Title of Invention | ISOLATED MEASAUREMENT CIRCUIT FOR SENSOR RESISTANCE |
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Abstract | The invention relates to measuring the resistance of a resistive sensor, such as a PTC or NTC temperature sensor used for monitoring the temperature of the windings of an electric motor. The invention is based on an electronic circuit in which conductors from a sensor located in the object to be monitored are connected to an amplifier circuit in a feedback configuration that reduces the DC level supplied to the voltage divider when the sensor resistance increases. The measured signal is amplified and, using a comparator to compare it with the output voltage of a sawtooth generator, a continuous PWM (Pulse Width Modulation) signal is generated and transmitted in digital format to a SELV electronic circuit, for example through an opto-isolator. The essentially logarithmic signal amplification makes it possible to reliably distinguish between a short circuit in the sensor circuit and low values of sensor resistance |
Full Text |
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4510-CHENP-2006 AMANDED CLAIMS 03-03-2010.pdf
4510-CHENP-2006 CORRESPONDENCE OTHERS 01-12-2009.pdf
4510-CHENP-2006 CORRESPONDENCE PO.pdf
4510-CHENP-2006 DESCRIPTION (COMPLETE) GRANTED.pdf
4510-CHENP-2006 EXAMINATION REPORT REPLY RECIEVED 03-03-2010.pdf
4510-CHENP-2006 FORM-1 08-12-2006.pdf
4510-CHENP-2006 FORM-3 03-03-2010.pdf
4510-CHENP-2006 POWER OF ATTORNEY.pdf
Patent Number | 239966 | |||||||||
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Indian Patent Application Number | 4510/CHENP/2006 | |||||||||
PG Journal Number | 17/2010 | |||||||||
Publication Date | 23-Apr-2010 | |||||||||
Grant Date | 16-Apr-2010 | |||||||||
Date of Filing | 08-Dec-2006 | |||||||||
Name of Patentee | ABB OY | |||||||||
Applicant Address | STROMBERGINTIE 1, FI-00380 HELSINKI, FINLAND | |||||||||
Inventors:
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PCT International Classification Number | G01K 7/22 | |||||||||
PCT International Application Number | PCT/FI05/00267 | |||||||||
PCT International Filing date | 2005-06-08 | |||||||||
PCT Conventions:
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