Hi, all...

I recently decided to 'externalize' my DVD reader and DVD writer, by
using little USB converters. They seem to work fine, and were
inexpensive.

Problem is, one of the transformers which came with one of them causes
a lot of EM interference with my PC speakers. I hear a rather loud hum
when it's all connected up. Kind of distressing. The other one seems to
cause no adverse effects.

I'm wondering if putting an IDE power splitter off the 'good'
transformer and connecting both drives to it will work. I know that the
rated amperage of the transformer is only slightly higher than the
rated draw of one drive, so I would not expect them _both_ to work at
the same time. But if I only ran one at once, I wonder if that would
work.

Or to put it another way: does a CD/DVD drive draw any amperage when
it's not actually spun up and working...?

I guess the best route would be to deal with the 'faulty' transformer -
get a replacement or something... But, this might serve as a stopgap,
if there's no risk of damage or brownouts.

Thanks!

BD

Previously BD <bobby_dread (AT) hotmail (DOT) com> wrote:
Hum? That is strange. Modern PSUs use HF transformers they operate
at >= 50kHz, i.e. inaudible. Maybe you just have an old-fashioned
ground loop that has nothing to do with the PSU? Or did you indeed get
a PSU based on outdated 50/60Hz tranfsormer technology?

If it is a modern swithcing PSU and hums, then it is badly broken and
should not be used for anything.

Not a good idea. On start-up both drives will draw power, spinning up
DVDs in them. That should not kill the PSU but may cause the drives not
to start propperly. Also DVD drives are power-hogs.

Arno

To be clear - it's not a PSU per se - it's a small black 'brick'
(1"x3"x6") which sits between the AC outlet and the drive. Same as
you'd get with most AC adapters.

And, to be clear, it's not the adapter which hums. When I plug it in,
my PC sound system hums. Which tells me there's some nasty interference
going on somewhere.

Anyway. Yeah, I guess it's not the best idea. I'll see if I can
exchange the thing.

Previously BD <bobby_dread (AT) hotmail (DOT) com> wrote:
That is what I meant. That is also a PSU (Power Supply Unit).
A "transformer" is an heavy object, mostly consiting of iron.
A PSU is the generic term for something that gives power.

Agreed. There is possibly an isolation problem with this PSU.
I would advise you to stop using it immediately, it may be dangerous,
possibly lethal, if used unconnected to firmly grounded equipment.

The power-converter can usually not hum, since it operates at
inaudibly high frequencies.

Do so. If you cannot, discard it anyways, see above.

Arno

Sage advice. Turns out the thing doesn't work as well as I'd hoped
anyway - half my burns get verification errors. Oh well. I'll jam the
burner back in the machine and (assuming my burns are back to normal),
just get rid of the thing.