Hardware Peripheral Input/Output

stepper motor power drivers

A "stepper motor driver" is a board with some big transistors that turns the wimpy "step" pulses from a parallel port (or a microcontroller) into the high-voltage, high-power, sequence of coil energy sources for the wires of a stepper motor.

• NEW! Roman Black's Linistep 1. stepper controller kit Proceeds support PICList.com. Drives unipolar (5-wire or 6-wire) stepper motors.
• QuickStep drives unipolar stepper motors.
• Design of a High Current Bipolar Stepper Motor Driver drives bipolar (4-wire) stepper motors.
• AVR-Based Microstepping Bipolar Chopper Stepper Motor Driver (STMD) http://avrstmd.com/ , as the name suggests, drives bipolar stepper motors.

Stepper Motors

Also:

• Wiring for information on connecting stepper motors to drivers and finding which wire is which.
• Touque: The torque required to move a load is dynamic or detent torque. Don't be mislead by a rating of holding torque. Look for the torque curve.
  • Units Conversion
  • Measuring
• Floppy Motor Steppers
• Decoding Quadrature Encoders with a PIC
• Ubicom SX stepper motor controls
• PIC Microcontroller stepper motor controls
• Using Stepper Motors as Encoders
• Comming soon: QuickStep James Newton replies: see quickstepper.com for more.+

  +

A stepper motor is a kind of electric motor with an internal rotor containing permanent magnets and a set of electro-magnets around that which are switched electronically. Stepper motors "cog" to a limited number of positions, but with a microstepping controller, stepper motors can rotate more smoothly.

The primary advantages of stepper motors are that since they will move only as the controller changes the coil that is energized, the position of the motor can be known without any external feedback. Although it is possible for the motor to be turned out of phase with the coil exitation, which is know as skipping or missing steps, in most cases the reduced cost of the system is justified. Stepper motors are "brushless" unlike most other motors and so generate less EMI. Disadvantages include lower power effeciency, higher cost per unit, and the need for a more complex drive circuit aka controller.

The stepper motor controller typically accepts two inputs from an external source: Step and Direction. The Direction signal set the direction of rotation and each pulse on the Step signal causes the controller to move the motor one step in that direction. The controller translates these signals into different patterns of current flow in the coils, which result in the movent of the motor.

Type 23, NEMA 23 or any other like that refers to the mounting arrangement only (mounting hole pattern and size, diameter of shaft)

See also:

• http://www.codeproject.com/vbscript/Stepper_Motor_Control.asp Stepper Motor Control through Parallel Port from a Visual Basic script in MS Excel
• http://linuxgazette.net/122/sreejith.html Liniux stepper motor tutorial
• /techref/member/FL-gmail-A53/index.htm 2 stepper motor driver+
• spamaaron.groups~NOSPAM~ at spamgmail.com refers to

  http://www.bright.net/~agarb/STMD/STMD.html For those that are interested, I've been working on an open-source bipolar, microstepping chopper stepper drive. Schmatics are available and it is my intention to also make the source code availabe once I get it cleaned up.

• http://www.cs.uiowa.edu/~jones/step Nice tutorial on steppers
• http://www.doc.ic.ac.uk/~ih/doc/stepper/ Nice tutorial on steppers
• http://www.beowulf.demon.co.uk/serial-stepper.html
• http://www.allegromicro.com Has some nice stepper motor controllers with logic, protection, drivers, etc... all built in.
• http://www.njr.co.jp/e05/ee.htm excellent app notes with full theory but also practical applications.
• http://web.archive.org/web/19990218185922/http://www.sig-positec.co.uk/bmotors.htm info on different types, etc... pictures missing.
• http://www.galilmc.com/support/motorsizer/index.html You put in system type, load mass, etc... and it tells you want motor and drivers to use. Does require registration.

Roman Black says:

http://romanblack.com/stepper.htm   "I have built a test rig to measure both holding torque and shaft angle with high accuracy. This will let me measure (tune) motors for microstepping, to get exact torque and angle for every microstep.

If anyone is interested I have done the measurement on a 5.1v 1A/phase bipolar 23-frame motor, it was WAY off the mathematic values that many microstepping drivers run at. Now I can tune my new CNC driver for perfect performance. Note that this motor is very similar to many common "surplus" steppers that we all use for projects"

Questions:

See:

• /techref/piclist/cump/hardware.htm CUMP hardware+

Comments:

  .