Patent ID: 6508117
Filing Date: 2003-01-21
Classification: G01F

Abstract:
A bi-directional mass air flow sensing device for measuring air flow, comprising:a bridge circuit coupled across a voltage potential, wherein said bridge circuit comprises (a) a first side including first and second temperature dependent sensor resistors connected in series and disposed on a thermally insulative substrate window in line with an air flow and arranged such that relative to a first direction of air flow, the first sensor resistor is upstream of the second sensor resistor, and (b) a second side in parallel with the first side and including third and fourth temperature dependent sensor resistors connected in series and disposed on the thermally insulative substrate in line with the air flow such that relative to the first direction of air flow, the third sensor resistor is upstream of the fourth sensor resistor, and (c) a temperature dependent balance resistor connected between the first and second temperature dependent sensor resistors on the first side of the bridge circuit.