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| Thread ID: 70098 | 2006-06-22 03:44:00 | power for external HDD | Fergie (6508) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 465151 | 2006-06-22 03:44:00 | hey, i'm thinking about getting an external HDD, i was planning on just getting a 3.5" 250gb internal one and putting it into a case. but then i noticed you need an AC power adapter for them, is it possible to have an external HDD without using an AC adapter? Like can i get the power from USB. if so, how do i go about doing this? Cheers |
Fergie (6508) | ||
| 465152 | 2006-06-22 03:50:00 | If it comes with an external power brick it needs more power than you can get from a USB port. That's 500 mA maximum, at 5V ... 2.5W. Many laptops, and unpowered USB hubs, can't provide even that, even though USB is a standard. :( | Graham L (2) | ||
| 465153 | 2006-06-22 04:50:00 | If you get a 2.5" external hard drive, it shouldn't need a additional power source. I have a 80Gb one and never had problems regarding power with it. The cord actually comes with 2 usb plugs at one end in case you need more power, but have never had to use it. The trade off is although it does not require external power, you are limited in the size of the hard drive. 3.5" drives are up to 500Gb and growing , but I havent found any of the smaller 2.5 drives anywhere near that size yet. |
Nyuuji (5460) | ||
| 465154 | 2006-06-22 05:23:00 | The biggest 2.5" drive I have heard of is 160GB. | pcuser42 (130) | ||
| 465155 | 2006-06-22 05:41:00 | It depends on the drive. The voltage and current required by the drive are the major things to look at. If it needs 12V, USB can't do that. If it needs more than 500 mA at 5V USB can't do it. Using two USB connection is a butcher's approach. And it might not work on some laptops anyway. If the case is sold separately, and comes with a power brick, you might be able to wire it internally so the USB provides 5V to a suitable drive as well as the control circuit. But unless you are skilled, and have the tools, I can't recommend you to try to modify a SMD circuit. |
Graham L (2) | ||
| 465156 | 2006-06-22 06:53:00 | I recently bought a case and a 3.5" 160 GB HDD. The case came with it's own power brick, which supplies both 12v and 5v. I also have a 2.5" case and drive, which requires either a power adapter (5v) or 2 x USB connections. I use an external 5v adapter, it can occasionally bring my desktop system to it's knees otherwise. But the laptop copes. I am aware of very expensive motherboard failures arising from using a single USB port for a hard drive power, as there is an SMD fuse on the motherboard in some models that can be very expensive to locate and fix. I would be reading the label on the HDD to see if it needs more than 500 mA (0.5 amp) before using a single socket. |
godfather (25) | ||
| 465157 | 2006-06-22 07:39:00 | ok, sweet as, i'll just go for the safer/cheaper option with a 3.5". just means i won't be able to use it all the time with the laptop - but that'll be sweet! Thanks guys |
Fergie (6508) | ||
| 465158 | 2006-06-22 07:46:00 | I have a Seagate 200GB internal in an external enclosure with a power pack, it works good, altough it is slightly annoyinh having to take the power cords etc. when you take it somewhere, but oh well... | Prescott (11) | ||
| 465159 | 2006-06-22 08:40:00 | I have never had a failure with my one, which have been using for about 8 months. Mate has two of them (60Gb & 80Gb) and he hasent had any trouble either. All run of just one usb port each and have been plugged into numerous pc's. Mind you, I sourced these cases from Akihabara in Japan, not here in NZ. Oldest one is nearly 2 yrs now and still going strong, like I would expect. Hard drives were also from there, come to think of it. Purchased seperately though. |
Nyuuji (5460) | ||
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