Works finally perfectly with projector and HDTV

I bought this part, as my recently acquired Denon AVR-X1100W has only one HDMI output - and I need a switch between my older Panasonic HDTV as well as my also recently acquired this Acer H6520 projector.

First, the part did not want to work - no trace of the simultaneous display on both display units. I thought of Split was defective. It was only when I took the HDMI / MHL port on the projector, the matter went suddenly. However, this is strange, the MHL is described as follows by Acer:
"The MHL connectivity (via MHL / HDMI port) allows you to transfer an uncompressed digital HDMI signal from your smartphone while it is being recharged at the same time via the connection. Using the unique optional Acer MHL wireless adapter, the contents via WiFi Miracast display, WiDi Wireless Display or DLNA be transmitted even wirelessly from a video source to the projector. "

Apparently you go here is to get through this port voltage goes back to the splitter. And that should not be that this is a requirement - for why the part has its own power supply? This is a point deduction - for why something is not in the (not so short and unnecessary) instructions with it ??

Oh, no power supply Nothing works (purchase of January 2015) with me. This must be enabled. But now it works - much better than a previously used HDMI matrix of Kinivo.