What is the principle of a servo amplifier?

A servo amplifier consists of functional modules such as command and feedback comparison processing, zero-setting circuit, current-limiting circuit, pre-amplifier, and power amplifier. The function of the preamplifier circuit is to compare and amplify the command and feedback input signals. The function of the zero-setting circuit is to adjust the circuit’s reference voltage by applying an adjustable voltage to the preamplifier circuit. Bias in the servo amplifier system is overcome by adjusting potentiometers for zero-offset compensation. 　　 The function of a current-limiting circuit is to limit the maximum current flowing through the solenoid of the servo valve, preventing overload of the solenoid and protecting the servo valve, as well as restricting the maximum flow rate in the hydraulic system. The function of a power amplification circuit is to convert and amplify low-power voltage signals into current signals with higher power, so as to provide sufficient rated current for the servo valve to drive the load.