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Switching Power of hard drives ON and Off

V

Vlad

Jan 1, 1970
0
Switching Power of hard drives ON and Off
I have a few hard drives that are rarely used and in order to save the
drives I am thinking of switching the +12 volts OFF when the drives
are not required.
I believe the +12 is the voltage used for the motor. If the motor
doesn't run the drive will not be recognized by the BIOS.
I realize the operation of those switches should only be done when the
computer is off . I will be using toggle switches with a locking
lever.
Will this create any unforeseen problems?
Thanks for the help
Vlad
 
S

Steve

Jan 1, 1970
0
Vlad said:
Switching Power of hard drives ON and Off
I have a few hard drives that are rarely used and in order to save the
drives I am thinking of switching the +12 volts OFF when the drives
are not required.
I believe the +12 is the voltage used for the motor. If the motor
doesn't run the drive will not be recognized by the BIOS.
I realize the operation of those switches should only be done when the
computer is off . I will be using toggle switches with a locking
lever.
Will this create any unforeseen problems?
Thanks for the help
Vlad

I question the wisdom of switching off only 12 v, and I presume
leaving +5 v, if I understand what you are proposing.

May I recommend this $7.95 solution?
http://www.geeks.com/details.asp?invtid=GN210-BLK&cat=HDD

Or I am sure you can find better quality ones from many sources.

Alternatively, look at a USB external case for your IDE drive.
Here is one for Firewire and/or USB. No reboot and "BIOS screwing"
required.

http://www.geeks.com/details.asp?invtid=DLX-185&cat=HDD

Thanks, Steve
 
V

Vlad

Jan 1, 1970
0
I question the wisdom of switching off only 12 v, and I presume
leaving +5 v, if I understand what you are proposing.

May I recommend this $7.95 solution?
http://www.geeks.com/details.asp?invtid=GN210-BLK&cat=HDD

Or I am sure you can find better quality ones from many sources.

Alternatively, look at a USB external case for your IDE drive.
Here is one for Firewire and/or USB. No reboot and "BIOS screwing"
required.

http://www.geeks.com/details.asp?invtid=DLX-185&cat=HDD

Thanks, Steve
I am already using two USB drives and one of the drives that I want to
stop is a serial and they don't work on the available boxes.

Thanks

Vlad
 
S

Sam Goldwasser

Jan 1, 1970
0
Steve said:
I question the wisdom of switching off only 12 v, and I presume
leaving +5 v, if I understand what you are proposing.

I too. In general, unless the equipment specifically states that it
is safe to switch off some of the supply voltages, I wouldn't recommend
it. Not only might the equipment be damaged (though probably unlikely),
but there could be peculiar behavior of anything attached to it (in this
case, the computer).

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.
 
S

Steve

Jan 1, 1970
0
Vlad said:
I am already using two USB drives and one of the drives that I want to
stop is a serial and they don't work on the available boxes.

Thanks

Vlad

Vlad,

Well, I guess I didn't have all the facts??

Here is a USB to SATA case.
http://www.cooldrives.com/nasadrenwiou.html
Add a USB hub if you need to. Google helped find it.

Or use the SATA interface directly, if the rest of your system has an
external SATA connection. (And if it does, then there are
cheaper SATA only external cases. Google for some.)

Still confused as to why, then, the $7.95 solution
won't work for one drive, which, I assume, perhaps incorrectly, is
IDE?

Please let "suggest" again that the 12 v switching isn't
recommended. But maybe it will work. Prove me wrong. Report back to
the group your results. Be sure to mention what drives you are
talking about, exactly, since maybe what works for brand X, model Y,
won't work for brand Z, model A. We'll all learn, which is the idea here.
If it is a viable and universal solution, someone somewhere would
be doing it commercially, which I'm quite unaware of.

Good Luck and Thanks, Steve
 
I

Ivor Floppy

Jan 1, 1970
0
Vlad said:
Switching Power of hard drives ON and Off
I have a few hard drives that are rarely used and in order to save the
drives I am thinking of switching the +12 volts OFF when the drives
are not required.
I believe the +12 is the voltage used for the motor.

Believe what you want - simply switching the 12V supply is asking for
trouble. If your going to switch, you need both the +5 and the +12 supplies
or you'll end up with a zapped drive.
If the motor
doesn't run the drive will not be recognized by the BIOS.

But the drive will still be connected; if the +5 is still active so would
90% of the electronics (if drives were to work as simply as you suggest), so
it would be recognized in the BIOS.
Will this create any unforeseen problems?

Lots.
 
M

Mark

Jan 1, 1970
0
so what happens when windows puts the drive in power down mode...

i think the key is you want to make sure the heads are parked before
you spin down the disc, but you said you would only operate the switch
when the computer is OFF.

I say try it.

Mark
 
I

Ivor Floppy

Jan 1, 1970
0
Mark said:
so what happens when windows puts the drive in power down mode...

Have a guess. I'll give you a big clue - Windows can't somehow disconnect
the power leads to the drive.....
 
S

Sam Goldwasser

Jan 1, 1970
0
Have a guess. I'll give you a big clue - Windows can't somehow disconnect
the power leads to the drive.....

So what? It's not the electronics that wear out. That may be good enough
if you're really worried about the life of the drive.

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.
 
J

James Sweet

Jan 1, 1970
0
Vlad said:
Switching Power of hard drives ON and Off
I have a few hard drives that are rarely used and in order to save the
drives I am thinking of switching the +12 volts OFF when the drives
are not required.
I believe the +12 is the voltage used for the motor. If the motor
doesn't run the drive will not be recognized by the BIOS.
I realize the operation of those switches should only be done when the
computer is off . I will be using toggle switches with a locking
lever.
Will this create any unforeseen problems?
Thanks for the help
Vlad

Why don't you just have the software spin the drive down after a period of
inactivity?
 
F

Franc Zabkar

Jan 1, 1970
0
Believe what you want - simply switching the 12V supply is asking for
trouble. If your going to switch, you need both the +5 and the +12 supplies
or you'll end up with a zapped drive.

If you disconnect the +5V supply, you may then have an improperly
terminated IDE cable. I suspect this may cause problems with
reflections.
But the drive will still be connected; if the +5 is still active so would
90% of the electronics (if drives were to work as simply as you suggest), so
it would be recognized in the BIOS.

I know some drives (eg the old Quantum Fireball) make use of
"discware", so an unreadable platter may cause the HD to be invisible
to the BIOS.

I also seem to recall that a HD is invisible when it fails to spin up
due to stiction.


- Franc Zabkar
 
F

Franc Zabkar

Jan 1, 1970
0
I too. In general, unless the equipment specifically states that it
is safe to switch off some of the supply voltages, I wouldn't recommend
it. Not only might the equipment be damaged (though probably unlikely),
but there could be peculiar behavior of anything attached to it (in this
case, the computer).

I suspect the +12V rail merely powers the mechanical assemblies. A
healthy +5V rail would probably guarantee the drive's sanity, and
would probably be sufficient to ensure that the IDE interface was not
in a "hung" state. Having said that, I wonder if any chip that expects
dual supplies could be damaged by latchup?


- Franc Zabkar
 
V

Vlad

Jan 1, 1970
0
Why don't you just have the software spin the drive down after a period of
inactivity?

YES yes yes James!

That is the best idea but unfortunately Windows XP turns off ALL
the drive/s not only the ones we want.
So if the XP can spin down the drives may be there is a software way
to spin down the ones you want. It should include "serial" and
external drives, if possible.
If such program doesn't exist, it may be created.
There is a need for that. If we stop the drive/s used for a backup,
that in my case is once a week, the drive should last 5 to 7 times
longer.
Ideally it should control the BIOS because the hardest action on the
drive is the starting.

Thanks to all of you
Vlad
 
M

Mark

Jan 1, 1970
0
well it does "disconnet" the drive motor because it parks the heads and
spins it down...

I know this "disconnect" happens within the drive itself and not within
the power supply or the cable.

Disconnecting the 12V probably is about the same.... IF YOU PARK THE
HEADS FIRST!

I suggest you test this on a drive that you don't care about first.


Mark
 
I

Ivor Floppy

Jan 1, 1970
0
Mark said:
well it does "disconnet" the drive motor because it parks the heads and
spins it down...

I know this "disconnect" happens within the drive itself and not within
the power supply or the cable.

Thats quite an important difference. Telling the drive to stop (as Windows
does) means the drive *knows* its not supposed to be running, and goes into
sleep mode waiting to be awoken.
Disconnecting the 12V probably is about the same.... IF YOU PARK THE
HEADS FIRST!

I doubt its anything like the same. The drive is expecting the 12V supply to
be there - under all normal operational circumstances it would be, so
there's no reason for the drive to have any form of protection or safety
checking against such an event. As the drive will be assuming the 12V is
present, it will be constantly trying to get the motor running, putting
who-know-what strain on the motor drive circuitry.
I suggest you test this on a drive that you don't care about first.

... nice get out clause there....:)
 
V

Vlad

Jan 1, 1970
0
YES yes yes James!

That is the best idea but unfortunately Windows XP turns off ALL
the drive/s not only the ones we want.
So if the XP can spin down the drives may be there is a software way
to spin down the ones you want. It should include "serial" and
external drives, if possible.
If such program doesn't exist, it may be created.
There is a need for that. If we stop the drive/s used for a backup,
that in my case is once a week, the drive should last 5 to 7 times
longer.
Ideally it should control the BIOS because the hardest action on the
drive is the starting.

Thanks to all of you
Vlad

I just wonder if we disable a drive on BIOS it stops it from running ?
I don't think so. It only prevents it from being accessed,

Vlad
 
A

Asimov

Jan 1, 1970
0
"Vlad" bravely wrote to "All" (31 Mar 05 15:38:33)
--- on the heady topic of "Re: Switching Power of hard drives ON and Off"

Vl> From: Vlad <[email protected]>
Vl> Xref: aeinews sci.electronics.repair:44617

Vl> I just wonder if we disable a drive on BIOS it stops it from running ?
Vl> I don't think so. It only prevents it from being accessed,

9cm drives for portables are like that and they only startup when the
bios queries them. These are meant to be frugal with battery power.

A*s*i*m*o*v

.... New computer? But I like my vacuum tubes... They keep me warm.
 
V

Vlad

Jan 1, 1970
0
"Vlad" bravely wrote to "All" (31 Mar 05 15:38:33)
--- on the heady topic of "Re: Switching Power of hard drives ON and Off"

Vl> From: Vlad <[email protected]>
Vl> Xref: aeinews sci.electronics.repair:44617

Vl> I just wonder if we disable a drive on BIOS it stops it from running ?
Vl> I don't think so. It only prevents it from being accessed,

9cm drives for portables are like that and they only startup when the
bios queries them. These are meant to be frugal with battery power.

A*s*i*m*o*v

That's interesting. I must try that.
Thanks
Vlad
 
M

Mark D. Zacharias

Jan 1, 1970
0
Vlad said:
Switching Power of hard drives ON and Off
I have a few hard drives that are rarely used and in order to save the
drives I am thinking of switching the +12 volts OFF when the drives
are not required.
I believe the +12 is the voltage used for the motor. If the motor
doesn't run the drive will not be recognized by the BIOS.
I realize the operation of those switches should only be done when the
computer is off . I will be using toggle switches with a locking
lever.
Will this create any unforeseen problems?
Thanks for the help
Vlad

Bad idea. The heads should be parked first. Some operating systems offer the
option of turning off the hard drive(s) after a preset time interval.

Mark Z.
 
A

Asimov

Jan 1, 1970
0
"Mark D. Zacharias" bravely wrote to "All" (02 Apr 05 05:26:33)
--- on the heady topic of "Re: Switching Power of hard drives ON and Off"

MDZ> From: "Mark D. Zacharias" <[email protected]>
MDZ> Xref: aeinews sci.electronics.repair:44760


MDZ> "Vlad said:
Switching Power of hard drives ON and Off
I have a few hard drives that are rarely used and in order to save the
drives I am thinking of switching the +12 volts OFF when the drives
are not required.
I believe the +12 is the voltage used for the motor. If the motor
doesn't run the drive will not be recognized by the BIOS.
I realize the operation of those switches should only be done when the
computer is off . I will be using toggle switches with a locking
lever.
Will this create any unforeseen problems?
Thanks for the help
Vlad

MDZ> Bad idea. The heads should be parked first. Some operating systems
MDZ> offer the option of turning off the hard drive(s) after a preset time
MDZ> interval.

Mark,

Have you forgotten that modern HD's autopark the moment the supply
power goes off. What is a BIG problem is powering off without flushing
the write cache. Windows is a real pig for this and is the reason why
it needs to be shutdown before turning off the power supply. The
lovely lost clusters left all over the HD can make a grown man cry, or
at least tear his hair out.

A*s*i*m*o*v

.... New computer? But I like my vacuum tubes... They keep me warm.
 
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