SENSOR MONITORING METHOD AND SENSOR PROVIDED WITH EVALUATION CIRCUIT

• Main Authors: SCHENK RENE, BIESTER JUERGEN, BERGER JOACHIM
• Format: Patent
• Language: English
• Published: 13.10.2000
• Edition: 7
• Subjects: ALARM SYSTEMS; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; MEASURING; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; ORDER TELEGRAPHS; PHYSICS; SIGNALLING; SIGNALLING OR CALLING SYSTEMS; TARIFF METERING APPARATUS; TESTING; TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILARSIGNALS

PROBLEM TO BE SOLVED: To evaluate a sensor output signal at arbitrary prescribed time based on a prescribed test signal by detecting the signal of a prescribed trigger level in a sensor and supplying the test signal to a sensor output side. SOLUTION: A sensor 1 is connected to an evaluation/control unit 2 through three lines, namely, two power feeding voltage lines 11 and an output voltage line 3. A processor 5 is which connected to the back end of an analog/digital converter 4 controls a transistor switch 6. The transistor switch 6 supplies a trigger signal, positive operation voltage, for example, to the output side line 3. Since the output current of an operational amplifier 10 which is connected to the back end of a sensor element 9 is limited, a comparator 7 can identify the trigger signal and therefore the comparator 7 starts a test unit based on the signal. A test signal conducted to the sensor output side in a test phase can evaluate whether disconnection or shorting occurs or not in the evaluation unit 2.