Hard Drive Brushless DC Motor Controller

[Andrew]

I have an old Western Digital Caviar 22500 hard drive that failed. I
hate to see good electronics go to waste. I salvage almost anything.

I am trying to get the hard drive spindle brushless DC motor to run.
What better controller than the one that came with the hard drive? I
will save me the trouble of building one - these circuits are
complicated. When I tried it, the motor powers off after about one
minute.

It seems that the hard drive does its initial diagnostics and realizes
that there is an error (no read/write heads), and powers off. I cannot
figure out how to stop the motor controller from shutting down.

The motor controller IC is UCC3285QP. I cannot find specs on this part
or similar ones with the same pinout configuration. I'm at a dead end.

Does anyone with knowledge on hard drive circuitry have any clues on
how to prevent the motor controller from shutting down. I don't want
to have a motor that's useless or expensive to operate.

 

[Gareth Magennis]

You can buy a used one from Ebay for less than 10 dollars. You could either
swap parts or use it as it is.



"Andrew" <mine_only_mine2222@yahoo.com> wrote in message
news:cdf4bdad.0410261459.498ff7f2@posting.google.com...

I have an old Western Digital Caviar 22500 hard drive that failed. I
hate to see good electronics go to waste. I salvage almost anything.

I am trying to get the hard drive spindle brushless DC motor to run.
What better controller than the one that came with the hard drive? I
will save me the trouble of building one - these circuits are
complicated. When I tried it, the motor powers off after about one
minute.

It seems that the hard drive does its initial diagnostics and realizes
that there is an error (no read/write heads), and powers off. I cannot
figure out how to stop the motor controller from shutting down.

The motor controller IC is UCC3285QP. I cannot find specs on this part
or similar ones with the same pinout configuration. I'm at a dead end.

Does anyone with knowledge on hard drive circuitry have any clues on
how to prevent the motor controller from shutting down. I don't want
to have a motor that's useless or expensive to operate.

 

[Andrew]

I would still rather get the hard drive motor controller on the hard
drive circuit board to work without shutting down. I would only pay
extra cash if I had an immediate use for the motor and wanted it
working right away.

So far the best I am able to get is applying a low voltage to pin 36
of the UCC3285QP. It stops the drive from powering down but now the
motor speed becomes unsteady and more noisy.

It seems I just need to figure out how to prevent the UCC3285QP from
knowing that it has to stop the motor, or get it to run independently
from the rest of the hard drive circuitry. But lacking any data sheet
or at least a pinout configuration, I am clueless.


"Gareth Magennis" <sound.service@btconnect.com> wrote in message news:<clqot4$6rb$1@sparta.btinternet.com>...

You can buy a used one from Ebay for less than 10 dollars. You could either
swap parts or use it as it is.

 

[Andrew]

I figured out a way!

I was focusing only on the motor controller IC. I then shifted focus
to other parts of the circuit. I thought that if I could trick the
circuit into thinking that there's a read/write head, then maybe it
would not shut down.

I made a connection from one of the pins leading ot the read heads and
connected it to a digital line that gives a lot of alternating ones
and zeros.

It worked. The motor starts up and remains running smoothly. So I
saved myself buying or building a brushless DC motor controller.



(Andrew) wrote in message news:<cdf4bdad.0410282026.78b45281@posting.google.com>...

I would still rather get the hard drive motor controller on the hard
drive circuit board to work without shutting down. I would only pay
extra cash if I had an immediate use for the motor and wanted it
working right away.

So far the best I am able to get is applying a low voltage to pin 36
of the UCC3285QP. It stops the drive from powering down but now the
motor speed becomes unsteady and more noisy.

It seems I just need to figure out how to prevent the UCC3285QP from
knowing that it has to stop the motor, or get it to run independently
from the rest of the hard drive circuitry. But lacking any data sheet
or at least a pinout configuration, I am clueless.


"Gareth Magennis" <sound.service@btconnect.com> wrote in message news:<clqot4$6rb$1@sparta.btinternet.com>...
You can buy a used one from Ebay for less than 10 dollars. You could either
swap parts or use it as it is.