【正文】 motor windings of each phase in order to control the stepper motor rotation.38 Induction Stepping Motor381 features: Induction, pared with the traditional reactive, structural reinforced with a permanent magnet rotor, in order to provide the working point of soft magnetic materials, and the stator excitation magnetic field changes only need to provide to provide the operating point of the consumption of magnetic materials energy, so the motor efficiency, current, low heat. Due to the presence of permanent magnets, the motor has a strong EMF, the damping effect of its own good, it is relatively stable during operation, low noise, low frequency vibration. Induction can be seen as somewhat lowspeed synchronous motor. A fourphase motor can be used for fourphase operation, but also can be used for twophase operation. (Must be bipolar voltage drive), while the motor is not so reactive. For example: four phase, eightphase operation (AABBBCCCDDDAA) can use twophase eightshot run. Not difficult to find the conditions for C =, D =. a twophase motor39。s internal winding consistent with the fourphase motors, small power motors are generally directly connected to the second phase, the power of larger motor, in order to facilitate the use and flexible to change the dynamic characteristics of the motor, its external connections often lead to eight (fourphase), so that when used either as a fourphase motors used, can be used for twophase motor winding in series or parallel.382 classification：Induction motors can be divided in phases: twophase motor, three phase motor, fourphase motor, fivephase motor. The frame size (motor diameter) can be divided into: 42BYG (BYG the Induction Stepping motor code), 57BYG, 86BYG, 110BYG, (international standard), and like 70BYG, 90BYG, 130BYG and so are the national standards.383 the stepper motor phase number of static indicators of terms: very differently on the N, S the number of magnetic field excitation coil. Common m said. Beat number: plete the necessary cyclical changes in a magnetic field pulses or conducting state with n said, or that turned a pitch angle of the motor pulses needed to fourphase motor, for example, a fourphase fourshot operation mode that AB BCCDDAAB, shot eight fourphase operation mode that AABBBCCCDDDAA. Step angle: corresponds to a pulse signal, the angular displacement of the rotor turned with θ said. θ = 360 degrees (the rotor teeth number of J * run shot), the conventional two, fourphase, the rotor teeth 50 tooth motor as an example. Four step runtime step angle θ = 360 176。 / (50 * 4) = degrees (monly called the whole step), eightshot running step angle θ = 360 176。 / (50 * 8) = degrees (monly known as half step.) Location torque: the motor is not energized in the state, its locked rotor torque (as well as by the magnetic field profile of harmonics caused by mechanical error) static torque: the motor under the rated static electricity, the motor without rotation, the motor shaft locking torque. The motor torque is a measure of volume (geometry) standards, and drive voltage and drive power, etc. has nothing to do. Although the static torque is proportional to the electromagnetic magnetizing ampere turns, and fixed air gap between the rotor teeth on, but overuse of reduced air gap, increase the excitation ampereturns to increase the static torque is not desirable, this will cause the motor heating and mechanical noise.39 Characteristics of the stepper motor1. The general accuracy of the stepper motor step angle of 35%, and not cumulative.2. Appearance of the stepper motor to allow the maximum temperature. Stepper motor causes the motor temperature is too high the first magnetic demagnetization, resulting in loss of torque down even further, so the motor surface temperature should be the maximum allowed depending on the motor demagnetization of magnetic material points。 Generally speaking, the magnetic demagnetization points are above 130 degrees Celsius, and some even as high as 200 degrees Celsius, so the stepper motor surface temperature of 8090 degrees Celsius is normal.3. Stepper motor torque will decrease with the increase of speed. When the stepper motor rotates, the motor winding inductance of each phase will form a reverse electromotive force。 the higher the frequency the greater the back emf. In its role, the motor with frequency (or speed) increases with the phase current decreases, resulting in decreased torque.4. Lowspeed stepper motor can operate normally, but if not higher than a certain speed to start, acpanied by howling. Stepper motor has technical parameters: noload starting frequency, ie the stepper motor with no load to start the normal pulse frequency, pulse frequency is higher than the value if the motor does not start, you may lose steps or stall occurs. In the case of a load, start frequency should be lower. If you want the motor to achieve highspeed rotation, the pulse frequency should speed up the process, which started lower frequency, and then rise by a certain acceleration of the desired frequency (motor speed from low rise to highspeed). Stepper motor with its significant features, in the era of digital manufacturing play an important purpose. Along with the different development of digital technology and the stepper motor itself, improvements in technology, the stepper motor will be applied in more fields.計算機控制技術(shù)1. 計算機的結(jié)構(gòu)與功能這一節(jié)介紹計算機的內(nèi)部體系結(jié)構(gòu)，描述了指令如何存儲和譯碼，并解釋了指令執(zhí)行周期怎樣分解成不同的部分。圖 31A1 計算機的基本元件從最基本的水平來講，計算機簡單執(zhí)行存儲在存儲器中的二進制編碼指令。這些指令按照二進制編碼數(shù)據(jù)來產(chǎn)生二進制編碼結(jié)果。對于通用可編程計算機，四個必要部件是存儲器、中央處理單元（CPU，或簡稱處理器），外部處理器總線，輸入/輸出系統(tǒng)。 存儲器儲存指令和數(shù)據(jù)。 CPU讀取和解釋指令，讀每條指令所需的數(shù)據(jù)，執(zhí)行指令所需的操作，將結(jié)果存回存儲器。CPU所需的操作之一是從外部設(shè)備讀取或?qū)懭霐?shù)據(jù)。這利用輸入/輸出系統(tǒng)來實現(xiàn)。 外部處理器總線是一套能在其他計算機部件之間傳送數(shù)據(jù)、地址和控制信息的電導(dǎo)線。 11 存儲器計算機的存儲器是由一套連續(xù)編號的單元所組成。每個存儲單元是一個能存二進制信息的寄存器。單元的編號稱為地址。初始地址為0。制造商定義處理器的一個字長為單元的整數(shù)長。在每個字中，各位表示數(shù)據(jù)或指令。對于英特爾8086/87和摩托羅拉MC68000微處理器來說，一個字是