Digitizing electrical measurement system

Abstract

A scheme, including a microcomputer for measuring physical quantities of a passive component. A programmable sinusoidal signal generator is used for generating the test analog sinusoidal signal. An analog-to-digital conversion system has a first node coupled to the first node of a serial three terminals network, a second node coupled to a second node of a voltage follower or buffer, and a third node coupled to the microcomputer for delivering a second and a third digital sinusoidal signal to determine a physical quantity of a DUT (device under test) by the microcomputer based on the second, third digital sinusoidal signal and the resistance of the reference resistor.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a scheme for measuring the physical quantities, such as resistance, inductance or capacitance of a passive component, and specifically, to a digitizing electrical measurement scheme by using a digital signal processor (DSP) BACKGROUND OF THE INVENTION [0002] In general, all of the physical parameters of a passive component are not scalar, for example capacitor accompanying with a serial resistance and leakage resistance, inductor accompanying with a serial resistance and capacitance, and resistor accompanying with a capacitance and inductance. In general condition, each of the physical parameter of the passive component also includes another two physical parameters. Conventionally, an AC bridge is used to measure a passive component. For balancing the bridge to acquire an accurately measurement result, it needs to adjust that voltage of applying to the bridge and standard devices on the bridge. Such measuring method by u...

AI Technical Summary

Benefits of technology

[0007] The scheme for measuring physical quantities of a passive component comprises a digital signal processor for generating a first digital sinusoidal signal forming a digital data stream over a plurality of sampling cycles. A digital-to-analog converter is coupled to the digital signal processor for transforming the first digital sinusoidal signal into an analog sinusoidal signal. This sinusoidal signal acts as the test signal source. A serial three terminals network has a reference resistor allowing for connecting a DUT (device under test) , wherein the serial three terminals network has a first node connected to the digital-to-analog converter. A voltage follower or buffer has a first terminal connected to a second node of the serial three terminals network. A first switch has a first terminal connected to a second terminal of the voltage follower or buffer. A second switch has a first terminal connected to the first node of the serial three terminals network. An analog-to-digital converter has a first node connected to a second node of the first switch and the second switch, and a second node coupled to the digital signal processor for transforming the analog sinusoidal signals into a second and third digital sinusoidal signal to determine a physical quantity of the DUT (device under test) by the digital signal processor based on the second and third digital sinusoidal signal and the resistance of the reference resistor.

[0008] The scheme further comprises an active low pass filter having a first terminal coupled to the digital-to-analog converter and a second terminal connected to the first terminal of the serial three terminals network.

[0009] In other aspects, the scheme for measuring physical quantities of a passive component comprises a digital signal processor for generating a first digital sinusoidal signal forming a digital data stream over a plurality of sampling cycles. A digital-to-analog converter is coupled to the digital signal processor for transforming the first digital sinusoidal signal into an analog sinusoidal signal. A serial three terminals network has a plurality of parallel resistors allowing for connecting a DUT (device under test) by followed corresponding switches, wherein the serial three terminals network has a first node connected to the digital-to-analog converter. A voltage follower or buffer has a first terminal connected to a second node of the serial three terminals network. A first switch has a first terminal connected to a second terminal of the voltage follower or buffer. A second switch has a first terminal connected to the first node of the se

Problems solved by technology

Such measuring method by using the AC bridge results in higher cost and more complicated circuits.

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