Patent ID: 8873211
Filing Date: 2014-10-28
Classification: G05F,H02H,H02J,H03K

Abstract:
1. A protection circuit for AC loads, the circuit comprising: a controller monitoring one or more characteristics of an AC signal on an electrical line in communication with the AC load, wherein the controller is operable to generate a pulse width modulated signal based on the one or more characteristics of the AC signal; and a switching stage connected to the electrical line carrying the AC signal and controlled by the controller, wherein the switching stage attenuates the AC signal using the pulse width modulated signal from the controller; one or more electrical isolation stages, the one or more electrical isolation stages operable to isolate the controller from at least the switching stage and a signal conditioning stage that provides a signal indicative of the one or more characteristics of the AC signal, and wherein the controller is electrically isolated from the AC signal such that the controller electrically floats relative to the AC signal.