Devantech multichannel relay module boards devantech usb rly08b the usb rly08b relay module board has 8x volt free contact relay outputs each having a current rating of up to 1a the board is powered from any standard usb bus and the unit has an exceptionally low maximum current consumption of approx 90ma with all relays on all relays are of the spco single pole change over type and the normally open normally closed and common pins are all available on the screw terminals control of th