Flow rate controlling using phase-locked loop

Abstract

This paper proposes controlling flow rate by using Phase-Locked Loop (PLL) to control the voltage output of power amplifier sent to the DC pump. With this technique, the flow rate of liquids in the pipe connected to such pump can be easily adjusted. With the property of PLL, the frequency of output signal of the flow sensor, which is proportional to the flow rate, is synchronized with that of the reference input. As a result, the flow rate remains constant. In addition, the experiment results show that the flow rate is not affected by the varying loads, i.e., the flow rate is stable to perturbations. © 2013 ICIC International.