computer power supply

[andrew2022]

i have a 300w ATX power supply powering my computer but i think i shud get a second supply because of the amount of drives i have connected. i have 2 cd drives, 4 hard drives, floppy drive, 3 pci card nd a graphix card aswell as loads of usb stuff. hgow do i connect anotha supply 2 power my hard drives etc nd have it switch on/off at the same time as the main supply?

thanx

 

[daviddoria]

**broken link removed**

enjoy!

i once had 3 power supplies going ... it was cool although that was a long time ago ... so if you have questions i'm not sure if i'll be able to help too much... give it a shot though

 

[andrew2022]

thanx. al b tryin that once i find a spare ATX power supply (pity i took 2 apart last week...)

 

[IRQ57]

2nd power supply

Andrew,
You may use a second PS, dedicated to the drives, feeding them with +5v and +12v,and only sharing common 0V (the black wires in the middle of the connectors) or logic ground.

The original PS (OPS) will feed only the processor board and its directly attached cards.

It is possible that the original PS have an outlet for AC accesories, if so, connect the 2nd PS to this outlet. If not, you may use a solid state relay for 2A at 220vac or 4 A for a 110vac supply. See them I.E. at:
https://www.fcl.fujitsu.com/en/products/relay/catalog/solid_1.html

This relay will be driven by a 5v line from the OPS, optically isolated from the AC supply, and taking only a few mA.

Regards

 

[pike]

dont go and add a second power supply to your computer, just go out and get a new one rated at 550 watts! This is just about over kill for any computer.

 

[andrew2022]

dont go and add a second power supply to your computer, just go out and get a new one rated at 550 watts! This is just about over kill for any computer.

i did... just neeed summit until i cud get 1

 

[ab0tj]

Actually, I've ran more than that off a 350w PSU before (8 raid disks). If you aren't having crashing or spontaneous shutdowns, I'd just stick with the 300w.

 

[andrew2022]

i leave all my usb stuff plugged in most of the time so they take more power, the air from the back was also gettin hotter than normal at times. av got a new power supply now anyway

 

[Nigel Goodwin]

i leave all my usb stuff plugged in most of the time so they take more power, the air from the back was also gettin hotter than normal at times. av got a new power supply now anyway

A USB port can only supply a small limited amount of current, if you add a USB expander they normally come with an external PSU - the one I have includes a large TO3 regulator inside!. So any USB items won't be taking much from your computer.

 

[andrew2022]

i leave all my usb stuff plugged in most of the time so they take more power, the air from the back was also gettin hotter than normal at times. av got a new power supply now anyway

A USB port can only supply a small limited amount of current, if you add a USB expander they normally come with an external PSU - the one I have includes a large TO3 regulator inside!. So any USB items won't be taking much from your computer.

all my usb are bus powered, using the computers power supply. i also have 3 4 port hubs

 

[pike]

just monitor you computers 5v and 12v rail. If you setup is drawing more current than the PSU can handle you should notice a slight voltage drop in the supply rails.