Patent ID: 6612737
Filing Date: 2003-09-02
Classification: G01K

Abstract:
A measurement system, comprising:a first reference device constructed and arranged to produce a first reference current; a second reference device constructed and arranged to produce a second reference current; a linear sensing device constructed and arranged to produce a measurement current indicative of a value to be measured; a current-to-frequency converter constructed and arranged to convert the first reference current, the second reference current, and the measurement current to their corresponding frequency; a multiplexer constructed and arranged to alternately couple said current-to-frequency converter to said first reference device, said second reference device, and said linear sensing device; a voltage-to-frequency converter; a voltage input on said voltage-to-frequency converter; a reference voltage output from said voltage-to-frequency converter; and a pair of resistors arranged to divide a reference voltage from said reference voltage output of said voltage-to-frequency converter; wherein: said current-to-frequency converter includes said voltage-to-frequency converter configured so that an output frequency of said current-to-frequency converter varies with the measurement current input into said current-to-frequency converter; said pair of resistors supply the reference voltage to said voltage input on said voltage-to-frequency converter; and said voltage-to-frequency converter provides a constant output voltage to said first reference device, said second reference device, and said linear sensing device based on the reference voltage.