Patent ID: 8686746
Filing Date: 2014-04-01
Classification: G01R

Abstract:
1. A test apparatus used to measure common-mode capacitance between a first element and a second element being isolated from the first element, comprising: a signal generating device connected to the first element and having an internal signal source connected in series with a first internal impedance for sending a signal to the first element; and a signal receiving device directly connected between the second element and the first element and having a second internal impedance for measuring a signal response between the first element and the second element, thereby calculating the common-mode capacitance between the first element and the second element based on the signal response; wherein the first element includes a transformer primary winding and the second element includes a transformer secondary winding; wherein both the transformer primary winding and the transformer secondary winding are disposed in a phase-shift full-bridge converter; wherein the signal generating device is connected between a first hot-voltage point and a second hot-voltage point of the transformer primary winding and the signal receiving device is connected between a quiet point of the transformer secondary winding and the first hot-voltage point of the transformer primary winding.