# US 9,752,958 B2 · Load drive apparatus and sensor control apparatus

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- Number: US 9,752,958 B2
- Document ID: US9752958B2
- Status: Granted
- Kind: B2
- Application number: 14/481,210
- Filed: 2014-09-09
- Published: 2015-03-12
- Granted: 2017-09-05
- Earliest claimed: 2013-09-10
- Assignees: Ngk Spark Plug Co., Ltd.
- Applicants: Ngk Spark Plug Co., Ltd.
- Inventors: Katsunori Yazawa; Yoshinori Inoue
- Web page: https://patentgrep.com/patent/US9752958B2

## CPC

- F01N 11/00: Monitoring or diagnostic devices for exhaust-gas treatment apparatus
- F02D 41/221: {relating to the failure of actuators or electrically driven elements}
- F02D 41/222: {relating to the failure of sensors or parameter detection devices}
- F02P 19/022: {using intermittent current supply}
- F02P 19/027: {Safety devices, e.g. for diagnosing the glow plugs or the related circuits}
- G01M 15/104: {using oxygen or lambda-sensors (testing catalytic converters F01N3/18, F01N11/007)}
- G01R 31/50: Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections (testing of sparking plugs H01T13/58)
- F01N 2550/00: Monitoring or diagnosing the deterioration of exhaust systems
- F01N 2560/025: for measuring or detecting O2, e.g. lambda sensors
- F01N 2560/20: Sensor having heating means
- F01N 2900/0602: Electrical exhaust heater signals
- G01R 31/40: Testing power supplies (testing photovoltaic devices H02S50/10)
- H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators
- Y02T 10/40: Engine management systems
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00)
- G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A load drive apparatus (1) includes a pulse drive circuit (51) which applies a pulse voltage PS to a resistive load (4); current detection means (S14) for detecting the current flowing to the resistive load (4) through the pulse drive circuit (51); level detection means (S1, S7) for determining whether an output terminal voltage VD of the pulse drive circuit (51) is a high potential level or a low potential level; anomaly detection means (S8, S9, S18) for detecting a wire breakage anomaly, a short-to-power anomaly, and a short-to-ground anomaly based on the level of the output terminal voltage VD detected by the level detection means (S1, S7) and the current detected by the current detection means (S14), when the pulse drive circuit 51 is turned on and off.

## Claims

### Claim 1

A load drive apparatus comprising:
a pulse drive circuit which has an output terminal connected to a second end of a resistive load whose first end is grounded, the pulse drive circuit being disposed between the resistive load and a power supply, the pulse drive circuit repeatedly applying a pulse voltage to the resistive load by repeatedly turning the pulse drive circuit on and off;
current detection means for detecting a current flowing from the power supply to the resistive load through the pulse drive circuit when the pulse drive circuit turns on;
level detection means for determining whether an output terminal voltage at the output terminal of the pulse drive circuit is at a high potential level or a low potential level; and
anomaly detection means for detecting a wire breakage anomaly, a short-to-power anomaly, and a short-to-ground anomaly based on the level of the output terminal voltage detected by the level detection means and the current detected by the current detection means when the pulse drive circuit is turned on and off,
the wire breakage anomaly being an anomaly in which at least one of a first connection path which connects the output terminal of the pulse drive circuit and the second end of the resistive load and a second connection path which grounds the first end of the resistive load is broken,
the short-to-power anomaly being an anomaly in which the first connection path is short-circuited to a power supply potential, and
the short-to-ground anomaly being an anomaly in which the first connection path is short-circuited to a ground potential.

### Claim 2 (depends on 1)

The load drive apparatus as claimed in claim 1, wherein the anomaly detection means includes:
wire-breakage determination means for determining that a wire breakage anomaly has occurred, when the level of the output terminal voltage changes between the high potential level and the low potential level as a result of turning the pulse drive circuit on and off, and the current flowing to the resistive load detected by the current detection means when the pulse drive circuit is turned on is smaller than a predetermined lower limit current value;
short-to-power determination means for determining that a short-to-power anomaly has occurred, when the level of the output terminal voltage remains at the high potential level irrespective of turning the pulse drive circuit on and off; and
short-to-ground determination means for determining that a short-to-ground anomaly has occurred, when the level of the output terminal voltage remains at the low potential level irrespective of turning the pulse drive circuit on and off.

### Claim 3 (depends on 1)

The load drive apparatus as claimed in claim 1, wherein the anomaly detection means comprises energization period anomaly detection means for detecting a wire breakage anomaly, a short-to-power anomaly, and a short-to-ground anomaly by turning the pulse drive circuit on and off during a pulse energization period during which the pulse voltage is repeatedly applied to the resistive load.

### Claim 4 (depends on 1)

The load drive apparatus as claimed in claim 1, further comprising energization stoppage means for stopping the supply of electric current to the resistive load by the pulse drive circuit when the anomaly detection means detects any of a wire breakage anomaly, a short-to-power anomaly, and a short-to-ground anomaly.

### Claim 5 (depends on 4)

A sensor control apparatus which comprises the load drive apparatus as claimed in claim 4, said sensor control apparatus controlling a sensor including a heater which is the resistive load and which generates heat when energized by the load drive apparatus and a detection element formed of solid electrolyte and heated by the heater, the sensor control apparatus comprising:
an element drive circuit for driving the detection element of the sensor; and
element drive stoppage means for stopping the drive of the detection element by the element drive circuit when the anomaly detection means of the load drive apparatus detects any of a wire breakage anomaly, a short-to-power anomaly, and a short-to-ground anomaly.

### Claim 6 (depends on 5)

The sensor control apparatus according to claim 5, wherein the sensor is a gas sensor which has, as the detection element, a gas detection element including a pump cell which is formed of an oxygen-ion-conductive solid electrolyte and pumps oxygen into or out of a measurement chamber of the gas detection element in accordance with a pump current flowing through the pump cell;
the element drive circuit includes a pump current control circuit for supplying the pump current to the pump cell; and
the element drive stoppage means includes pump current stoppage means for causing the pump current control circuit to stop the supply of the pump current to the pump cell.