Method and device for processing analogue output signals from capacitive sensors
First Claim
1. Method for processing an analogue output signal of a sensor, wherein the analogue sensor output signal comprises a carrier signal having a carrier frequency ω
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c and being modulated by a measurand detected by the sensor, wherein the method comprises;
sampling of the analogue sensor output signal using a sampling frequency ω
A to obtain a sampled sensor output signal having an amplitude which is proportional to the measurand detected by the sensor, wherein the sampling frequency ω
A of the sampling signal is set to be an integer divisor n of the carrier frequency ω
c, and wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the carrier signal ω
c.
1 Assignment
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Accused Products
Abstract
An analogue output signal of a sensor which comprises a carrier signal with a carrier frequency ωC which is modulated by a measurement size is sampled with a sampling frequency ωA to receive a sampled sensor output signal. The frequency ωA of the sampling signal is set so that it is an integer divisor n of the carrier frequency ωC, wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the sensor output signal. The sampled sensor output signal is filtered now to remove periodically repeated signal components from the sampled sensor output signal. Then a filtered useful signal is received, wherein its amplitude is proportional to the measurand detected by the sensor.
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Citations
21 Claims
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1. Method for processing an analogue output signal of a sensor, wherein the analogue sensor output signal comprises a carrier signal having a carrier frequency ω
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c and being modulated by a measurand detected by the sensor, wherein the method comprises;
sampling of the analogue sensor output signal using a sampling frequency ω
A to obtain a sampled sensor output signal having an amplitude which is proportional to the measurand detected by the sensor, wherein the sampling frequency ω
A of the sampling signal is set to be an integer divisor n of the carrier frequency ω
c, and wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the carrier signal ω
c. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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c and being modulated by a measurand detected by the sensor, wherein the method comprises;
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14. Processing device for providing a sampled sensor output signal, comprising:
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means for providing a carrier signal having a carrier frequency ω
c;a sensor for detecting a measurand and for outputting an analogue sensor output signal, wherein the carrier signal is supplyable to the sensor, wherein the analogue sensor output signal comprises the carrier signal having the carrier frequency ω
c, which is modulated by the measurand;means for providing a sampling signal having a sampling frequency ω
A, wherein the sampling frequency ω
A of the sampling signal is set so that the sampling frequency ω
A is an integer divisor n of the carrier frequency ω
c, and wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the carrier signal;sampling means for sampling the analogue sensor output signal using the sampling signal to obtain the sampled sensor output signal having an amplitude which is proportional to the measurand detected by the sensor. - View Dependent Claims (15)
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16. Method for processing an analogue output signal of a sensor, wherein the analogue sensor output signal comprises a carrier signal having a carrier frequency ω
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c and being modulated by a driver signal having a driver frequency ω
drive and by a measurand detected by the sensor, wherein the method comprises;sampling of the analogue sensor output signal using a sampling frequency ω
A to obtain a sampled sensor output signal being modulated by the driver signal and having an amplitude which is proportional to the measurand detected by the sensor, wherein the sampling frequency ω
A of the sampling signal is set to be an integer divisor n of the carrier frequency ω
c, and wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the carrier signal ω
c.
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c and being modulated by a driver signal having a driver frequency ω
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17. Method for processing an analogue output signal of a sensor, wherein the analogue sensor output signal comprises a carrier signal having a carrier frequency ω
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c and being modulated by a measurand, wherein the method comprises;
sampling of the analogue sensor output signal using a sampling frequency ω
A to obtain a sampled sensor output signal, wherein the sampling frequency ω
A of the sampling signal is set to be an integer divisor n of the carrier frequency ω
c, and wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the carrier signal ω
c;wherein the carrier signals are fed into the sensor at a center electrode of the same, wherein the sensor output signal is output to exterior electrodes of the sensor.
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c and being modulated by a measurand, wherein the method comprises;
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18. Method for processing an analogue output signal of a sensor, wherein the analogue sensor output signal comprises a carrier signal having a carrier frequency ω
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c and being modulated by a measurand, wherein the method comprises;
sampling of the analogue sensor output signal using a sampling frequency ω
A to obtain a sampled sensor output signal, wherein the sampling frequency ω
A of the sampling signal is set to be an integer divisor n of the carrier frequency ω
c, and wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the carrier signal ω
cwherein the carrier signals are fed into the sensor at exterior electrodes of the same, wherein the sensor output signal is output at a common electrode of the sensor.
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c and being modulated by a measurand, wherein the method comprises;
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19. Processing device for providing a sampled sensor output signal, comprising:
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means for providing a carrier signal having a carrier frequency ω
c;means for providing a driver signal having a driver frequency ω
drive;a sensor for detecting a measurand and for outputting an analogue sensor output signal, wherein the carrier signal and the driver signal are supplyable to the sensor, wherein the analogue sensor output signal comprises the carrier signal having the carrier frequency ω
c, which is modulated by the driver signal and by the measurand;means for providing a sampling signal having a sampling frequency ω
A, wherein the sampling frequency ω
A of the sampling signal is set so that the sampling frequency ω
A is an integer divisor n of the carrier frequency ω
c, and wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the carrier signal;sampling means for sampling the analogue sensor output signal using the sampling signal to obtain the sampled sensor output signal being modulated by the driver signal and having an amplitude which is proportional to the measurand detected by the sensor.
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20. Processing device for providing a sampled sensor output signal, comprising:
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means for providing a carrier signal having a carrier frequency ω
c;a sensor for detecting a measurand and for outputting an analogue sensor output signal, wherein the carrier signal is supplyable to the sensor, wherein the analogue sensor output signal comprises the carrier signal having the carrier frequency ω
c, which is modulated by the measurand;means for providing a sampling signal having a sampling frequency ω
A, wherein the sampling frequency ω
A of the sampling signal is set so that the sampling frequency ω
A is an integer divisor n of the carrier frequency ω
c, and wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the carrier signal;sampling means for sampling the analogue sensor output signal using the sampling signal to obtain the sampled sensor output signal having an amplitude which is proportional to the measurand detected by the sensor; wherein the carrier signals are fed into the sensor at a center electrode of the same, wherein the sensor output signal is output to exterior electrodes of the sensor.
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21. Processing device for providing a sampled sensor output signal, comprising:
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means for providing a carrier signal having a carrier frequency ω
c;a sensor for detecting a measurand and for outputting an analogue sensor output signal, wherein the carrier signal is supplyable to the sensor, wherein the analogue sensor output signal comprises the carrier signal having the carrier frequency ω
c, which is modulated by the measurand;means for providing a sampling signal having a sampling frequency ω
A, wherein the sampling frequency ω
A of the sampling signal is set so that the sampling frequency ω
A is an integer divisor n of the carrier frequency ω
c, and wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the carrier signal;sampling means for sampling the analogue sensor output signal using the sampling signal to obtain the sampled sensor output signal having an amplitude which is proportional to the measurand detected by the sensor; wherein the carrier signals are fed into the sensor at exterior electrodes of the same, wherein the sensor output signal is output at a common electrode of the sensor.
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Specification