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Safety Alarm Clock

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Step 6: Unplugging

The clock still has a weak point. When you unplug it, the alarm dies... I wanted a way to remedy this situation without resorting to dangerously fixing the plug in the wall...

Now this clock has a back up battery which preserves the clock settings when it is unplugged. I broke out my multimeter to measure the current coming from the battery when the clock is plugged in and unplugged.

A small 0.3mA current when plugged in, and a large 2.3mA current when unplugged. I wonder if i could use that change in current to switch another componant?


 
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