Circuit arrangement for monitoring an electronic switch controlling a load

US6400163B1 · kind B1 · utility

Inventors

• Rolf Melcher · Karlsruhe, DE
• Siegfried Seliger · Dortmund, DE

Key dates

• Filing date: Sep 8, 2000
• Grant date: Jun 4, 2002
• Expiry date: Nov 23, 2020

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R31/3277
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

In a circuit arrangement for monitoring an electronic switch provided for controlling a load and current flown through the load during turn-on intervals for driving the load, the switch has a substantially linear resistance behavior during parts of its turn-on state and the operating point of the switch is located in this part of the turn-on state during the load control. The circuit arrangement comprises a modulation signal generator for generating a modulation signal for modulating the load current flowing through the electronic switch. A first voltage measuring device measures the first voltage drop across the electronic switch caused by the modulation signal. A second voltage measuring device measures the voltage drop across the electronic switch caused by the load current, and an evaluation unit determines the load current from the modulation signal and the first and second voltage drops.