a power feed device for an electrical component which improves the quality of transmission and reduces the mounting density of a printed circuit board in the power feed device or reduces the thickness of the printed circuit board and thereby realizes smaller size , provided with a power supply for supplying power , a printed circuit board having built - in signal line patterns , and a power bar having conductive projections provided in shapes and at positions corresponding to the shapes and positions of electrodes of the electrical component and provided outside of the printed circuit board , power from the power supply being supplied through the conductive projections of the power bar to electrodes of the electrical component .