Patent ID: 6386030
Filing Date: 2002-05-14
Classification: G01F

Abstract:
A temperature regulator for an air-mass meter in an air intake manifold of an internal combustion engine comprising a bridge circuit having a first branch including a measuring resistor having a temperature-dependent variable resistance for detecting ambient temperature, and a second branch including a heating resistor having a temperature-dependent variable resistance, said first and second branches having central taps, a bridge null branch connected to said central taps, said bridge null branch including an operational amplifier having positive and negative inputs connected to said central taps to correct any bridge imbalance based on any voltage difference in the bridge null branch, means connected in front of said measuring resistor for reducing voltage supplied to said measuring resistor by a factor k, and further means in the second bridge branch after the heating resistor for reducing voltage in said second branch by said factor k to maintain bridge balance, wherein said means for reducing voltage supplied to said measuring resistor comprises a voltage divider including first and second resistors and a voltage follower connected in front of said measuring resistor in series with the first resistor of the voltage divider, the second resistor of said voltage divider being connected in parallel to said voltage follower and to said measuring resistor.