US 2008/0185289 A1 · Sensor control device

Abstract

A current detection resistance in a sensor control device is connected to a sensor element. The current flowing in the sensor element is detected through the current detection resistance. The current detection resistance is connected to an inverting amplification circuit for outputting an air/fuel output voltage to be transferred to a microcomputer. An offset setting circuit is connected to one input terminal of an operational amplifier in the inverting amplification circuit. The offset setting circuit is comprised of a switching element, a resistance connected in series to the switching element, and two dividing voltage resistances whose common node is connected to the resistance. The offset setting circuit generates and gives an offset to the A/F output voltage. The switching element is turned ON and OFF based on an offset switching signal transferred from the microcomputer.

Claims15

Dependent claims

A sensor control device for controlling the operation of a sensor element made up of solid polymer electrolyte capable of detecting a concentration of a specific gas component contained in a target gas in a wide detection range, comprising:

a current detection resistance for detecting a current flowing in the sensor element and generating an element current signal;
an amplification circuit for inputting the element current signal through one of positive and negative input signal terminals thereof, and for amplifying the element current signal;
an offset setting circuit for setting an offset, connected to a middle node between an input resistance and a feedback resistance in a feedback line for the amplification circuit;
and
offset switching means for switching the offset determined by the offset setting circuit according to the element current signal, which is continuously supplied from the sensor element, regarding the concentration of the specific gas component contained in the target gas.

2 more elements

A sensor control device for controlling the operation of a sensor element made up of solid polymer electrolyte capable of detecting a concentration of a specific gas component in a target gas in a wide detection range, comprising:

a current detection resistance for detecting a current flowing in the sensor element and generating an element current signal;
an amplification circuit of one of an inverting type and non-inverting type for inputting the element current signal through one input signal terminal thereof, and for amplifying the element current signal;
an offset setting circuit for setting an offset, which is connected to one of the one input signal terminal for receiving the element current signal and the other input signal terminal of the amplification circuit;
and
offset switching means for switching the offset determined by the offset setting circuit according to the element current signal regarding a concentration of the specific gas component contained in the target gas.

2 more elements

Dependencies are inferred from the claim text.

Sensor control device

Life of this patent

Sensor control device

Life of this patent

Abstract

Claims15