from Viva Nintendo

Yesterday we got the chance to get two wii next to each other. We were playing with one while updating the other but we only got one TV so we had to keep switch the video cables from one Wii to the other to keep tracking of the update progress. In this plug and unplug we realize that we weren’t switching the sensor bar: there was just one sensor bar out, always connected to the same Wii, but both consoles were able to receive the signal from each wiimotes.

This leads me to believe that the sensor bar doesn’t send any signal to the Wii, it just got the power from the console and send a pace signal to be picked by the wiimote and not the other way around, so most of the job is done by the wiimote.

VelvetHammer make a good point, the sensor bar is not the receiver the wiimote is. This way the batteries from the wiimotes don’t keep draining. The wiimote is the actual receiver.