跳至主要内容

How to Choose and integrate a medical device with stepper motor

Recently almost every medical device I design requires a stepper motor. After working with these motors so frequently, I’d like to share what I’ve learned about medical device stepper motors, the different types of stepper motor configurations, and how to drive stepper motors properly.
How to Choose and integrate a medical device with stepper motor
Stepper Motor Drive Configurations
Stepper motors typically come in two motor winding configurations. Before selecting which configuration is appropriate for your application, you should understand the basic difference between the two. This choice will be important when selecting how to drive the motor.
Pro Tip: You can use a unipolar motor as a bipolar motor if you ignore the center tap. This can come in handy if a particular design of motor is only available in a unipolar configuration.
How to Choose and integrate a medical device with stepper motor
Stepper Motor Drive Signals
Typically three types of drive signals are used to control the motion of a stepper motor. Each drive type increases in complexity, but adds additional features and options.
How to Choose and integrate a medical device with stepper motor
A wave drive only energizes one phase at a time. Wave drives are simple to implement with basic hardware, but are rarely used. Because only one coil is energized at a time, torque is significantly reduced.
Stepper Motor Drive Circuits
The most common methods for driving a stepper motor include a simple constant voltage or L/R (L refers to electrical inductance and R stands for electrical resistance) driver, a chopper drive, or a sine wave/micro-stepper driver.
Stepper Motor Integrated Drivers
Once a stepper motor hybrid has been selected to suit its mechanical requirements, the next thing is to get that motor turning. It is easier than ever to make a motor operational by selecting an off the shelf stepper motor driver IC or development board. Many of these boards provide features such as current feedback, built in acceleration profiles, and even onboard path planning for more complicated motion control.

评论

发表评论

此博客中的热门博文

How to Choose the Right Pancake Stepper Motors for Your Needs

A step motor is a type of electric motor that uses a series of electrical pulses to move the rotor. The rotating rotor causes a linear actuator, which produces motion in one direction. The pancake stepper motor is a type of step motor that has the capability to rotate continuously in both directions without any need for periodic rotary encoder. It is also known as the "pancake" stepper because it resembles a pancake, with its flat shape and circular cross-section. This article discusses how this type of step motors work and their applications in industrial machinery such as 3D printers, CNC machines, and robotics. What Makes the Pancake Stepping Motor Different From Others? The pancake stepping motor is a type of electric generator that uses an electromagnet to produce electricity. It is also known as the pancake motor because it looks like a pancake when it is folded in half. It has been around since the 1970s, but it saw a surge in popularity after the Fuk
发表评论
阅读全文

What’s the difference between servo and closed loop stepper motors?

Servo and  closed loop stepper motor  have similar construction and share the same fundamental operating principle. Both motor types incorporate a rotor with permanent magnets and a stator with coiled windings … and both are operated by energizing or applying a dc voltage to the stator windings. That then causes the rotor to move. However, this is where the similarities between servo and stepper motors end. Drive methods for stepper motors Stepper motors have 50 to 100 poles and are two-phase devices. In contrast, servo motors have between four and 12 poles and are three-phase devices. What is more,  stepper motor driver  generate sine waves with a frequency that changes with speed … but with an amplitude that is constant. Servo drives, on the other hand, produce sine waves with variable frequency and amplitude — allowing them to control both speed and torque. Control methods for stepper motors Traditional stepper motors move when they receive a command to advance a cer
发表评论
阅读全文

What drivers Can i use on NEMA 17 motor or NEMA 24?

Description Nema 17 motor  is not standard for electrical characteristics of the stepper motor. It is just faceplate and mounting holes standard to make it easier to interchange motors. Most likely you have to check from the specification that what is rated current for that motor and is it unipolar or bipolar one. Choose driver based on that. Note: Drive can always be more powerful than the motor, but you have to limit your current from the drive side. It’s also possible to use chopper drives with the less current rating, but then your motor runs underpowered. But one can definitely make assumptions on the motor size that NEMA 17 could use 1A – 2A current and  NEMA 23 motor  could use around 2A – 5A current. How to run a stepper motor without a microcontroller? It’s totally possible since the drive doesn’t care where it gets it’s stepping impulses. You only need some kind of source for pulses and direction. The simplest option would be to use a NE555 timer chip.
发表评论
阅读全文