A Novel Noncontact Differential Method for Current and Voltage Measurements on a Printed Trace Simultaneously

Noncontact measurement of current and voltage poses various challenges in different applications. In this article, a novel differential reconstruction method for noncontact and simultaneous measurements of current and voltage as well as power on a printed trace is proposed. The principles and calculation procedures of the method are explained in detail. Compared with the previous segregated reconstruction method using a compact probe with both a current detector and voltage detector, the differential method employing a differential probe with a single-loop structure is well characterized through a series of comparison tests, including measured and calculated response tests, time delay difference tests, and reconstruction performance tests. Especially for time delay difference levels and the reconstruction performance, the proposed method is validated to exhibit a more than tenfold decrease in the time delay difference levels and a less than 5% average curve error. Finally, a real application involving the switching behaviors at the output of a customized pulsewidth modulation (PWM) generator module is presented with an average curve error of 3.8%. These results further support the feasibility and effectiveness of the proposed method.

I. Introduction

Noncontact measurement of current and voltage has become a fundamental and increasingly significant concern in recent years. In the modern industrial settings, accurately measuring the transient behavior of signals on a printed trace in an industrial module is crucial for ensuring the reliability and safety of the electronic modules [1], [2], [3], [4], [5]. By monitoring this data, effective fault prediction and diagnosis can be conducted. To prevent any impact on the original circuit structures, the related tests aim to simultaneously monitor trace voltage and current on a module board in a noncontact manner.