Patent ID: 8872522
Filing Date: 2014-10-28
Classification: G01R,H02H

Abstract:
1. An electrical circuit with fault detection, the electrical circuit comprising: an excitation voltage connected via a first circuit path to an output; a switching device having a control terminal and first and second controlled terminals, the controlled terminals connected in the first circuit path, wherein a control signal provided to the control terminal selectively controls supply of the excitation voltage to the output; a controller for providing the control signal to the control terminal of the switching device at a first frequency; a comparator connected to monitor a switch voltage at the first controlled terminal of the switching device and generate a feedback signal based on a comparison of the monitored switch voltage to a threshold voltage; wherein the controller monitors a second frequency associated with the feedback signal and detects a fault condition based on a comparison of the first frequency to the second frequency; and wherein the electrical circuit is an amplifier circuit having at least one inductive component and at least one capacitive component, wherein a capacitive open-circuit fault condition is detected when the monitored second frequency is greater than the first frequency.