draythomp:
The ones I have supply a constant 350ma until the load resistance drops enough to cause it to shut down. On the high side, they max out at a little over 11V and don't go any higher. Carefully hooking it to the VIN on an arduino (UNO), they seem to work fine. The problems may come when the combination of arduino and other devices need more than the 350ma and the thing shuts down.
But isn't that an important issue? These LED drivers are sensitive to the load they're driving; too little load and they shut off, too much load and they shut off. Only under fairly specific circumstances would you have a circuit that could keep that constant load.