Patent ID: 8052863
Filing Date: 2011-11-08
Classification: G01N

Abstract:
1. A gas sensor control apparatus designed to control an operation of a gas sensor device equipped with a solid electrolyte body and a first and a second electrode affixed to opposed surfaces of the solid electrolyte body, comprising: a sensor current sampling resistor connected in series to a first terminal that is one of a positive and a negative terminals which leads to the first electrode of the gas sensor device; a first voltage supply circuit configured to develop a first voltage based on a first reference voltage at the first terminal leading to the gas sensor device through said sensor current sampling resistor; a second voltage supply circuit configured to develop a second voltage based on a second reference voltage at a second terminal that is other of the positive and negative terminals which leads to the second electrode of the gas sensor device; and a controller configured to sample through said sensor current sampling resistor a sensor current that is an electric current flowing through the gas sensor device upon application of voltage across the gas sensor device through the first and second terminals resulting from development of the first and second voltage at the first and second terminals and to produce a signal based on the sensor current which is a function of concentration of a given gas, when it is required to measure an impedance of the gas sensor device, said controller alternating the first voltage across the first reference voltage and sampling and outputting a resulting change in the sensor current as representing the impedance of the gas sensor device; wherein said second voltage supply circuit is configured to amplify the sensor current, as sampled through said sensor current sampling resistor, to control the second voltage, as developed at the second terminal.