Ground fault circuit interrupter with enhanced radio frequency interference suppression

• US 20060018061A1
• Filed: 04/01/2005
• Published: 01/26/2006
• Est. Priority Date: 04/12/2004
• Status: Active Grant

• Current Assignee: Leviton Manufacturing Company Incorporated
• Original Assignee: Leviton Manufacturing Company Incorporated
• Inventors: Chan, David Y., Shafir, Eugene, Libretto, John
• Granted Patent: US 7,375,935 B2
• Time in Patent Office: Days
• US Class Current: 361/42
• CPC Class Codes: H02H 3/33 using summation current transformers H02H3/347 takes precedence
• CPC Class Codes: H02H 9/005 avoiding undesired transient conditions

Abstract

A ground fault circuit interrupter device having a feedthrough capacitor for substantially reducing interference from radio frequency signals such as those emitted from cell phones. The ground fault circuit interrupter device includes a printed circuit board having a system ground terminal and a detection terminal for receiving a fault detection signal. A chip is provided having a ground pin connected to the system ground terminal and an input pin for receiving the fault detection signal. The feedthrough capacitor has a through conductor connected between the input pin and the detection terminal and a capacitor coupled between the through conductor and the system ground terminal.

Claims

1. A ground fault circuit interrupter device comprising:

a printed circuit board having a system ground terminal and a detection terminal for receiving a fault detection signal;

a chip having a ground pin connected to the system ground terminal and an input pin for receiving the fault detection signal; and

a feedthrough capacitor having a through conductor connected between the input pin and the detection terminal and a capacitor coupled between the through conductor and the system ground terminal.

2. The ground fault circuit interrupter device of claim 1 wherein the input pin is connected to an input of an operational amplifier.

3. The ground fault circuit interrupter device of claim 1 wherein the feedthrough capacitor has attenuation characteristics that increase at approximately 20 decibels per decade from its cutoff frequency.

4. The ground fault circuit interrupter device of claim 1 wherein the feedthrough capacitor has a cutoff frequency selected from a band of frequencies between 1 to 300,000 megahertz.

5. The ground fault circuit interrupter device of claim 1 wherein the feedthrough capacitor has a cutoff frequency selected from a range of frequencies in the 850 megahertz band for cell phone service.

6. The ground fault circuit interrupter device of claim 1 wherein the feedthrough capacitor has a cutoff frequency selected from a range of frequencies in the 1850 megahertz band for cell phone service.