A power adaptor detection system includes a power adaptor device configured to receive electrical power at a first voltage and to convert the electrical power to a second voltage. The second voltage has a lower value than the first voltage. An identification generating circuit is coupled to the power adaptor device. The identification generating circuit is configured to convert a portion of the electrical power to a substantially constant value electrical current. An identification detection circuit is configured to detect the second voltage. Detecting the second voltage causes the identification circuit to determine the value of a pulse of the electrical current, wherein the value of the electrical current is an identification attribute of the power adaptor device.