US 9,331,469 B2 · Ground fault circuit interrupter and method

Abstract

A method and circuit for determining a circuit element parameter in a ground fault circuit interrupter circuit. An electrical signal provided to a first node is used to generate another electrical signal at a second node. The electrical signal at the second node is multiplexed with a modulation signal to generate a modulated signal that is then filtered and converted into a digital representation of a portion of the circuit element parameter. The electrical signal at the second node is multiplexed with the modulation signal after it has been phase shifted to produce a modulated signal that is filter and converted into a digital representation of another portion of the circuit element parameter. In another aspect, a slope based solenoid self-test method is used for self-testing in a GFCI circuit. Alternatively, a method for determining a wiring fault is provided using a digital filter.

Claims8

Dependent claims

A ground fault circuit interrupter module, comprising:

an offset correction circuit having first and second inputs and at least one output, the offset correction circuit including at least one of a chopper amplifier or an auto-zeroing circuit;
a switch having first, second, and third conduction terminals and a control terminal, the first conduction terminal coupled to the first input of the offset correction circuit;
a biasing module having an input and an output, the output of the biasing module coupled to the second conduction terminal of the switch;
and
a signal generator having an output coupled to the third conduction terminal of the switch.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application

13/829,366Filed 14 Mar 2013 · continuation in part

Priority

2 Oct 2009

Published

US 2013/0215537 A122 Aug 2013

Granted

3 May 2016

Term ends

Not estimatedThe source records don’t support an estimate.

Classification14 codes

G01R 31/52
Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections: testing…
G01R 27/18
Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line: measuring resistance to…
H02H 3/162
Responsive to fault current to earth, frame or mass: for AC systems
H02H 3/33
Involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go…:…

Family

Application12/572,870Parent of this continuation-in-part · filed 2 Oct 2009

US 8,390,297 B2Parent of this continuation-in-part · filed 5 Mar 2013

US 2013/0215537 A1Pre-grant publication · published 22 Aug 2013

US 2011/0080177 A1Published application

US 9,331,469 B2This patent

From the US filing history. Foreign family members aren’t listed.

Ground fault circuit interrupter and method

Life of this patent

Ground fault circuit interrupter and method

Life of this patent

Abstract

Claims8