling a single-axis actuator to move a short distance and back again. Or it could be controlling and coordinating the movement of a complex, interconnected multi-axis motion system such as […]
How do rotary voice coil actuators work?
Most linear motion devices have a rotary equivalent, and voice coil actuators are no exception. While the versions depicted in most product images and videos are linear, rotary voice coil actuators fill a need for smooth, arc-shaped motion and torque production with fast response times. But unlike the design relationship between rotary and linear motors, […]
What is the Department of Energy’s Integral Horsepower Rule?
The U.S. Department of Energy (DOE) has been regulating energy efficiency for electric motors since 1997, when the Energy Policy Act went into effect, requiring most 1 to 200 hp general-purpose motors to meet NEMA Energy Efficiency standards. Since then, the DOE energy efficiency regulations have evolved, with the Energy Independence and Security Act (EISA) […]
What’s the difference between an EC motor and a BLDC motor?
Deciphering motor terminology can be frustrating, especially when comparing the operation and performance of various motor types. For example, some motors are characterized by their speed (synchronous or asynchronous) while others are characterized by their commutation method (brushed or brushless). And then there’s the issue of whether the motor is operated with AC or DC […]
What is a Halbach array and how is it used in electric motors?
A Halbach array is arrangement of permanent magnets that creates a stronger field on one side while reducing the field on the other side to near zero. This is accomplished by orienting the magnets so that their poles are out of phase, typically by 90 degrees. This orientation essentially re-routes the magnetic field below the […]