Method and device for detecting the temperature of the vibrating element of an ultrasonic converter
AssigneeElmos Semiconductor AG
InventorEgbert Spiegel
Life of this patent
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Abstract
Disclosed is a method for detecting a value which represents the temperature of a vibrating element of an ultrasonic transducer. The ultrasonic transducer has a resonant frequency (fr). The method comprises the steps of operating the ultrasonic transducer with an electric measuring signal at a measuring frequency (fm) which is above the resonant frequency, and of detecting the absolute value of the complex impedance of the ultrasonic transducer at this measuring frequency (fm) and, building thereon, ascertaining the desired value, which is to represent the temperature of a vibrating element of an ultrasonic transducer, as a function of the detected absolute value of the complex impedance of the ultrasonic transducer at this measuring frequency (fm).
Claims20
A method for ascertaining a temperature of a vibrating element of an ultrasonic converter having a resonant frequency, the method comprising:
- operating the ultrasonic converter with a measuring signal having a frequency that is at least 0.2 times the resonant frequency greater or smaller than the resonant frequency;
- ascertaining a complex impedance of the ultrasonic converter upon activation by way of the measuring signal having the frequency, and determining an absolute value of the complex impedance;
- and
- ascertaining, based on a level of the absolute value of the complex impedance and the frequency of the measuring signal for operating the ultrasonic converter, the temperature of the vibrating element of the ultrasonic converter.
A device for ascertaining a temperature of a vibrating element of an ultrasonic converter having a resonant frequency, comprising:
- a measuring device for providing a measuring signal for at least partially activating the ultrasonic converter with a frequency that is at least 0.2 times the resonant frequency greater or smaller than the resonant frequency;
- wherein a level of a complex impedance of the ultrasonic converter arising upon activation of the ultrasonic converter with the measuring signal having the frequency that is at least 0.2 times the resonant frequency greater or smaller than the resonant frequency, and an absolute value thereof, can be ascertained by way of the measuring device;
- and
- an evaluation unit for ascertaining the temperature of the vibrating element of the ultrasonic converter based on the level of the absolute value of the complex impedance and the frequency of the measuring signal.
Dependencies are inferred from the claim text.