Patent ID: 8172199
Filing Date: 2012-05-08
Classification: F16K,G05D,H02P

Abstract:
1. A valve control apparatus for driving a valve for controlling the flow rate of a fluid flowing through a fluid channel, comprising: a stepping motor coupled to the valve; and a motor control unit for controlling the stepping motor, wherein the motor control unit comprises: a motor control section for applying drive pulses to the stepping motor; a counting section for counting the number of drive pulses applied to the stepping motor; a voltage-drop detecting section for detecting a voltage drop of a drive power supply which supplies an operating voltage for operating the motor control section; and a writing section for writing a count, which indicates the number of drive pulses counted by the counting section, in a nonvolatile memory when the voltage-drop detecting section detects the voltage drop, wherein the motor control unit is configured to control the stepping motor by having the motor control section apply drive pulses, upon activation of the valve control apparatus, to the stepping motor so that the valve is returned to an origin, the drive pulses corresponding to the count stored in the nonvolatile memory.