Saturday, April 28, 2018

The benefits of Closed-Loop Stepper Motor

The closed-loop control of stepper motor can determine the phase transition with the rotor position by using position feedback and (or) speed feedback, which can greatly improve the performance of stepper motor.

The benefits of Closed-Loop Stepper Motor

In the closed-loop control system (including closed loop stepper driver) of the stepper motor, or the tracking and feedback with specific accuracy, we should expand the range of working speed, improve the tracking and positioning accuracy at a given speed, or get the speed limit and accuracy index limit.

A closed-loop step motor system combines the advantages of servo motor and stepper motor technologies. Functionally, a closed-loop stepper motor system will run much more smoothly and with less resistance than a standard stepper motor setup. Since a closed-loop system provides feedback and control as well as short transient and free oscillation times, the closed-loop system will not lose or gain steps.

A closed-loop stepper motor system, such as the 34HS38-4204D-E1000, may be the best option when the application requires improved energy efficiency and smoothness of operation, especially at high loads. In addition, a closed-loop system has the advantage over servo motor systems of higher torque at low RPMs. Additional benefits include short transient times, less packaging, accurate/correct positioning using feedback from encoders integrated into the motor(s) to the controller, and comparatively low prices.

Tuesday, April 24, 2018

Some difference between DC motor and Stepper motor

DC (high speed high torque bldc motor) Motors are two wire (power & ground), continuous rotation motors.
-The speed of DC motors is controlled using pulse width modulation (PWM), a technique of rapidly pulsing the power on and off. The percentage of time spent cycling the on/off ratio determines the speed of the motor, e.g. if the power is cycled at 50% (half on, half off), then the motor will spin at half the speed of 100% (fully on). Each pulse is so rapid that the motor appears to be continuously spinning with no stuttering.

Some difference between DC motor and Stepper motor

Servo Motor:
-Servo motors are generally an assembly of four things: a DC motor, a gearing set, a control circuit and a position-sensor (usually a potentiometer).
-The position of servo motors can be controlled more precisely than those of standard DC motors, and they usually have three wires (power, ground &). Power to servo motors is constantly applied, with the servo control circuit regulating the draw to drive the motor.
-PWM is used for the control signal of servo motors. However, unlike DC motors it’s the duration of the positive pulse that determines the position, rather than speed, of the servo shaft.

Stepper Motor:
-Stepper motors for sale utilizes multiple toothed electromagnets arranged around a central gear to define position.
-Stepper motors require an external control circuit or micro controller (e.g. a Raspberry Pi or Arduino) to individually energize each electromagnet and make the motor shaft turn.

Monday, April 23, 2018

What's wrong with ordinary electric motors?

An ordinary electric motor is based on a simple bit of magnet science we all learn at school: unlike poles attract, like poles repel. Here's how a basic motor works. You take a ring-shaped magnet, put a coil of wire inside it, and feed electricity through the wire. The wire becomes a temporary magnet powered by electricity—an electromagnet, in other words—and the magnetic field it creates repels the field from the permanent magnet that surrounds it.

A large electric motor from an electric lawn mower
Photo: The powerful electric motor from an old lawn mower. The slots at the front are part of the commutator, which is an ingenious device that reverses the electric current and keeps the rotor (the rotating, central part of the motor) spinning in the same direction.

A large electric motor from an electric lawn mower

We can also make motors that work using AC (alternating current) instead of DC. Although they're engineered in a radically different way, they're still based on "like poles repel, unlike poles attract": the electricity that powers the motor creates magnetic attraction and repulsion, and a force that makes the motor spin. You'll find more about AC motors—which are also called induction motors—in our article on AC induction motors.

Whether they're powered by DC or AC, ordinary motors are the hidden electric muscles that power modern life: you'll find them in all kinds of gadgets and gizmos in the world around you, from food blenders and refrigerators to vacuum cleaners and electric trains. But in all these machines, the rotors of their motors spin continuously. When you vacuum a carpet or commute to work by subway, the motors that are working for you turn around an arbitrary number of times: there's no precise control over how many times they rotate and what angle they spin through—and it really doesn't matter.

Basic Stepper Motor Operation principles

What are the commonly used motors for CNC lathes?

1.Stepper motor Stepper motor is one of the more commonly used motors in CNC lathes. Its principle is to add electromagnetics in the column ...