power supply equipment includes an adapter which converts power from a power source to dc power for powering an electronic device . the power supply equipment includes circuitry which produces a data signal for use by the electronic device to control power drawn by the electronic device . a cable extends from the adapter . the power supply equipment further includes a tip which has an input side and an output side . the input side of the tip is detachable mateable to the cable . the output side of the tip is detachably mateable to the electronic device . the tip output side has a shape and size dependent on the shape and size of a power input opening of the electronic device . the tip provides the data signal , as well as the dc power , to the electronic device . different tips may be used to provide appropriate data signals to different electronic devices .