Gas Sensor Control Device Preventing Overvoltage Damage

Solution Overview

Problem

Gas sensor elements with solid electrolyte bodies can be damaged due to overvoltage when a reference generation current is applied before they are fully activated, especially when the heating is insufficient, leading to difficulties in reaching the required current flow through the oxygen concentration detection cell with high impedance.

Innovation Solution

A sensor control device that includes a damage avoidance time elapse determining unit and a reference generation current application permitting unit, which prevents the flow of reference generation current until the gas sensor element is adequately heated, thereby preventing overvoltage and potential damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a reference generation current is applied to the oxygen concentration detection cell before the gas sensor element is fully activated, then the oxygen reference pole can be established, but the gas sensor element may be damaged due to overvoltage

Engineering Contradiction:

Improveestablishment of oxygen reference poleVSAvoidovervoltage damage to gas sensor element

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The control device performs preliminary heating of the gas sensor element before applying the reference generation current. The heating control unit activates the heater to raise the temperature of the solid electrolyte body to a predetermined temperature threshold before the oxygen reference pole generating unit applies the reference generation current, ensuring the sensor is activated and ready to handle the current without damage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control device uses feedback from the temperature detection unit to monitor the temperature of the gas sensor element. The heating control unit continuously adjusts the heating based on the detected temperature, and the current application control unit uses this temperature feedback to determine the appropriate timing for applying the reference generation current, ensuring it is only applied when the temperature threshold is met.

Inventive Principle:

Principle #23Feedback

2Reliability

If heating of the gas sensor element is insufficient, then the gas sensor element cannot be activated, but applying reference generation current anyway causes high impedance and overvoltage

Engineering Contradiction:

Improveactivation of gas sensor elementVSAvoidvoltage across oxygen concentration detection cell

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The control device performs preliminary heating of the gas sensor element before applying the reference generation current. The heating control unit activates the heater to raise the temperature of the solid electrolyte body to a predetermined temperature threshold before the oxygen reference pole generating unit applies the reference generation current, ensuring the sensor is activated and ready to handle the current without damage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control device uses feedback from the temperature detection unit to monitor the temperature of the gas sensor element. The heating control unit continuously adjusts the heating based on the detected temperature, and the current application control unit uses this temperature feedback to determine the appropriate timing for applying the reference generation current, ensuring it is only applied when the temperature threshold is met.

Inventive Principle:

Principle #23Feedback

3Loss of time

If the reference generation current is applied too early, then measurement can begin sooner, but the gas sensor element may blacken and become damaged

Engineering Contradiction:

Improvetime to begin measurementVSAvoidblackening and damage of gas sensor element

Core Design Contradiction:

Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The control device performs preliminary heating of the gas sensor element before applying the reference generation current. The heating control unit activates the heater to raise the temperature of the solid electrolyte body to a predetermined temperature threshold before the oxygen reference pole generating unit applies the reference generation current, ensuring the sensor is activated and ready to handle the current without damage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control device uses feedback from the temperature detection unit to monitor the temperature of the gas sensor element. The heating control unit continuously adjusts the heating based on the detected temperature, and the current application control unit uses this temperature feedback to determine the appropriate timing for applying the reference generation current, ensuring it is only applied when the temperature threshold is met.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS8182664B2Sensor control device

Publication Date: 2012.05.22 NITERRA CO LTD

AI summary

A sensor control device for controlling a current application state of a gas sensor element when measuring a specific gas component concentration in a gas to be measured using the gas sensor element, which sensor control device includes: at least one cell having a solid electrolyte body and a pair of electrodes; a sensor heating unit as defined herein; an oxygen reference pole generating unit as defined herein; a damage avoidance time elapse determining unit as defined herein; and a reference generation current application permitting unit as defined herein.