High current Kelvin connection and verification method

摘要

A method and circuit for implementing high current capability Kelvin connections and measuring the resistance of the contacts and connections to verify that the conducting path is capable of carrying the high current without damage or degraded performance. Included as well is the means and circuit for efficiently dividing a high current test stimulus current into 2 paths with low losses and voltage drops.

主权项

1. A device for measuring impedance of a Kelvin connection to a circuit of interest and for injecting a test stimulus into the circuit of interest, comprising:
a first transformer having a primary winding and a secondary winding, wherein the secondary winding comprises a first winding part having a first end and a second winding part having a second end, the first winding part connected to the second winding part via a center tap; a first input device for receiving a Kelvin test input waveform, the first input device electrically coupled to the primary winding; a second input device for receiving the test stimulus, the second input device electrically connected to the center tap of the secondary winding; first and second test leads for connection to the circuit of interest, the first and second test leads electrically connected to the first end and the second end, respectively, of the secondary winding; a sensing device electrically coupled to the primary winding, the sensing device operative to provide a measurement corresponding to a contact impedance between the first and second test leads based on impedance reflected from the secondary winding to the primary winding in response to application of the Kelvin test input waveform to the first input device and the test stimulus.