A Study on PWM Parameters Range of on-off Electromagnetic Valve in Fluid Control Systems

Abstract

On-off electromagnetic valve driven by pulse width modulation (PWM) is used for adjustment of flow in fluid control systems. The parameters of a basic PWM driver include operating voltage, duty ratio and frequency. Regularly, operating voltage is fixed and given by manufactory, users can adjust PWM frequency and duty ratio to control flow and flow characteristics. Flow deviation led by unsuitable parameters selection results in deterioration of performance in fluid control system. By measuring flow-frequency data at a fixed duty ratio and flow-duty ratio data at a fixed frequency, this study revealed that in the frequency range of 45-105Hz under a fixed duty ratio at 50% or in the duty ratio range of 10% -90% by fixing frequency at 50Hz, the tested on-off electromagnetic valve possesses good linearity. This result provides references for the design of PWM driver.