lm338k problem

Hi all not sure if this is the write place to post this question but here goes.

i wanted to power my playstation 2 from my car so i decided to use the adjustable lm388 the 5amp version the k metal package type anyway i got it to run at exactly 8.5volts which is the required voltage and the current drain was between 2-2.5 amp when the ps2 was running but and heres the big but bearing in mind i used an ali box to mount the reg to within a minute the actual ali box got so hot that u couldnt touch it this also happens with the 3 pin package as well , so can some advise me on what i have done wrong or how i can rectifier the heat/ current problem , ive done abit of reading up and as far as i can tell the difference between vin and vot is converted into wattage ( heat).
I need help lol
tanx guys, scott

Your car battery is up to 14.4V when it is overcharging the battery. The output of the regulator is 8.5V so there is 5.9V across it.
If the current is 2.5A then the power is 5.9V x 2.5A= 14.75W worth of heating. The regulator needs to have an extruded aluminum heatsink with fins and maybe a fan.
If the regulator gets too hot then it will shut down to protect itself.

thx for the speedy reply, so can anyonw suggest an easy and compact circuit to run the ps2 from the 13.8v car battery, needs to be 8.5v/2.5 amp out

tnx guys

Google "Playstation car adapter". I doubt you could build one much if any cheaper.

yeah can get 1 for 14.99 but building 1 would be more satisfying which is why i want a circuit suggestion

scott1976 said:

yeah can get 1 for 14.99 but building 1 would be more satisfying which is why i want a circuit suggestion

Click to expand...

Why not try a switching regulator? Definatelya bit harder to implement, but if you want to build a compact PSU, then it's probably the way to go..

Here's a link to some info that may be useful..

**broken link removed**