Power supply question 18.5V @ 3amps

[Cunning Linguist]

Hi everyone, I have put together a small Jukebox for playing MP3's from my
laptop, I am wanting to power the laptop from the power supply that drives
the amp. The trannie is a 28-0-28 M0144, I think this only has a capacity of
2 amps. I can pick up about 35 volts from the positive rail that feeds the
pre amp outputs and cut it down to 18.5V with an appropriate adj vol reg but
I am concerned that there will not be enough amperage to run the laptop
(Compaq V300 @ 400mhz) is there a way to boost the amps to the laptop.
Cheers and thanks in advance
Tony..

 

[Eddie]

use a buck switchmode power converter, but this is boderline, as the amp
will take most of the power at volume, i suggest use the laptop mains power
supply as well. the laptop will want up to 60W i would think.

"Cunning Linguist" <tleathem@netspace.net.au> wrote in message
news:cqqovk$1ndq$1@otis.netspace.net.au...

Hi everyone, I have put together a small Jukebox for playing MP3's from my
laptop, I am wanting to power the laptop from the power supply that drives
the amp. The trannie is a 28-0-28 M0144, I think this only has a capacity
of
2 amps. I can pick up about 35 volts from the positive rail that feeds the
pre amp outputs and cut it down to 18.5V with an appropriate adj vol reg
but
I am concerned that there will not be enough amperage to run the laptop
(Compaq V300 @ 400mhz) is there a way to boost the amps to the laptop.
Cheers and thanks in advance
Tony..

 

[Cunning Linguist]

Hi Eddie, thanks for the reply, I think you may be right, tho I will take a
few voltage readings at various volumes and see how much effect that has,
might even put the multimeter onto amps and check that as well
Cheers
Tony..

"Eddie" <eddie_bounce@optusnet.com> wrote in message
news:41d0ebbf$0$5131$afc38c87@news.optusnet.com.au...

use a buck switchmode power converter, but this is boderline, as the amp
will take most of the power at volume, i suggest use the laptop mains
power
supply as well. the laptop will want up to 60W i would think.

"Cunning Linguist" <tleathem@netspace.net.au> wrote in message
news:cqqovk$1ndq$1@otis.netspace.net.au...
Hi everyone, I have put together a small Jukebox for playing MP3's from
my
laptop, I am wanting to power the laptop from the power supply that
drives
the amp. The trannie is a 28-0-28 M0144, I think this only has a
capacity
of
2 amps. I can pick up about 35 volts from the positive rail that feeds
the
pre amp outputs and cut it down to 18.5V with an appropriate adj vol reg
but
I am concerned that there will not be enough amperage to run the laptop
(Compaq V300 @ 400mhz) is there a way to boost the amps to the laptop.
Cheers and thanks in advance
Tony..