A very nice thing to have around - a little lab grade power supply with meters.
You can get these pretty cheap on the auction sites. The cheap ones don't put out a lot of current, but you aren't going to use them for a 10A gizmo. What they do:
1) The show you the current being pulled on a meter (so you can unplug things fast).
2) They let you set a current limit with a knob (so you don't put a lot of current in)
3) They show you the voltage on a meter
4) They give you a knob to slowly adjust the voltage.
Much less stress powering up your new board with one of those than just plugging it into a 12V 30A supply.
You can get these pretty cheap on the auction sites. The cheap ones don't put out a lot of current, but you aren't going to use them for a 10A gizmo. What they do:
1) The show you the current being pulled on a meter (so you can unplug things fast).
2) They let you set a current limit with a knob (so you don't put a lot of current in)
3) They show you the voltage on a meter
4) They give you a knob to slowly adjust the voltage.
Much less stress powering up your new board with one of those than just plugging it into a 12V 30A supply.