I have a hard drive that I would like to operate off of a battery (I know it
sounds really really strange....so email me if you want to know why). How
much voltage would I need? Could I use a 9-volt battery?

The hard drive would normally require two supply rails.
+5 Volt and +12 Volt DC.
These supply rails will need to supply a fairly heavy current mainly for the
start-up of the spindle motor.
They should both be regulated voltages so as to avoid over voltage damage to
the sensitive electronics.

I don't think that a single 9-Volt battery would be suitable.


"michaaal" wrote in message
news
I have a hard drive that I would like to operate off of a battery (I know
it
sounds really really strange....so email me if you want to know why). How
much voltage would I need? Could I use a 9-volt battery?

Current drain will very depending on the age and size (physical) of the
drive,.
as well as the number of heads (the mass of the positioning mechanism)
You could use a 12 volt battery and use a 5 volt regulator off that. 12
volts is usually used for the spindle and positioning motor, and the 5 volts
is for the logic.

The small drives used in laptop computers only use one rail, I believe it's
5 volts, this you might be able to power from 9 volts, with a suitable vreg.
But if the 9 volt battery is one of those rectangular, common as **** ones,
it won't run for long

Ray


"michaaal" wrote in message
news
I have a hard drive that I would like to operate off of a battery (I know
it
sounds really really strange....so email me if you want to know why). How
much voltage would I need? Could I use a 9-volt battery?

Two questions please....

1) If I do use a 9-volt battery, would I still need a regulator? (I just
need enough power to make the motor spin.....no data is actually going to be
written to the drive....I know that sounds really odd).

2) What does a regulator do? (I am new to the electronics world...sorry)



"Nirodac" wrote in message
news:7wB4b.123211$K44.10881@edtnps84...
Current drain will very depending on the age and size (physical) of the
drive,.
as well as the number of heads (the mass of the positioning mechanism)
You could use a 12 volt battery and use a 5 volt regulator off that. 12
volts is usually used for the spindle and positioning motor, and the 5
volts
is for the logic.

The small drives used in laptop computers only use one rail, I believe
it's
5 volts, this you might be able to power from 9 volts, with a suitable
vreg.
But if the 9 volt battery is one of those rectangular, common as ****
ones,
it won't run for long

Ray


"michaaal" wrote in message
news
I have a hard drive that I would like to operate off of a battery (I
know
it
sounds really really strange....so email me if you want to know why).
How
much voltage would I need? Could I use a 9-volt battery?

A regulator is a device that will drop a voltage from let say in your case 9
volts to 5 volts. It will also keep the 5 volts stable with fluxuations of the
voltage to the input of the regulator up to a point. It will also keep the
output voltage stable with the load on it even if it is varies, again, up to a
point. A overload should shut down the regulator.

Sal

michaaal wrote:

Two questions please....

1) If I do use a 9-volt battery, would I still need a regulator? (I just
need enough power to make the motor spin.....no data is actually going to be
written to the drive....I know that sounds really odd).

2) What does a regulator do? (I am new to the electronics world...sorry)

"Nirodac" wrote in message
news:7wB4b.123211$K44.10881@edtnps84...
Current drain will very depending on the age and size (physical) of the
drive,.
as well as the number of heads (the mass of the positioning mechanism)
You could use a 12 volt battery and use a 5 volt regulator off that. 12
volts is usually used for the spindle and positioning motor, and the 5
volts
is for the logic.

The small drives used in laptop computers only use one rail, I believe
it's
5 volts, this you might be able to power from 9 volts, with a suitable
vreg.
But if the 9 volt battery is one of those rectangular, common as ****
ones,
it won't run for long

Ray


"michaaal" wrote in message
news
I have a hard drive that I would like to operate off of a battery (I
know
it
sounds really really strange....so email me if you want to know why).
How
much voltage would I need? Could I use a 9-volt battery?

Placing 9 volts on a 5 volt rail will most likely cause the smoke stored in
the IC's to be released. Once the smoke has been released from the IC's
they become useless, unless you have some magic way of putting the smoke
back in.
9 volts on the 12 volt rail can also cause problems, when motors don't
spin, properly, they can over heat, and cause problems.
The motor isn't connected directly to the power supply pins, anyway. The
motors are actually controlled by the electronics on the circuit board, and
are monitored for correct rotational speed, up to 10,000 rpm on some drives.
The motors typically have multiple coils, and are really closer to a stepper
motor than a conventional DC motor. There are no brushes and no commutator
on these motors.
Perhaps you could provide more details, and someone here could find a
solution to your problem.
You should also be aware that some disks won't spin until they receive a
command from the controller, or they have the correct option jumper
selected.
5 volt regulators are as common as flies. They are simple to use (they only
have three pins, input, output, and a common ground). You'll need a
capacitor on the input and one on the output, that's it.
And you don't need to apologize for not knowing something, at one time or
another, everyone in this newsgroup has asked a question that someone else
new as just general common knowledge, it's part of the learning curve. Now,
just how do rocket engines work.

Ray


"michaaal" wrote in message
...
Two questions please....

1) If I do use a 9-volt battery, would I still need a regulator? (I just
need enough power to make the motor spin.....no data is actually going to
be
written to the drive....I know that sounds really odd).

2) What does a regulator do? (I am new to the electronics world...sorry)



"Nirodac" wrote in message
news:7wB4b.123211$K44.10881@edtnps84...
Current drain will very depending on the age and size (physical) of the
drive,.
as well as the number of heads (the mass of the positioning mechanism)
You could use a 12 volt battery and use a 5 volt regulator off that. 12
volts is usually used for the spindle and positioning motor, and the 5
volts
is for the logic.

The small drives used in laptop computers only use one rail, I believe
it's
5 volts, this you might be able to power from 9 volts, with a suitable
vreg.
But if the 9 volt battery is one of those rectangular, common as ****
ones,
it won't run for long

Ray


"michaaal" wrote in message
news
I have a hard drive that I would like to operate off of a battery (I
know
it
sounds really really strange....so email me if you want to know why).
How
much voltage would I need? Could I use a 9-volt battery?

And you don't need to apologize for not knowing something, at one time or
another, everyone in this newsgroup has asked a question that someone else
new as just general common knowledge, it's part of the learning curve.

Thank you for saying this. I can't tell how many times I have been
ridiculed
in other newsgroups for politely asking a question that others seem to think
is common knowledge to the group. You guys seem ver nice here.