Computer voltage monitor 2011-06-16

This is an illustrated tutorial on building a voltage monitor for fan control circuits - rheostats, linear regulators like the LM317/350, and some PWM circuits. It requires a single chip, and can drive 10 LEDs with even divisions from 0V to 12V.


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The LM3914 is a chip made specifically for driving LEDs based on voltage. A few notes about the circuit above:

• Pin 9 (the Mode pin) sets whether dots or bars are used. We've tied it to +12V so it'll be on...

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