www.fairchildsemi.com

REV. 1.0.5 12/7/04

Features

• No potentiomenter required

• Direct interface to SCR

• Supply voltage derived from AC line – 26V shunt

• Adjustable sensitivity

Description

The RV4145A is a low power controller for AC outlet

ground fault interrupters. These devices detect hazardous

grounding conditions, such as equipment (connected to

opposite phases of the AC line) in contact with a pool of

water and open circuits the line before a harmful or lethal

shock occurs.

Contained internally are a 26V zener shunt regulator, an op

amp, and an SCR driver. WIth the addition of two sense

transformers, a bridge rectifier, an SCR, a relay, and a few

additional components, the RV4145A will detect and protect

against both hot wire to ground and neutral wire to ground

faults. The simple layout and conventional design ensure

ease of application and long-term reliability.

Block Diagram

R2

10K

R1

10K

(+26V)

SCR Trigger

+Input

Ground

R3

4.7K

65-4145A-01

RV4145A

Op Amp Output

6.5V

6.5V

6.5V

6.5V

(+13V)

RV4145A

Low Power Ground Fault Interrupter

• Grounded neutral fault detection

• Meets U.L. 943 standards

• 450µA quiescent current

• Ideal for 120V or 220V systems