Go Back   Steve's Digicams Forums > Digital Cameras (Point and Shoot) > Sanyo

Reply
 
Thread Tools Search this Thread
Old Mar 8, 2008, 8:44 AM   #1
vip
Junior Member
 
Join Date: Mar 2008
Posts: 6
Default

Well subject says all.

I've bought an Iomega 160Gb 2.5 external disk, and I was somehow expecting the dock could provide enough power to get the disk working without external power, but unfortunately it doesn't. The LED in the disk lits, indicating it somehow gets power, but both the disk does not spin-up and in parallel the camera warns the disk does not respond.
Powering the disk from external source (in my case thru the aux USB port in the Y-cable the disk brings) works as expected. This is really a nice feature!

Question is; has anyone used any external 2.5" that can work without needing an external power supply? (to avoid weight and devices to carry while on travel)

I'm on time to return the Iomega and buy another similar one if known to be less power hungry.

Regards
vip is offline   Reply With Quote
Sponsored Links
Old Mar 8, 2008, 11:06 AM   #2
Senior Member
 
Rev2010's Avatar
 
Join Date: Feb 2008
Posts: 377
Default

No, the manually clearly states a hard disk will need to have it's own power. I can use USB flash memory sticks and that gets powered but that's just a memory stick at only 2gb's. I have a Memorex Ultra 80 gig hard drive and that does require a power source. I simply use a blackberry USB charger which has a standard USB cable that goes into the adapter. I take it out and put in the USB power cable that came with my drive and it's great. Just traveled to Cancun and it worked perfectly.

USB is a standard 5v supply so you can simply pick up one if your drive came with a USB to power cable.

Rev.
Rev2010 is offline   Reply With Quote
Old Mar 10, 2008, 10:17 AM   #3
Junior Member
 
Join Date: Feb 2008
Posts: 16
Default

Hey Rev,
Again it is you who has the answers! So let me get this straight - you have a blackberry charger that plugs into the wall and has a USB port that usually is attached to another cord that goes into your blackberry. But you remove the USB to blackberry cord and replace it with the USB power plug for your HDD that then allows you to save your Xacti footage? Correct? lol, i think i need a diagram!

So i wonder if my mobile phone charger will work if it puts out 5v? Whats the amp output for USB?

If i can get this going i will be very :?:G
Albot is offline   Reply With Quote
Old Mar 10, 2008, 4:51 PM   #4
Senior Member
 
Rev2010's Avatar
 
Join Date: Feb 2008
Posts: 377
Default

Yep, it's just as you described. Here's a link to see what it basically looks like:

http://www.cablestogo.com/product.as...&sku=22328

As for the amp I think it's 1Amp but I'm not too sure.



Rev.
Rev2010 is offline   Reply With Quote
Old Mar 10, 2008, 7:27 PM   #5
Junior Member
 
Join Date: Feb 2008
Posts: 16
Default

Aha! That's just what i thought you could do

However I got myself into a little bind about the mA output as i was not sure what was required to power a 2.5" external HDD. Apparently the USB socket on my laptop has a max output of 500mA, which is adequte for powering the HDD. But I wasnt sure what would happen in i put 700mA or even 1A through an electrical device that couldnt handle it :| ?

I found an adapter for AU$26 that puts out 700mA and one that puts out 300mA for AU$1, so lol the dilema i have is that will 300mA be enough!?! But atleast i know that your HDD didnt fry when putting 1A through it. Maybe i am being naive about electric current and that mAmpage doesnt matter too much.

Oh well, i am planning to get the $1 300mA and will be very happy if it does the job.

One last thing, the HDD has to be FAT32 to use the library function, right?

Thanks for all the info!
Albot is offline   Reply With Quote
Old Mar 10, 2008, 10:44 PM   #6
Senior Member
 
Rev2010's Avatar
 
Join Date: Feb 2008
Posts: 377
Default

Don't worry too much about the milliamps. I've personally never had a problem with mismatching milliamps so long as you have the volts correct. Actually, if you look at rechargeable AA batteries from the same manufacturer you will find many variances. I have aDuracell kit and recently went to buy extra rechargeable AAbatteries and was suprised there were so many different millamp versions. Some were 1200mA, some 2350mA, and some 2500mA. They all work in any device that takes AA batteries but the higher mA versions touted longer lasting performance. So, as long you have the USB standard of 5v I thinkyou should be ok. But, I'm an IT Tech not an electrician so I'm merely speaking from my personal experience.



Rev.
Rev2010 is offline   Reply With Quote
Old Mar 11, 2008, 2:58 AM   #7
Member
 
ddchesser's Avatar
 
Join Date: Dec 2007
Posts: 62
Default

Rev2010 is right!

I'm an electrical engineer . There are to things for supplying the external 2.5" HDD:

1. The voltage of the supply has to be 5V (Volts).

2. How much current (measured in mA) is necessarey depends on the drive, not on the power supply! Normally about 700mA.


Most 2.5" external HDD have therefore two USB-connectors, because one USB Connection (on the PC) delivers max. 500mA. Some HDD also has an extra power connector for 5V.


If your supply is to week: for example 500mA and the drive needs 700mA. Then the drive wouldn't not work. The Voltage brakes down. The overloading could also damage the supply.

To play in safe: Try to find any supply, that delivers 5V/1000mA (1A) with a suitable connection.
ddchesser is offline   Reply With Quote
Old Mar 11, 2008, 3:15 AM   #8
Junior Member
 
Join Date: Feb 2008
Posts: 16
Default

Thanks ddchesser, its always nice to have an electrical engineer around for such discussions. :G Let me know if you need any info on Biological Science.

My lacie 160gb 2.5" external HDD runs fine using only the max 500mA from the USB connection and now we have acertained that is ok to put 1A though it. BUT, being a spendthrift, i have just bought (for AU$1 including postage) a 5V charger with a max of 300mA and i am wondering if that will power my USB HDD. I guess time will tell. If that doesnt work i shall have to fork out more for the 700mA one.

Oh, one more thing. I have yet to whinge about the docking station not supplying enough power in the first place :evil: grrr ok now i am over it.

Thanks for all the info, may the contents of your brain continue to smoother this forum.

Albot
Albot is offline   Reply With Quote
Old Mar 11, 2008, 3:30 AM   #9
Member
 
ddchesser's Avatar
 
Join Date: Dec 2007
Posts: 62
Default

Fine, you are happy again!

Only to clarify: The current through the HDD isn't 1A. The HDD only takes what it needs (for example 500 or 700mA) the supply has to be at least that strong.








ddchesser is offline   Reply With Quote
Old Mar 11, 2008, 3:54 AM   #10
Junior Member
 
Join Date: Feb 2008
Posts: 16
Default

OIC.

I read last night a useful plumbing analogy to explain volatage, current etc. The pressure of the water into a pipe is the voltage, the flow rate is the current and is porportional to the size of the pipe, which is the resistance. So the smaller the pipe (higher the resistance) the higher the current (Amps). Very interesting. It helped me to understand how an identical voltage can produce varying amps - just like putting your thumb over the end of a hose, rather than lettting it dribble out.

So out of curiosity, is there anyway (without using specialised instruments) to determine how much ampage the HDD requires?

Albot
Albot is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 8:07 AM.