power supply - 3 wires on a (bipolar) DC plug - what are they for? - Electrical Engineering Stack Exchange
Laptop AC Adapter for Dell Inspiron 300M/500M/600M/700M - Walmart.com
How to modify a DELL or aftermarket replacement charger to work with HP laptop - YouTube
Hacking a Dell power adapter — final (not really) | My Not-So-Boring Life
How does a Dell laptop charger with a pin of the same wattage & specs which fits perfectly into an HP not work because it knows it is not an HP charger