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

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More  Indicator Circuits

4 LINE TELEPHONE LINE STATUS INDICATOR
 

Many home businesses use multiple phone lines. This circuit gives you a visual indication when a line is in operation. The two AA battery cells should provide enough power for about one year of operation.

Click on Circuit Below to view PDF of Schematic


4 Line Phone Statue Indicator , Circuit designed by David A. Johnson, P.E.

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