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Last Updated on: Tuesday, June 01, 2021 03:06 PM

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 Battery Testers   Constant Current / Current Sink  
Resistance Meters



UL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0.1 ohms.  This resistance must be tested with actual line current in excess or 10 Amps.  The circuit shown uses a couple of LEDs to indicate if in fact the resistance is less than 0.1 ohms.  It uses a modified transformer to produce a 2.5vac output with at least 10 Amps of supply current.

Click on Circuit Below to view PDF of Schematic

UL Ground Wire Resistance Tester designed

 by Dave Johnson, P.E. (Apr 28, 2001)

More   Battery Testers  
Constant Current / Current Sink  
Resistance Meters


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