Ok for class, I had this 7segment display(common cathode) and it worked great. Then I bought more, but I bought the common anode kind. And this time, it doesn't work so well. For some reason the numbers change when i wave my hand over the power supply; im not even touching it. I'm using cd4543 decoder with the ld5161. ..wait i just tried again, and nothing happens but when i pick up the power supply all the segments turn on even though the switch is on 0000 wtf... can someone tell me why my seven segment display does wierd things when i mess with the batteries?