Electrical assembly and measurement circuit and method for monitoring a component thereof

• US 10,627,434 B2
• Filed: 04/08/2016
• Issued: 04/21/2020
• Est. Priority Date: 04/09/2015
• Status: Active Grant

• Current Assignee: Weidmã¼Ller Interface GmbH & Company KG (WEIDMÜLLER Holding AG & Co. KG)
• Original Assignee: Weidmã¼Ller Interface GmbH & Company KG (WEIDMÜLLER Holding AG & Co. KG)
• Inventors: Paiz Gatica, Carlos, Schindler, Rico
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): Curtis, Sean
• Application Number:
  US15/561,651
• Publication Number:
  US 20180074100A1
• Time in Patent Office: 1,474 Days
• Field of Search: 324421
• CPC Class Codes: G01R 27/08 Measuring resistance by measuring both voltage and current
• CPC Class Codes: G01R 31/14 Circuits therefor , e.g. for generating test voltages, sensing circuits G01R31/1209 - G01R31/1227 take precedence; for testing switches G01R31/327
• CPC Class Codes: G01R 31/42 AC power supplies
• CPC Class Codes: H02M 1/096 the power supply of the control circuit being connected in parallel to the main switching element H02M1/092 takes precedence
• CPC Class Codes: H02M 3/33507 with automatic control of the output voltage or current, e.g. flyback converters H02M3/33561, H02M3/33569 take precedence

Abstract

A measuring method is provided for monitoring a component of an electrical assembly, in which the voltage across at least one component of the electrical assembly and a current through the component are measured, and in which, from measurement values for the voltage and the current, a resistance value of the component is determined. The voltage and the current are measured in successive switching periods of a periodic switching signal of the electrical assembly, and the resistance value is determined based on the measurement values for voltage and current from the successive switching periods. A measuring circuit for monitoring a component of an electrical assembly is provided with an analog/digital converter. An electrical assembly, in particular a switching power supply, having such a measuring circuit is also provided.

Claims

1. A measurement circuit for monitoring components of an electrical assembly, comprising an analog/digital converter, a multiplexer for connecting said analog/digital converter with the electrical assembly to selectively measure at least one of the voltage across and the current through at least one component, a voltage-limiting circuit connected upstream of said multiplexer to limit an input voltage to a maximum value, and a synchronization device connected between said voltage-limiting circuit and said multiplexer to measure at least one of the voltage and current synchronized with a periodic switching signal from the electrical assembly.

2. The measurement circuit as defined in claim 1, wherein the voltage and the current are measured in successive switching periods of the periodic switching signal to determine a resistance value on the basis of measured values of voltage and current measured at comparable times within successive switching periods.

3. An electrical assembly comprising a measurement circuit as defined in claim 1 for measuring a resistance value of a component of the electrical assembly during the operation of the electrical assembly.

4. The electrical assembly as defined in claim 3, and further comprising a switching power supply and a switching converter including a switching transistor, wherein the measurement circuit measures a resistance of the switching transistor.

5. The electrical assembly as defined in claim 4, and further comprising a primary filter stage connected between said switching power supply and said switching converter, said primary filter stage including a capacitor, and wherein said measurement circuit measures an equivalent series resistance of said capacitor.