Originally Posted by Ericko
*A PSU wuth 19.5V and less than 4.62A is NOT OK, if your laptop needs the full 4.62A, it will try to get them from the PSU and the PSU will respond dropping the voltage, so at the end you will get less voltage and less current that the one you need
Actually what usually happens in that case in real life is that the PSU gets to hot and burns itself out.
To give you the actual figures the Energy Knight P70W D-D PSU (which is a multi PSU wich uses fuses with a resistor in it to regulate the current but has interchangeable tips, so it doesn't really have to be jerry rigged - my father has just lost the other fuses with different resistors) has at the moment the 20 W fuse/resistor combination, and it's rated at 70 watts with input power from 11-15V, and output dropping from 4.8 to 3 A with fuses/resistors from 15-24V.
The original 220V PSU for the computer is rated at 19V, 3.42 A and 65 watts.
To me those numbers are pretty similar, since the 12V psu should be able to deliver the necessary amps in that area. I may try it only for a few minutes and measure the current from the psu with a multimeter.
And for the record, Ericko: A stable 12V dc-dc psu (and this one's rock solid, it has several hundred hours use and never a problem) will set you back a lot more than $50! Especially here in Norway. I'm guessing you didn't notice that this was a car PSU.