GAS SENSOR CONTROL SYSTEM ENSURING INCREASED MEASUREMENT ACCURACY
First Claim
1. A gas sensor control system for controlling an operation of a gas sensor equipped with a sensing device including a first cell, a second cell, and a third cell which are each made of a solid electrolyte and a gas chamber formed therein, the first cell working to control an amount of oxygen contained in a gas admitted into the gas chamber to keep a concentration of oxygen in the gas at a given controlled level, the second cell working to produce an electric current as a function of a concentration of oxygen contained in the gas in which the amount of oxygen has been controlled by the first cell, the third cell working to produce an electric current as a function of a concentration of a preselected component of the gas in which the amount of oxygen has been controlled by the first cell, comprising:
- a second cell circuit including a current-to-voltage converter which is connected to the second cell to sample and convert the electric current, as produced by the second cell, into a voltage and outputs the voltage as a second cell current-measured value;
a third cell circuit including a current-to-voltage converter which is connected to the third cell;
a current adjuster working to produce an adjustment current that is an electric current determined as a function of the second cell current-measured value, as outputted from said second cell circuit; and
a branch circuit path which is connected to a junction between the current-to-voltage converter of the third cell circuit and the third cell and through which the adjustment current flows to input the electric current, as produced by the third cell, minus the adjustment current into the current-to-voltage converter of the third cell circuit, so that the current-to-voltage converter converts the electric current minus the adjustment current into a voltage and outputs the voltage as a third cell current-measured value representing the concentration of the preselected component of the gas.
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Accused Products
Abstract
A gas sensor control system for a gas sensor having a first, a second, and a third cell. The second cell produces a second cell electric current indicating the concentration of oxygen in gas in which the amount of oxygen has already been controlled by the first cell. The third cell produces a third cell electric current indicating the concentration of a preselected component of the gas in which the amount of oxygen has already been controlled by the first cell. A second cell circuit converts the second cell electric current into a voltage as a second cell current-measured value. A current adjuster produces a flow of an adjustment current as a function of the second cell current-measured value so that a third cell circuit converts the third cell electric current minus the adjustment current into a voltage as representing the concentration of the preselected component of the gas.
14 Citations
6 Claims
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1. A gas sensor control system for controlling an operation of a gas sensor equipped with a sensing device including a first cell, a second cell, and a third cell which are each made of a solid electrolyte and a gas chamber formed therein, the first cell working to control an amount of oxygen contained in a gas admitted into the gas chamber to keep a concentration of oxygen in the gas at a given controlled level, the second cell working to produce an electric current as a function of a concentration of oxygen contained in the gas in which the amount of oxygen has been controlled by the first cell, the third cell working to produce an electric current as a function of a concentration of a preselected component of the gas in which the amount of oxygen has been controlled by the first cell, comprising:
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a second cell circuit including a current-to-voltage converter which is connected to the second cell to sample and convert the electric current, as produced by the second cell, into a voltage and outputs the voltage as a second cell current-measured value; a third cell circuit including a current-to-voltage converter which is connected to the third cell; a current adjuster working to produce an adjustment current that is an electric current determined as a function of the second cell current-measured value, as outputted from said second cell circuit; and a branch circuit path which is connected to a junction between the current-to-voltage converter of the third cell circuit and the third cell and through which the adjustment current flows to input the electric current, as produced by the third cell, minus the adjustment current into the current-to-voltage converter of the third cell circuit, so that the current-to-voltage converter converts the electric current minus the adjustment current into a voltage and outputs the voltage as a third cell current-measured value representing the concentration of the preselected component of the gas. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification