HomeProfilingPhotoPrintArticlesLinuxAmiga

Introduction

Wacom Bamboo Fun Small

EPIA Mini-ITX Motherboard

EPIA CIR Header

Reducing Fan Speeds

Fan Voltage Calculator


Reduce  volts,  amps, to  volts.  

Original fan voltage: 12V

Original fan current: 0.25A

    V=IR (Ohm's Law), so 12 = 0.25R   =>   R = 12 / 0.25   =   48

Fan resistance: 48 Ohms

Target voltage: 7V

    V=IR (Ohm's Law), so 7 = 48I   =>   I = 7 / 48   =  0.146

Target current: 0.146A

Voltage drop across resistor: 12V - 7V  =  5V

    V=IR (Ohm's Law), so 5 = 0.146R    =>    R = 5 / 0.146    =  34.286

Target resistance:  34.286 Ohms

Power dissipated by resistor:  5V * 0.146A  =  0.729W

Back to the fan speed page...