The Larson Scanner is designed to run off of 3 V DC, if you use the standard red LEDs. You can swap out and use larger resistors (say, 100 – 150 ohm), if you’d like to run it off of 5 V DC. As far as current goes, it’s under 50 mA, max.
Now, I don’t know what the output of your motion detector looks like, but you also need to think about that, and how it relates to the Larson Scanner. :)
