dc motor speed control method of controller is divided into one kind is to regulate the armature voltage, one kind is adjusting excitation current, by dc motor controller of the enterprise below small make up to you about the speed of dc motor controller, a variety of situations. 1, the common miniature dc motor controller because of its magnetic field are fixed, not the permanent magnets, so I had to regulate the armature voltage. Regulate the armature voltage method: common one is the silicon controlled voltage regulating method, and pulse width modulation method (脉宽调制)。 PWM H belong to regulating speed. The H bridge can only achieve high power PWM control. The super power of the domestic control implemented depends on silicon controlled rectifier to regulating speed regulation of dc motor controller. 2, the weak magnetic speed regulating, weakened by appropriate excitation magnetic field method can speed. Second, the dc motor speed controller and ac motor controller is dc motor controller is the biggest advantage is the dc motor controller can achieve 'smooth and economic control'; Speed control of dc motor controller don't need other equipment, but by changing the input voltage/current, or excitation voltage/current to speed. Ac permanent magnet synchronous speed regulation is accomplished by changing frequency, need the inverter. Dc motor controller is don't need other equipment to help speed, but its complex structure, high manufacturing costs; Before the mass use of high power thyristor, dc motor used in most occasions of speed adjustment. In high power thyristor industrial production, the ac motor speed control easier, ac motor of low manufacturing cost, long life and other advantages will show it. Three, speed regulation of dc motor controller methods advantages and disadvantages of different needs, different speed control method, it should be said that what is the distinguishing feature of each. 1. In a state of full magnetic field, the armature voltage, suitable for application in zero below the base speed range speed regulation. Can't meet the high speed of the motor controller. 2. In the armature voltage state, the driving voltage, suitable for application in the speed above, weak magnetic speed. Can't get low rotate speed of motor controller. 3. In a state of full magnetic field, the armature voltage, the armature after full voltage, weak magnetic speed. Suitable for application in the case of large range of speed. This is the most perfect mode of speed control dc motor controller, but the equipment complex, high cost. Company production of dc motor controller, motor controller of brushless dc motor controller series, dc servo motor controller series products, welcome consultation 15118744777 Pan Gong