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

Vlad wrote:

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?inv...10-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

On Wed, 30 Mar 2005 15:10:52 -0600, Steve wrote:

Vlad wrote:

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?inv...10-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

Steve writes:

Vlad wrote:

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.

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.

Vlad wrote:

On Wed, 30 Mar 2005 15:10:52 -0600, Steve wrote:

Vlad wrote:

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?inv...10-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

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

"Vlad" wrote in message
...
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.

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

"Mark" wrote in message
oups.com...

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.....

"Ivor Floppy" writes:

"Mark" wrote in message
oups.com...

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.....

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.

"Vlad" wrote in message
...
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?

On Thu, 31 Mar 2005 01:20:02 GMT, "Ivor Floppy"
put finger to keyboard and composed:


"Vlad" wrote in message
.. .
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 you disconnect the +5V supply, you may then have an improperly
terminated IDE cable. I suspect this may cause problems with
reflections.

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.

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.

Will this create any unforeseen problems?

Lots.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

On 30 Mar 2005 19:23:58 -0500, Sam Goldwasser
put finger to keyboard and composed:

Steve writes:

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).

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
--
Please remove one 's' from my address when replying by email.

On Thu, 31 Mar 2005 03:18:54 GMT, "James Sweet"
wrote:


"Vlad" wrote in message
.. .
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?


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

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

"Mark" wrote in message
oups.com...
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....


Mark

On Thu, 31 Mar 2005 11:06:00 -0500, Vlad wrote:

On Thu, 31 Mar 2005 03:18:54 GMT, "James Sweet"
wrote:


"Vlad" wrote in message
. ..
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?


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

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

Vl From: Vlad
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.

On Thursday, 31 Mar 2005 21:49:06 -500, "Asimov"
wrote:

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

Vl From: Vlad
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


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

"Vlad" wrote in message
...
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.

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

MDZ From: "Mark D. Zacharias"
MDZ Xref: aeinews sci.electronics.repair:44760


MDZ "Vlad" wrote in message
MDZ ...
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.

On Sat, 2 Apr 2005 05:26:33 -0600, "Mark D. Zacharias"
put finger to keyboard and composed:


"Vlad" wrote in message
.. .
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.

The OP understands that "the operation of those [+12V] switches should
only be done when the computer is off".

In any case, if power is removed from the servo, the kinetic energy of
the rotating platters will auto-park the heads.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

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



Every drive on the market has autoparked for at least 15 years now so as you
say that's certainly not an issue. The last drive I had to manually park was
a whopping 20 megabytes and was a 5.25" 2" high drive.

You're certainly right about the write cache though, fortunatly you can turn
this off if you desire, but it does provide a performance boost.

From the discussions we had I conclude that installing a switch that
powers ON and OFF the +5 and the +12 is a very safe way to operate,
provided the switches are only operated when power is OFF.

I have looked at my BIOS and I can't see any indication that will
allowe me to power OFF any of my hard drives.

Let's face it,computers are made as cheap as possible and reliability
is expensive.
A hard drive lasts longer if it isn't running.

Thanks

Vlad

On Sun, 03 Apr 2005 19:10:28 GMT, "James Sweet"
wrote:


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



Every drive on the market has autoparked for at least 15 years now so as you
say that's certainly not an issue. The last drive I had to manually park was
a whopping 20 megabytes and was a 5.25" 2" high drive.

You're certainly right about the write cache though, fortunatly you can turn
this off if you desire, but it does provide a performance boost.

"Vlad" bravely wrote to "All" (03 Apr 05 22:24:29)
--- on the heady topic of " Switching Power of hard drives ON and Off"

This is an anecdote but my 1st year computer hardware teacher also
worked as a researcher for an industrial think-tank and I had to go to
his home once to deliver a late work assignment. While there he showed
me his workbench and to my amazement his pc was a rat's on a table
top. In front of it was a shelf of various harddrives with a switch
under each. When the pc had finished booting he would turn off the
particular HD switch and do whatever work or experiment. When he
needed to save something he would turn the drive back on. The pc was
still ON when he flipped the switch and the drive didn't miss a beat.
It was very eye-opening.


Vl From: Vlad
Vl Xref: aeinews sci.electronics.repair:44897

Vl From the discussions we had I conclude that installing a switch that
Vl powers ON and OFF the +5 and the +12 is a very safe way to operate,
Vl provided the switches are only operated when power is OFF.

Vl I have looked at my BIOS and I can't see any indication that will
Vl allowe me to power OFF any of my hard drives.

Vl Let's face it,computers are made as cheap as possible and reliability
Vl is expensive.
Vl A hard drive lasts longer if it isn't running.

Vl Thanks

Vl Vlad

.... That was a fascinating period of time for electronics

On Monday, 04 Apr 2005 08:46:46 -500, "Asimov"
wrote:

"Vlad" bravely wrote to "All" (03 Apr 05 22:24:29)
--- on the heady topic of " Switching Power of hard drives ON and Off"

This is an anecdote but my 1st year computer hardware teacher also
worked as a researcher for an industrial think-tank and I had to go to
his home once to deliver a late work assignment. While there he showed
me his workbench and to my amazement his pc was a rat's on a table
top. In front of it was a shelf of various harddrives with a switch
under each. When the pc had finished booting he would turn off the
particular HD switch and do whatever work or experiment. When he
needed to save something he would turn the drive back on. The pc was
still ON when he flipped the switch and the drive didn't miss a beat.
It was very eye-opening.


Apparently Microsoft is working on this. It will be available on a new
Windows and is called" Power Manage something" and it will work on the
drives that are compatible with the scheme. They will get to work
after a few updates.
We can do it today with the drives connected to the USB port but as
you know they must be disabled before the power is switch OFF.
Regards

Vlad

Vl From: Vlad
Vl Xref: aeinews sci.electronics.repair:44897

Vl From the discussions we had I conclude that installing a switch that
Vl powers ON and OFF the +5 and the +12 is a very safe way to operate,
Vl provided the switches are only operated when power is OFF.

Vl I have looked at my BIOS and I can't see any indication that will
Vl allowe me to power OFF any of my hard drives.

Vl Let's face it,computers are made as cheap as possible and reliability
Vl is expensive.
Vl A hard drive lasts longer if it isn't running.

Vl Thanks

Vl Vlad

... That was a fascinating period of time for electronics