On 01/29/05 11:16 ET, The8thst said...
You're correct, you don't need the 12v hooked
up to anything UNLESS you are using the connecting
block to power an IR receiver that needs 12v to
operate.
If I remember right (I am speed reading here) the 791 is an amplified block. That means that it needs a power supply. It has a jack for a sensor.
I think someone suggested connecting an IR output to the input of this block. This is correct, but do not take the elegant approach of using a mini plug into the sensor input to make this connection. That will short the power supply. Just use the screw terminals.
Also, I believe the tip of mini plugs is the plus, not the minus.