What is this diode doing?

Discussion in 'General Electronics Chat' started by moeburn, Dec 3, 2013.

  1. moeburn

    Thread Starter Member

    Aug 16, 2013
    Very basic question here. I have a guide on how to take the wireless controller receiver card out of an Xbox 360 motherboard, solder a USB cable to it, and plug it into a computer to use the wireless controllers on a PC. The guide says to use a 1n400x diode in between the red +5v USB wire, and the vIn pin on the board.

    What is this diode for? Is it just a safety thing, to prevent current flowing in the wrong direction in case you accidentally solder incorrectly and fry your PC's usb port?
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
    It does sound like blocking diode.
  3. wayneh


    Sep 9, 2010
    It could be used do drop voltage (~0.7V) if the board is not meant to operate at 5V.