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| Thread ID: 42426 | 2004-02-10 20:06:00 | Is This Going To Over Load My USB Port? | Gods-Hitman (1419) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 214387 | 2004-02-10 20:06:00 | Hi, I made this to cool my laptop sal.neoburn.net and as you can see this was made for a desktop but iv made it usb, is this going to over load my laptop? The fan's are 12V DC Thank You |
Gods-Hitman (1419) | ||
| 214388 | 2004-02-10 20:31:00 | Hi GH TTBOMK, USB sockets can only supply 5 volts, so unfortunately your cooling system will probably need an external power source. Cheers Billy 8-{) |
Billy T (70) | ||
| 214389 | 2004-02-10 20:38:00 | OK, I can confirm that now, 5 volts @ 500 mA so you will need to re-think your cooling needs. Is there any particular reason why you think you need more cooling than the manufacturer has already supplied? Cheers Billy 8-{) |
Billy T (70) | ||
| 214390 | 2004-02-11 03:30:00 | Why? becuse its a laptop that I game on and its just got 1 small fan over CPU (Ram gets hot very hot!) and I pluged in my home made fan thingy and it worked .. but if you put your finger in it it stops and you have to spin it to start it but still its something | Gods-Hitman (1419) | ||
| 214391 | 2004-02-11 05:03:00 | Hiya, I was actually thinking of doing exactly the same thing, you can get fans from jaycar i believe that are 60mm 5V and 250mA or something. In theory it would be possible or though it wouldn't exactly be a high power fan... just a breeze. You'd need a couple of resistors as well to get current down... It would also be possible to use a 12V fan but it obviously won't go as fast at 5V. - David |
DangerousDave (697) | ||
| 214392 | 2004-02-11 20:55:00 | Just a thought, what with battery life and all that I guess you are not gaming on the run, and if you were the added drain on the batteries for your extra cooling fans would make for very short games. Why not pick up a cheap 12 volt power supply and power your fans from that? DSE have a 500 mA multi-voltage supply for under $30, but you can pick up old power adapters for $5-$10 in second hand shops everywhere. I'd go for something with 750 mA to 1 amp rating if I could find it though, because cheap supplies drop their output voltage quite severely when near their maximum current rating. I wouldn't do the 2 x 5 volt fans trick as they would need to be throttled back to around 350 mA to relieve the strain on your USB port and your battery life. I am not sure if that would produce a linear reduction in airflow or not, but I suspect the loss would be greater than linear as fans need to operate at design-speed RPM for maximum efficiency. It follows then that lower speed doesn't simply translate to a proportional loss of airflow. Cheers Billy 8-{) |
Billy T (70) | ||
| 214393 | 2004-02-12 03:38:00 | Im looking on DSE, and yea I think im going for a PSU Thanks For The Help PS:Yea I don't game on the run *try playing computer strike on a laptop mouse...* |
Gods-Hitman (1419) | ||
| 214394 | 2004-02-12 04:48:00 | I don't think 700 mA of fans would "overload" the USB port. The USB 5V is fed from the main 5V supply, possibly though a fuse (but fuses cost money :D). The main 5V supply has some grunt. The 500 mA limit is there because people do silly things. If you pulled 20A through a USB cable smoke would come from the cable. And you might shut down the PSU. USB devices tell the controller what their current requirement is. (That's part of the information sent with the device ID). Software probably keeps track of the total drain on a port, and might refuse to turn on any device added which would exceed the limit. The fans are not a USB device. They won't tell the controller. :D |
Graham L (2) | ||
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