Adjustable time constant integrator
AssigneeNational Instruments Corporation
InventorPaul A. Lennous
Life of this patent
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Abstract
A variable time constant integrator includes an amplifier configured to generate an output signal, a capacitor coupled to provide feedback to the amplifier, and a variable gain element coupled to the output of the amplifier and to the capacitor. The variable gain element is configured to provide the product of a gain and the output signal to the capacitor. The variable gain element is also configured to receive an indication of a new value of the gain and to responsively set the gain equal to the new value of the gain. Adjusting the gain of the variable gain element adjusts the integrator's time constant.
Claims15
A variable time constant integrator comprising:
- an amplifier configured to generate an output signal;
- a capacitor coupled to provide feedback to the amplifier;
- a variable gain element coupled to an output of the amplifier and to the capacitor,
- wherein the variable gain element is configured to provide a product of a gain and the output signal to the capacitor;
- wherein the variable gain element is configured to receive an indication of a new value of the gain and to responsively set the gain equal to the new value of the gain.
An instrumentation system comprising:
- a transducer configured to convert one or more physical phenomena to an input signal;
- a signal conditioning subsystem coupled to receive the input signal from the transducer, wherein the signal conditioning subsystem comprises a filter configured to process the input signal;
- wherein the filter comprises one or more variable time constant integrators, wherein each variable time constant integrator comprises:
- an amplifier;
- a capacitor coupled to provide feedback to the amplifier;
- a variable gain element coupled to an output of the amplifier and to the capacitor, wherein the variable gain element is configured to provide a product of a gain and an output signal from the amplifier to the capacitor, wherein the variable gain element is configured to receive an indication of a new value of the gain and to responsively set the gain equal to the new gain.
A method of adjusting an integrator's time constant, wherein the integrator comprises an amplifier and a capacitor coupled in a feedback path of the amplifier, the method comprising:
- adjusting a gain of a variable gain element to equal a new gain, wherein the variable gain element is coupled to the capacitor and to an output of the amplifier, wherein the variable gain element is configured to receive an output signal from the amplifier;
- the variable gain element providing a signal equal to a product of the output signal and the new gain to the capacitor.
A controller comprising:
- input circuitry configured to receive a set input and an error input and to output a first signal;
- an integrator coupled to the input circuitry and configured to process the first signal, wherein the integrator includes:
- an amplifier;
- a capacitor coupled to provide feedback to the amplifier;
- and
- a variable gain element coupled to an output of the amplifier and to the capacitor;
- wherein the variable gain element is configured to provide a product of a gain and an output signal from the amplifier to the capacitor, wherein the variable gain element is configured to receive an indication of a new value of the gain and to responsively set the gain equal to the new gain.
Dependencies are inferred from the claim text.