DN Staff

October 10, 2005

2 Min Read
Kanceruk the Magnificent Strikes Again

As an occasional installer of alarm systems, David covered a lot of ground testing the integrity of the four-conductor cables commonly used as wiring. Each wire has four conductors and must be checked for shorts and opens. To cut down on all of the back and forth, he built a simple voltage divider that sends a different voltage down three of the wires with respect to the fourth one-requiring only a single trip to the panel for each wire. Low resistor values ensure the 9V battery isn't killed if the wires are shorted.

Nifty 4-Wire Cable Tester Parts List

Amt

Part Description

Allied Part #

1

Vector Board #8015-1

977-1256

1

3M Single Row Female Socket Strip

618-5162

1

9V Battery Holder

839-1294

1

9V Battery

736-3616

1

Miniature Switch

870-8600

1

5.62K 1/4W 1% Resistor

832-6460

3

1.0K 1/4S 1% Resistor

832-7950

Download Parts List
Download Construction and Usage Details
Download Schematic

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