I have a laptop, its power supply -- AC adaptor just gone. I need to get a replacement. but the one quoted from manufacturer is very expensive. I want to get one from the market. The original AC adaptor's spec is Output 20V, 300mA. I saw two in the market:
1. Output voltage 20Vdc, Max O/P 4.5A
2. Universal Laptop Power Supply -- 19V 4.74A
Are they OK for my laptop? Which one is better?