Patent ID: 8800592
Filing Date: 2014-08-12
Classification: G05D,Y10T

Abstract:
1. A flow control device, comprising: a valve unit that controls a flow of a fluid inside a flow path; a flow volume sensor that outputs a sensor output signal according to a flow volume of the fluid; a comparator that receives (i) an instruction value signal expressing the instruction value of the flow volume of the fluid as a first input signal and (ii) a signal according to the sensor output signal as a second input signal, and outputs a first control voltage based on a comparison of the first and second input signals; a feedback current generating unit that generates a feedback current according to a difference between (i) the sensor output signal or a signal according to the sensor output signal and (ii) a signal according to the instruction value signal; a feedback voltage generating unit that generates a feedback voltage according to the feedback current; a feed forward current generating unit that generates a feed forward current according to the instruction value signal; and a synthesis unit that generates a second control voltage that is a voltage obtained by adding to the feedback voltage a voltage according to a sum of the feedback current and the feed forward current, wherein the valve unit is controlled according to the first control voltage and the second control voltage.