畢業(yè)設(shè)計(jì)外文翻譯--基于c51兼容微處理器單片機(jī)的pwm控制器設(shè)計(jì)-其他專業(yè)-在線瀏覽
2025-03-24 04:17本頁面
【正文】 wer with fixed voltage to modify the twoend voltage of load. This technology can be used for a variety of applications including motor control, temperature control and pressure control and so on. In the motor control system shown as Fig. 1, through adjusting the duty cycle of power switch, the speed of motor can be controlled. As shown in Fig. 2, under the control of PWM signal, the average of voltage that controls the speed of motor changes with Dutycycle ( D = t1/T in this Figure ), thus the motor speed can be increased when motor power turn on, decreased when power turn off. : The Relationship between Voltage of Armature and Architecture of PWM Module Therefore, the motor speed can be controlled with regularly adjusting the time of turnon and turnoff. There are three methods could achieve the adjustment of duty cycle: (1) Adjust frequency with fixed pulsewidth. (2) Adjust both frequency and pulsewidth. (3) Adjust pulsewidth with fixed frequency. Generally, there are four methods to generate the PWM signals as the following: (1) Generated by the device posed of separate logic ponents. This method is the original method which now has been discarded. (2) Generated by software. This method need CPU to 外文翻譯 2 continuously operate instructions to control I/O pins for generating PWM output signals, so that CPU can not do anything other. Therefore, the method also has been discarded gradually. (3) Generated by ASIC. The ASIC makes a decrease of CPU burden and steady work generally has several functions such as overcurrent protection, deadtime adjustment and so on. Then the method has been widely used in many kinds of occasion now. (4) Generated by PWM function module of MCU. Through embedding PWM function module in MCU and initializing the function, PWM pins of MCU can also automatically generate PWM out signals without CPU controlling only when need to change dutycycle. It is the method that will be implemented in this paper. In this paper, we propose a PWM module embedded in a 8051 microcontroller. The PWM module can support PWM pulse signals by initializing the control register and dutycycle register with three methods just mentioned above to adjust the duty cycle and several operation modes to add flexibility for user. The following section explains the architecture of the PWM module and the architectures of basic functional blocks. Section3 describes two operation modes. Experimental and simulatio
環(huán)評(píng)公示相關(guān)推薦
鄂ICP備17016276號(hào)-1