48vdc Power Solution for Compaq KVM

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dedman

I recently acquired a Compaq 2x8 8 Port Kvm. Typically these are powered
from the facility power ina rack in a data center. The input voltage is
48vdc @ 300 ma.

I am looking for a solution to power the unit at home, and I was wondering
if anyone else has solved thsi problem, andf so, what was used in the
solution?

The connector is proprietary, but not a show stopper. i am sure I can
engineer something or add a different style input somwhere else on the
case.

Any thoughts, ideas or solutions?

Thanks in advance.
 
dedman said:
I recently acquired a Compaq 2x8 8 Port Kvm. Typically these are powered
from the facility power ina rack in a data center. The input voltage is
48vdc @ 300 ma.

I am looking for a solution to power the unit at home, and I was wondering
if anyone else has solved thsi problem, andf so, what was used in the
solution?

The connector is proprietary, but not a show stopper. i am sure I can
engineer something or add a different style input somwhere else on the
case.

Any thoughts, ideas or solutions?

Thanks in advance.
Click to expand...

Have a look on Digikey.comm .

Astec 48V @ 1.25A, page 1932 of the catalog, part # is 454-1165-ND, about $50.

It is depicted as an open frame supply. That means safety hazards galore.
There are exposed voltages in the supply (don't drop tools or instruments into
one, like I did). And 48VDC is pretty nasty as well.

Here is a datasheet for the Astec.

http://www.astec.com/products/datasheets/lp/lps50.pdf

Paul
 
Paul said:
Have a look on Digikey.comm .

Astec 48V @ 1.25A, page 1932 of the catalog, part # is 454-1165-ND,
about $50.

It is depicted as an open frame supply. That means safety hazards galore.
There are exposed voltages in the supply (don't drop tools or
instruments into
one, like I did). And 48VDC is pretty nasty as well.

Here is a datasheet for the Astec.

http://www.astec.com/products/datasheets/lp/lps50.pdf

Paul
Click to expand...

http://catalog.digikey.com/scripts/partsearch.dll?Detail?name=454-1165-ND

Paul
 
dedman said:
I recently acquired a Compaq 2x8 8 Port Kvm. Typically these are powered
from the facility power ina rack in a data center. The input voltage is
48vdc @ 300 ma.

I am looking for a solution to power the unit at home, and I was wondering
if anyone else has solved thsi problem, andf so, what was used in the
solution?

The connector is proprietary, but not a show stopper. i am sure I can
engineer something or add a different style input somwhere else on the
case.

Any thoughts, ideas or solutions?

Thanks in advance.
Click to expand...
Here's an enclosed switcher that supplies 48VDC at 0.8 amps for $28.99
http://www.mpja.com/productview.asp?product=16004+PS
 
I recently acquired a Compaq 2x8 8 Port Kvm. Typically these are powered
from the facility power ina rack in a data center. The input voltage is
48vdc @ 300 ma.

I am looking for a solution to power the unit at home, and I was wondering
if anyone else has solved thsi problem, andf so, what was used in the
solution?

The connector is proprietary, but not a show stopper. i am sure I can
engineer something or add a different style input somwhere else on the
case.

Any thoughts, ideas or solutions?

Thanks in advance.
Click to expand...

I don't know how adept you are at reverse engineering
circuits, but certainly this KVM has a step-down regulator
subcircuit inside right after the power jack. That may work
acceptibly from lower voltage increasing your options.

It may have a 48V fan in it though, powering from lower
voltage might run the fan at acceptible RPM still or might
instead be too low and you'd need to swap the fan (assuming
it has one).

There are quite a few options in smaller switchers, you'd
merely have to google search for them. 48V and roughly the
same current spec is fairly common for PoE applications, for
example,
http://store.wifi-parts.com/48v19wswposu.html
http://www.interprojekt.com.pl/100260v-48v30w-power-supply-routerboard-p-202.html
though I'd suspect a larger, better ventilated supply will
have a longer lifespan and easier to repair later should the
need arise, but it could depend on where you can mount it
too, this isn't really meant to be out around people (kids)
http://webtronics.stores.yahoo.net/4048siouposu.html
 
dedman said:
I recently acquired a Compaq 2x8 8 Port Kvm. Typically these are powered
from the facility power ina rack in a data center. The input voltage is
48vdc @ 300 ma.

I am looking for a solution to power the unit at home, and I was wondering
if anyone else has solved thsi problem, andf so, what was used in the
solution?

The connector is proprietary, but not a show stopper. i am sure I can
engineer something or add a different style input somwhere else on the
case.
Click to expand...


Before you purchase a power-supply...
try the KVM without one.

I have a Tripp-Lite kvm with a power jack on it...
but it turns out that the power source is optional
 
Interesting that it doesn't need a power supply. I just tried this one,
and did not get any display.

Thanks for responding. Appreciate it.
 
I don't know how adept you are at reverse engineering
circuits, but certainly this KVM has a step-down regulator
subcircuit inside right after the power jack. That may work
acceptibly from lower voltage increasing your options.

It may have a 48V fan in it though, powering from lower
voltage might run the fan at acceptible RPM still or might
instead be too low and you'd need to swap the fan (assuming
it has one).

There are quite a few options in smaller switchers, you'd
merely have to google search for them. 48V and roughly the
same current spec is fairly common for PoE applications, for
example,
http://store.wifi-parts.com/48v19wswposu.html
http://www.interprojekt.com.pl/100260v-48v30w-power-supply-routerboard-
p-202.html though I'd suspect a larger, better ventilated supply will
have a longer lifespan and easier to repair later should the
need arise, but it could depend on where you can mount it
too, this isn't really meant to be out around people (kids)
http://webtronics.stores.yahoo.net/4048siouposu.html
Click to expand...

There are no fans on this unit.

I did find a power supply in my vast array of junk here. It is 48vdc, but
now I just need to determine how to apply the power to the kvm. One way
it will get 48vdc, and if you reverse the polarity, it will be -48vdc,
which is normal telco voltage.

Unfortunately, Compaq kvm's (Made by Apex, which is owned by Avocent and
also makes Cybex) refer's to these units as 48vdc which would be
positive, but states they should be hooked up to -48vdc. I still need to
detemine the polarity of the kvm. There is a plus and minus marked but I
do not know which way to apply power to the + and - to give me -48vdc. It
would appear that the power supply is the least of my worries.

There jsut is not a lot of info regarding powering these up, which is why
I was hoping someone had already done this in some fashion or another.

Thanks for your input.
 
Interesting that it doesn't need a power supply. I just tried this one,
and did not get any display.
Click to expand...


Older, higher part count KVMs are more likely to need more
current than could be supplied by a PS2 or USB 5V lead... or
it could just be a design decision to not take current when
unnecessary (since they could operate under the assumption
that they're selling their KVM with another means to get
power).
 
There are no fans on this unit.

I did find a power supply in my vast array of junk here. It is 48vdc, but
now I just need to determine how to apply the power to the kvm. One way
it will get 48vdc, and if you reverse the polarity, it will be -48vdc,
which is normal telco voltage.

Unfortunately, Compaq kvm's (Made by Apex, which is owned by Avocent and
also makes Cybex) refer's to these units as 48vdc which would be
positive, but states they should be hooked up to -48vdc. I still need to
detemine the polarity of the kvm. There is a plus and minus marked but I
do not know which way to apply power to the + and - to give me -48vdc. It
would appear that the power supply is the least of my worries.

There jsut is not a lot of info regarding powering these up, which is why
I was hoping someone had already done this in some fashion or another.

Thanks for your input.
Click to expand...


Popping the cover off the KVM and tracing back the circuit
should also help to reveal polarity, and having a multimeter
handy might be (handy).
 
dedman said:
Interesting that it doesn't need a power supply. I just tried this one,
and did not get any display.

Thanks for responding. Appreciate it.
Click to expand...



I'm just saying that *my* KVM does not need a supply...
apparently yours does...but I thought it worth a try anyway.

I still wonder why my KVM has provisions for a supply if it doesn't need
one...
Oh well
 
I'm just saying that *my* KVM does not need a supply...
apparently yours does...but I thought it worth a try anyway.
Click to expand...
I still wonder why my KVM has provisions for a supply if it doesn't need one...
Click to expand...

If its a USB KVM, most likely because not
all USB ports can supply enough power.
 
If its a USB KVM, most likely because not
all USB ports can supply enough power.
Click to expand...


What are you babbling about now?

You can't take more than the 500mA max of USB from a PS2
port either and they're fused just as USB is (should be
unless board manufacturer was exceedingly cheap) so in any
case the USB port should be capable of at least as much as
the PS2.
 
What are you babbling about now?

You can't take more than the 500mA max of USB from a PS2
port either and they're fused just as USB is (should be
unless board manufacturer was exceedingly cheap) so in any
case the USB port should be capable of at least as much as
the PS2.
Click to expand...

The power connector is there to minimize the draw of power from the PS/2
port when folks are using the 5vStdby to power it. I've had PC's that would
not power on due to the number of items plugged into the standby 5v.

That's the only reasonable explanation that I can think of.

Maybe the circuits inside work better from a seperate power supply and you'd
see the difference in the display when running high resolutions?
 
What are you babbling about now?
Click to expand...

What are you pig ignorantly bullshitting about ?
You can't take more than the 500mA max of USB from a
PS2 port either and they're fused just as USB is (should be
unless board manufacturer was exceedingly cheap) so in any
case the USB port should be capable of at least as much as the PS2.
Click to expand...

Pity about the ones that cant supply 500mA, ****wit child.
 
The power connector is there to minimize the draw of power from the PS/2
port when folks are using the 5vStdby to power it. I've had PC's that would
not power on due to the number of items plugged into the standby 5v.

That's the only reasonable explanation that I can think of.

Maybe the circuits inside work better from a seperate power supply and you'd
see the difference in the display when running high resolutions?
Click to expand...

I agree and also think it's a bit hard on a PSU having the
5VSB rail nearer peak output if the system is left off a
large % of the time, when the PSU is only passively cooled.
In some PSU their casing does get a bit warm just sitting
like this and it can't be good for the 5VSB componentry to
run hot long term.
 
I think we'd all find it useful for you to list those that can't, Rod.
Click to expand...

Not even possible, ****wit child.

You'll find plenty of examples using groups.google

And just how many of you are there between those ears, ****wit child ?
 
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