What's the best way to preserve a HDD by software stopping the power?

On Wed, 26 Sep 2018 10:28:30 +0200, "R.Wieser"
wrote:

Mike,

I put a switch in the +5V and +12V on mine.
Takes a few clicks to take it offline so you can cut the power safely.

And I hope you *never* forget to shut your computer down first, otherwise
its very likely it gets corrupted (nonwithstanding the fact that the NTFS
filesystem has already mechanisms in place to recover from it, and you won't
even notice it most of the time)

(some removable drive bays even offer a magnetic mechanism to lock the bay
in place to fix exactly that kind of mind-lapse problems)

As you feel confident enough about electronics to put a switch into those
lines, maybe you should think of (or google for) a solution that will
disallow you to power-off a drive thats already been powered on.

One of those solutions could involve a (rather oldfashioned, but still
applicable) use of a relais.

What is a relais?

Regards,
Rudy Wieser

On 10/16/2018 8:07 PM, Lucifer wrote:
On Wed, 26 Sep 2018 10:28:30 +0200, "R.Wieser"
wrote:

Mike,

I put a switch in the +5V and +12V on mine.
Takes a few clicks to take it offline so you can cut the power safely.

And I hope you *never* forget to shut your computer down first, otherwise
its very likely it gets corrupted (nonwithstanding the fact that the NTFS
filesystem has already mechanisms in place to recover from it, and you won't
even notice it most of the time)

(some removable drive bays even offer a magnetic mechanism to lock the bay
in place to fix exactly that kind of mind-lapse problems)

As you feel confident enough about electronics to put a switch into those
lines, maybe you should think of (or google for) a solution that will
disallow you to power-off a drive thats already been powered on.

One of those solutions could involve a (rather oldfashioned, but still
applicable) use of a relais.

What is a relais?

Regards,
Rudy Wieser

think *relay*


Rene

Lucifer,

What is a relais?

A relays is a pushbutton which uses an electromagnet instead of a finger.

http://www.galco.com/comp/prod/relay.htm

In the above image the "movable armature" will be pulled down when the
"electromagnet or coil" gets powered, causing the "movable contact" to touch
the "stationary contact", thereby closing the circuit and thus powering the
"load" (a lamp, motor, radio, computer or whatever else you want).

Now imagine the "load" is a lamp, and the "electromagnet or coil" wires are
connected to the "load". Also imagine another pushbutton (of the normal
push-by-finger type) over the "movable contact" and "stationary contact".
The lamp will stay out up until you press the pushbutton. But that also
powers the "electromagnet or coil", which causes the "movable contact" to
connect with the "stationary contact", effectivily taking over the function
of the pushbutton. The end effect is that as long as there is power the
lamp wil stay lit.

When you than remove the "power supply" the lamp will go dark (duh :-), but
*stay* that way even if power is re-applied.

Now replace the lamp with the harddisk the OP was talking about , and you
would have a drive you could switch on any time you like, but not be able to
switch off again (and possibly loose information or even corrupt the drives
contents) unless you switch the computer itself off (or possibly have it
reboot).

Regards,
Rudy Wieser

P.s.
Relays come with single "on" switch (like in the image), but also with "off"
or with both, and with more than one of them. A relays for a diskdrive
would need at least two "on" ones, as both the 12v and 5v need to be
switched.

Rene,

What is a relais?

think *relay*

Whoops. Used the Dutch name and did not even notice it. :-(

Thanks for the heads-up. But now I feel like an ass for having posted a
noobs explanation in regard to it ...

Regards,
Rudy Wieser

Lucifer, others,

In the above image the "movable armature" [snip]

I mistakingly posted a page link instead of just to the image (its about two
screens down). Here is the image for quick reference:

http://www.galco.com/images/moreinfo/relay_diagram.gif

Regards,
Rudy Wieser

R.Wieser wrote:
Rene,

What is a relais?

think *relay*

Whoops. Used the Dutch name and did not even notice it. :-(

I think the word 'relais' stems from French, at least the French use
the same word.

BTW, are you Dutch? Because of your (first and last) name, I assumed
you were German.

Frank,

BTW, are you Dutch?

Yep. Born and raised.

Because of your (first and last) name, I assumed
you were German.

My great-great-great (-great?) father moved from Germany to the Netherlands
(probably looking for work). So yes, my last name is something german
(never worked out what exactly though). As for my first name ? I have no
idea where it came from. Though my parents *intended* to just call me
"rudie". It was a city official which put the "rudy" name on the birth
certificate. As changing it would have been a big hassle they just left it
that way.

Regards,
Rudy Wieser

R.Wieser wrote:
Frank,

BTW, are you Dutch?

Yep. Born and raised.

Because of your (first and last) name, I assumed
you were German.

My great-great-great (-great?) father moved from Germany to the Netherlands
(probably looking for work). So yes, my last name is something german
(never worked out what exactly though). As for my first name ? I have no
idea where it came from. Though my parents *intended* to just call me
"rudie". It was a city official which put the "rudy" name on the birth
certificate. As changing it would have been a big hassle they just left it
that way.

Thanks for the info, Rudy.

As they say "If you ain't Dutch, you ain't much!" :-)