Every tinkerer should own at least one good regulated power supply [u]with adjustable voltage and current[/u].
You might buy one for around 50$. It will be worth every penny, avoiding the blue smoke.
But almost every tinkerer surely has got on or more laptop power adapters laying around since the laptop died or got obsolete. These devices usually deliver 19V at 3-4A.
You may want to look at your favourite dealer and search for a DP30V3A (~20$).
I used two laptop power adapters, which outputs are connected in serie. So I have 38V 3A DC input, just perfect to feed this tiny module.
Add a couple of banana plugs, a power switch and you have got a very nice and powerful regulated power supply with integrated digital display, capable of delivering 0-30V and 0-3A.