what size resistor?

[tigger69]

just a quickie,what size resistor do i need in line to drop the fan voltage to 7v?,without doing the yellow+/red- thing?.i dont really want or have room for a controller.
thanks guys

[Yin]

well it might be a 5v resistor.......
12v - 5v = 7v
im not a totally sure thats what their measured in but if you ask whereever your buying it from they should help

[mikechinym]

if i am not mistaken,
volt=ohm x ampere...
to reduce the voltage,it must know both the resistor and your fan voltage resistance...

[Yin]

ahh yeh thats right
v/ir
v = voltage (volts)
i = current (amps)
r = resistance (ohms)
Im pretty sure if you look on your psu
it will tell you the amps on your 12volt rail. normally its about 20amps i think, but it varies from psu to psu.
im a physic student but im pretty sure thats right

[ferynov]

Volt = i (ampere) / R (resistor)
then

7 = 5 Ampere (approx) / R

7 / 5 = R R=1.4 Ohm ... check the ring colour ..or ask mr.google