AVR-Chat

Hi,

Sorry - a little off topic but...

I've got a Dell 1702FP LCD display, but unfortunately to not have the
power supply for it.

Standard power supply is a 14V @ 3A switch mode brick supply - similar
to most laptops etc.

I have a Toshiba laptop supply that is 15V @ 3A, and want to drop the
voltage down and use it for the LCD display. I measured this without
load at 15.2V

So, I placed a pair of 1N5404 diodes in series for a resultant drop of
around 1.4V (to be on the safe side).

The screen appears to run fine, but the diodes get rather toasty, and I
would ultimately like to be able to heatshrink them to hide them away
(they are about 50mm from the DC plug that goes into the monitor).

So, I thought about putting another pair in parallel to reduce the
current through each device with the hope of reducing the temperature. I
could place maybe 4 pairs in parallel if that will reduce the heat.

Am I on the right track? Is there a better way to approach this?

The power supply is sealed (glued), and I'm not sure what they are like
inside - whether they are potted in resin etc or whether they can be
adjusted a little?

Had anyone tried a similar thing?

I'm sure the diodes are ok at this running temp - just that I'm not
happy about how hot they are, and I'm not sure if I could heatshrink
them at current temps (with 2 parallel pairs each device is running at
surface temp of around 70C. With only 1 pair in series they were 100C!)

Any help would be greatly appreciated.

Of course I could always buy a replacement psu, but I can't find one
here in Australia at a reasonable price, and the ones on eBay USA are
about US$19 + the same again for shipping.

Many thanks in advance
Dean