questions about the 7volt mod for fanbus

[hbidad]

Well, I originaly wired my second 230 watt PSU up that is dedicated to my fans.. I originaly had the baybus setup 12v-off-5v with a 3 position switch (up=on middle=off down=on)

Well, the noise is starting to get to me running the fans at 12volt and 5v wasnt cutting it no more... So I decided to go 12v-off-7volt.
but my problem is it kicks out the PSU as soon as I flip the switch to get 7 volt.

Does it take alot of power to do the 7volt mod? I thought I might have wired up something wrong... So I twisted the fans leads together and put the negative side for the fans into the 5v line of the PSU and put the positive side of the fan leads in the 12v line. It then kicked out again.

how much watts should I get to power 5 fans doing the 7 volt mod?

BTW when I checked my fanbus block....I indeed had 7 volt when checked with a volt meter

[Wiggo]

The 7v mod is basically using the +5v as the ground for the +12v which the difference gives 7v.
Take a look at these wiring diagrams here http://www.fanbus.com/thelab/Schemat...schematics.htm :smokin:
<center>:cheers:</center>

[hbidad]

Wiggo, I put a constant 12 volt to the positive side of the fans (straight from the PSU..no switches)....then I wired the switches to change the ground side of the fans from 5volt and ground....


this is the proper way, right?

I can run all fans encluding 2 Cold cathode lights with the fans running at 12volt..

but when I put 1 fan on 7 volt with a CC light (at 12v on same PSU)....the CC gets dim.. add another fan and it kicks out the PSU.... I can get 3 fans going at the 7volt setting if the fans are already spinning... Like if I turn them on 12 volt first....then flip the switch to the 7volt

hmmm.... anybody have alot of fans running the 7 volt mod trick? What wattage are you using?

[daedalus]

There is a possibility that it may she shorting out somewhere....are all your wires properly insulated :confused:

[hbidad]

yep, I checked everything with an Ohm meter.... no shorts

[daedalus]

Well, you've got me stumped....How many fans are you trying to run of it anyway ?

[Wiggo]

You'd think that 5 fans would be ok. :?:

[daedalus]

Yeah i'd say so...:confused: