Patent ID: 9400198
Filing Date: 2016-07-26
CPC Classification: F02D,G01F

Claim Text:
1. A flow sensor, comprising: a fluid temperature detection portion that detects a temperature of a fluid; first and second heating elements that are disposed, respectively, upstream and downstream in a flow direction of the fluid so as to undergo mutual thermal interference; a first control portion that controls heating currents flown through the respective first and second heating elements so that an average temperature of the first and second heating elements is maintained at a temperature predetermined degrees higher than the temperature of the fluid detected by the fluid temperature detection portion; and a second control portion that controls the heating currents flown through the respective first and second heating elements so that one of a temperature difference between the first and second heating elements and a ratio between voltages applied to the respective first and second heating elements takes a predetermined value, wherein a detection signal corresponding to the flow direction of the fluid is obtained by the second control portion.