Hi, i have got a Panasonic NV-GS500 from a friend.
I want to run it with the electrical cable instead of batteries. All i can see are inputs for USB, firewire (i-link), input for audio/video connection and one for an external mic. Where to put the elec.cable in?

There should be a dummy battery with a cable attached to it. That cable gets plugged into the battery charger on one end, and the battery slot on the camera.