Power supply size

Hi
I am upgrading my rostock 3d printer to a smoothieboard and upgrading to a e3d chimera dual extruder. I started with a E3D V6 and ramps 1.4.
I am wondering what current rating of power supply I should get? I have 2 16amp power supplies that currently power my ramps board,but I noticed that there is only one 12V input so I need to get a larger power supply.
The one 16 amp power supply has a 5V out so I can use it for the 5V in on the Smoothieboard.
I have seen power supplies that use a Watt rating instead of an amp rating so what would be the approximate size in both ratings? Is the conversion just P = V*A?
I will probably upgrade to a LCD screen so I will need a power supply big enough for it as well.
Thanks
Tanner

Yes the conversion is P = V * A. But if you choose a LED power supply, these have a voltage adjustment and you may wish to turn the voltage up to e.g. 14V to speed up bed heating. So allow extra power for this.

I suggest you choose a PSU rated at no less than 15A plus the heated bed current. So if you have a standard 10A heated bed, that's 25A, which is 300W at 12V. A 360W PSU will allow you some margin for turning up the voltage.

Btw support for my PanelDue colour touch screen control panel, which I developed for Duet printer electronics, should be available in Smoothieware soon.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].