Posted on Aug 15, 2012

In this application, the ICM7249 is configured as an hours-in-use meter and shows how many whole hours of line voltage have been applied. The 20-MD resistor and high-pass filtering allow ac line activation of the SIS input. This configuration, which is powered by a 3-V lithium cell, will operate continuously for 21/z years.

Click here to download the full size of the above Circuit.

Without the display, which only needs to be connected when a reading is required, the span of operation is extended to 10 years.

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