Instrument interfacing method and device thereof

Patent metadata

Field	Value
Publication number	US-11714115-B2
Application number	US-202117625768-A
Country	US
Kind code	B2
Filing date	Mar 11, 2021
Priority date	Mar 24, 2020
Publication date	Aug 1, 2023
Grant date	Aug 1, 2023

Abstract

An instrument interface method and device. Two capacitors, one capacitor has one end as input of the device, connected to live line of power output of a LISN, and has other end as output of the device, connected to one test port of an oscilloscope; the other capacitor has one end as input of the device, connected to neutral line of the power output of the LISN, and has other end as output of the device, connected to another test port of the oscilloscope; without changing the LISN design, existing LISN products can be used for conducted emission test with oscilloscope-based time-domain EMI measurement instruments by means of the method and device. Said two capacitors have a capacity of <0.09 μF, which reduced the requirements of oscilloscope's A/D conversion, making low-cost oscilloscope can also be used for EMI testing.

First claim

The invention claimed is:

1. A method of instrument interface, wherein the method comprises:
connecting power output of a Line Impedance Stabilization Network (LISN), to one end of a capacitor, and connecting other end of the capacitor to test port of an instrument; the capacitor having a capacity<0.09 μF.

2. The method according to claim 1 , wherein the power output of the LISN comprises either a live line or a neutral line.

3. The method according to claim 1 , wherein said connecting other end of the capacitor to test port of an instrument, comprises connecting to the test port of an instrument through a resistor.

4. The method according to claim 1 , wherein said connecting other end of the capacitor to test port of an instrument, comprises connecting to the test port of an instrument directly.

5. The method according to claim 1 , wherein the other end of the capacitor is connected to one end of a resistor, and other end of the resistor is connected to earth or protective earth; where the resistor is an option.

6. A device of instrument interface, wherein the device comprises:
two capacitors, one capacitor has one end as input of the device, connected to live line of power output of a Line Impedance Stabilization Network (LISN), and has other end as output of the device, connected to one test port of an instrument; the other capacitor has one end as input of the device, connected to neutral line of the power output of the LISN, and has other end as output of the device, connected to another test port of the instrument; said two capacitors have a capacity of <0.09 μF.

7. The device according to claim 6 , wherein said device is self-contained and connected to the LISN and the instrument.

8. The device according to claim 6 , wherein said device is integrated with LISN to form a LISN with function of interfacing with the instrument.

9. The device according to claim 8 , wherein LISN with function of interfacing with the instrument can be used not only for conventional spectrum-based Electromagnetic Interference (EMI) testing, but also for oscilloscope-based EMI testing.

Assignees

• Wu Wei

Inventors

• Wu Wei
• Wu Yuejia

Classifications

• G01R31/001 Primary

  Measuring interference from external sources to, or emission from, the device under test, e.g. EMC, EMI, EMP or ESD testing (measuring electromagnetic fields G01R29/08; circuits for generating HV pulses in dielectric strength testing G01R31/14) · CPC title

• G01R1/0408

  Test fixtures or contact fields; Connectors or connecting adaptors; Test clips; Test sockets (G01R1/067 takes precedence; mass production testing systems G01R31/59; testing of connections G01R31/66; for testing printed circuit boards G01R31/2808) · CPC title

• G01R1/0416

  Connectors, terminals (G01R1/0425 and G01R1/0433 take precedence; with measurement function for battery poles G01R31/364) · CPC title

• G01R1/20

  Modifications of basic electric elements for use in electric measuring instruments; Structural combinations of such elements with such instruments · CPC title

• G01R1/36

  Overload-protection arrangements or circuits for electric measuring instruments · CPC title