How PWM pulse width modulation works

The Pulse Width Modulator, PWM for short, and DC motor governor is the equipment for regulating the speed of a DC motor. Because the DC motor has the characteristics of low speed and large torque, it cannot be replaced by the AC motor, so the equipment for adjusting the speed of the DC motor is used. - DC governor, because of its special performance, it is often used in DC load circuit, lighting dimming or DC motor speed regulation, HW-1020 type governor, is the use of pulse width modulation (PWM) principle of the motor Speed ​​governors and PWM governors have been widely used in industrial DC motor speed control, industrial conveyor belt speed control, lighting lighting mediation, computer power dissipation, and DC fan.
Edit this section working principle HW-A-1020 type (DC12v24v voltage universal) governor, working principle: by changing the output square wave duty cycle so that the load on the average current power from 0-100% change, thus changing Load, light intensity/motor speed. The use of pulse width modulation (PWM) to achieve dimming / speed regulation, its advantages are the power of the power, can be fully utilized, and the efficiency of the circuit is high. For example: When the output is a 50% square wave, the output power of the pulse width modulation (PWM) circuit is also 50%, ie almost all the energy is transferred to the load. The use of common resistance buck speed regulation, the load to obtain the maximum power of 50% of the power supply, the power supply must provide more than 71% of the output power, of which 21% consumed in the resistance of the pressure drop and heat loss. Most of the energy is consumed in the resistor, the remaining energy is output, and the conversion efficiency is very low. In addition, the HW-A-1020 type speed control is almost non-existent due to its use of switching heat consumption, HW-A-1020 type speed is very large torque at low speed, because the governor with automatic tracking PWM, in addition to pulse width modulation The (PWM) mode allows the load to get almost full supply voltage during operation, which is advantageous to overcome the inherent coil resistance of the motor and allow the motor to generate a greater torque rate.
Edit this paragraph DC motor selection Under what circumstances should choose to use DC converter?
First, the following occasions need to use DC speed regulator:
1. Need a wide range of speed.
2. Need a faster dynamic response process.
3. Automatic smooth transition is required during acceleration and deceleration.
4. Large torque is required for low speed operation.
5. The need for better excavator characteristics will automatically limit the overload current to the set current.
The above five points are also characteristics of DC governor applications.
Second, DC governor application:
DC governor in CNC machine tools, paper printing, textile printing and dyeing, cable equipment, packaging machinery, electrical machinery, food processing machinery, rubber machinery, biological equipment, printed circuit board equipment, laboratory equipment, welding cutting, light industrial machinery , Logistics transportation equipment, rolling stock, medical equipment, communications equipment, radar equipment, satellite ground receiving systems and other industries are widely used.
Third, the DC governor works a brief introduction:
The DC speed regulator is a device that regulates the speed of the DC motor. The upper end is connected with the AC power supply, and the lower end is connected with the DC motor. The DC speed converter converts the AC power into two output DC power supplies, one input to the DC motor magnet (stator), all the way. It is input to the armature (rotor) of the DC motor. The DC governor regulates the DC motor speed by controlling the armature DC voltage. At the same time, the DC motor gives a feedback current to the governor. The governor judges the rotation speed of the DC motor according to the feedback current, and corrects the armature voltage output if necessary to adjust the motor speed again.
Fourth, the speed regulation scheme of the direct current electrical machinery generally has the following 3 kinds of ways: 1, changes the armature voltage; 2, changes the excitation winding voltage; 3, changes the armature circuit resistance. The most commonly used is the pressure regulator system, which is 1 (change armature voltage).
5. A modular DC motor governor, which integrates power supply, control, and drive circuits. It adopts a three-dimensional structure layout. The control circuit adopts micro-power components, and optocouplers realize current and voltage isolation and transformation. Constants, integral constants, and derivative constants are adjusted with PID adapters. The governor is small in size and light in weight, and can be used alone or directly on a DC motor to constitute an integrated DC speed regulating motor, which can have all the functions that the governor should have.
6. A modular DC motor governor, which integrates power supply, control, and drive circuits. It adopts a three-dimensional structure layout. The control circuit uses micro-power components, and optocouplers realize current and voltage isolation and transformation. Constants, integral constants, and differential constants are adjusted with the pid adapter. The governor is small in size and light in weight. It can be used alone or directly on a DC motor to form an integrated DC speed governor. It can have all the functions that the governor should have. Seven: The rapid development of modern industrial automation is also given. DC motor control and speed control provide a wide range of applications and updates: such as remote signal transmission, remote speed control, remote control and control of high-temperature environment, manual automatic integration.

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