vb.net barcode reader source code WAVE STEP SEQUENCE in Software

Create QR Code ISO/IEC18004 in Software WAVE STEP SEQUENCE

21.1.1 WAVE STEP SEQUENCE
Reading QR Code In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
QR Code 2d Barcode Generation In None
Using Barcode encoder for Software Control to generate, create QR Code JIS X 0510 image in Software applications.
In operation, the common wires of a unipolar stepper are attached to the positive (sometimes the negative) side of the power supply. Each winding is then energized in turn by grounding it to the power supply for a short time. The motor shaft turns a fraction of a revolution each time a winding is energized. For the shaft to turn properly, the windings must be energized in sequence. For example, energize wires 1, 2, 3, and 4 in sequence and the motor turns clockwise. Reverse the sequence, and the motor turns the other way.
QR Code Recognizer In None
Using Barcode scanner for Software Control to read, scan read, scan image in Software applications.
QR-Code Creator In C#.NET
Using Barcode printer for VS .NET Control to generate, create QR Code image in VS .NET applications.
21.1.2 FOUR-STEP SEQUENCE
Printing QR Code JIS X 0510 In VS .NET
Using Barcode creator for ASP.NET Control to generate, create QR-Code image in ASP.NET applications.
QR Code Printer In VS .NET
Using Barcode encoder for VS .NET Control to generate, create Denso QR Bar Code image in Visual Studio .NET applications.
The wave step sequence is the basic actuation technique of unipolar stepper motors. Another, and far better, approach actuates two windings at once in an on-on/off-off four-
QR Code Encoder In VB.NET
Using Barcode generator for VS .NET Control to generate, create QR Code ISO/IEC18004 image in Visual Studio .NET applications.
EAN-13 Encoder In None
Using Barcode encoder for Software Control to generate, create GTIN - 13 image in Software applications.
FIGURE 21-1 A typical unipolar stepper motor.
Creating Bar Code In None
Using Barcode generator for Software Control to generate, create barcode image in Software applications.
Print UCC.EAN - 128 In None
Using Barcode generator for Software Control to generate, create GS1-128 image in Software applications.
21.1 INSIDE A STEPPER MOTOR
Code 128A Maker In None
Using Barcode drawer for Software Control to generate, create Code 128B image in Software applications.
Making Bar Code In None
Using Barcode encoder for Software Control to generate, create bar code image in Software applications.
Rotor (Shaft)
DUN - 14 Drawer In None
Using Barcode generator for Software Control to generate, create ITF-14 image in Software applications.
Read GS1 128 In VB.NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
Coil
Create Bar Code In Objective-C
Using Barcode drawer for iPad Control to generate, create bar code image in iPad applications.
GS1 - 12 Creator In .NET
Using Barcode encoder for .NET Control to generate, create UPC-A Supplement 5 image in Visual Studio .NET applications.
Stator Cup
Matrix 2D Barcode Encoder In Visual Basic .NET
Using Barcode creator for VS .NET Control to generate, create Matrix Barcode image in .NET applications.
Create Bar Code In Visual Studio .NET
Using Barcode drawer for .NET Control to generate, create barcode image in Visual Studio .NET applications.
Stator Cup 2
UPC - 13 Decoder In None
Using Barcode scanner for Software Control to read, scan read, scan image in Software applications.
Code 3/9 Printer In None
Using Barcode encoder for Microsoft Excel Control to generate, create Code 3 of 9 image in Office Excel applications.
Coil
FIGURE 21-2 Inside a unipolar stepper motor. Note the two sets of coils and stators. The unipolar stepper is really two motors sandwiched together.
step sequence, as shown in Fig. 21-4. This enhanced actuation sequence increases the driving power of the motor and provides greater shaft rotation precision. There are other varieties of stepper motors, and they are actuated in different ways. One you may encounter is bipolar. It has four wires and is pulsed by reversing the polarity of the power supply for each of the four steps. The actuation technique for these motors will be discussed later in this chapter.
Common Phase 2 Common
Phase 3 Phase 4
FIGURE 21-3 The wiring diagram of the unipolar stepper. The common connections can be separate or combined.
WORKING WITH STEPPER MOTORS
STEP 1 Clockwise 2
PHASE 1
PHASE 2
PHASE 3
PHASE 4
Counterclockwise 3 4 OFF ON
FIGURE 21-4 The enhanced on-on/off-off four-step sequence of a unipolar stepper motor.
21.2 Design Considerations of Stepper Motors
Stepping motors differ in their design characteristics compared with continuous DC motors. The following section discusses the most important design specifications for stepper motors.
21.2.1 STEPPER PHASING
A unipolar stepper requires that a sequence of four pulses be applied to its various windings for it to rotate properly. By their nature, all stepper motors are at least two-phase. Many are four-phase; some are six-phase. Usually, but not always, the more phases in a motor, the more accurate it is.
21.2.2 STEP ANGLE
Stepper motors vary in the amount of rotation of the shaft each time a winding is energized. The amount of rotation is called the step angle and can vary from as small as 0.9 (1.8 is more common) to 90 . The step angle determines the number of steps per revolution. A stepper with a 1.8 step angle, for example, must be pulsed 200 times for the shaft to turn one complete revolution. A stepper with a 7.5 step angle must be pulsed 48 times for one revolution, and so on.
21.2.3 PULSE RATE
Obviously, the smaller the step angle is, the more accurate the motor. But the number of pulses stepper motors can accept per second has an upper limit. Heavy-duty steppers usually have a maximum pulse rate (or step rate) of 200 or 300 steps per second, so they have an effective top speed of 1 to 3 r/s (60 to 180 r/min). Some smaller steppers can accept a thousand or more pulses per second, but they don t usually provide very much torque and aren t suitable as driving or steering motors.
21.2 DESIGN CONSIDERATIONS OF STEPPER MOTORS
Note that stepper motors can t be motivated to run at their top speeds immediately from a dead stop. Applying too many pulses right off the bat simply causes the motor to freeze up. To achieve top speeds, you must gradually accelerate the motor. The acceleration can be quite swift in human terms. The speed can be one-third for the first few milliseconds, two-thirds for the next few milliseconds, then full blast after that.
21.2.4 RUNNING TORQUE
Steppers can t deliver as much running torque as standard DC motors of the same size and weight. A typical 12-V, medium-sized stepper motor may have a running torque of only 25 oz-in. The same 12-V, medium-sized standard DC motor may have a running torque that is three or four times more. However, steppers are at their best when they are turning slowly. With the typical stepper, the slower the motor revolves, the higher the torque. The reverse is usually true of continuous DC motors. Fig. 21-5 shows a graph of the running torque of a medium-duty, unipolar 12-V stepper. This unit has a top running speed of 550 pulses per second. Since the motor has a step angle of 1.8 , that results in a top speed of 2.75 r/s (165 r/min).
Copyright © OnBarcode.com . All rights reserved.