Abstract : This paper introduces the principle of PWM technology and the characteristics of integrated PWM power amplifier modules, points out several issues to be aware of in DC servo system applications, and analyzes the mechanism for improving the low-speed performance of servo systems. Keywords : Pulse Width Modulation (PWM) module, "Power Lubrication", Servo System 1 Introduction Power amplifiers are an important component of servo systems, directly affecting their performance. With the rapid development of power MOSFET technology, pulse width modulation (PWM) power amplifier technology is increasingly widely used in small and medium power servo systems. Its main characteristics are: a. Compared with linear power amplifiers, PWM power amplifiers are more efficient, have lower losses, are lighter, smaller in size, and require only a single power supply (without voltage regulation). b. In DC servo systems, due to the high switching frequency of the PWM power amplifier, a DC current with very small ripple and easy continuity can be obtained solely through the filtering effect of the motor armature, resulting in smooth and stable low-speed operation, achieving a speed ratio of 1:10000 in speed servo systems. Because PWM power amplifiers have fast response, strong dynamic anti-load interference capability, wide bandwidth, and no hysteresis or inertia, they are particularly suitable for high-speed positioning control and continuous control systems with reversible operation and frequent start-stop. c. DC servo motors driven by PWM are in a micro-motion state when the control signal is zero, which helps improve the system's static accuracy and low-speed performance. 2. Basic Principles of Amplifiers A pulse-width modulation (PWM) power amplifier consists of a voltage-to-pulse-width converter (including a triangular wave generator with strong voltage comparison), a driver, and a pulse amplifier. Its load is a DC servo motor. The principle block diagram is shown in Figure 1. [b][align=center]For more details, please click: Application of Pulse Width Modulation Technology in Servo Systems[/align][/b]