1. A programmable apparatus adapted to be programmed by a programming device, comprising: a circuit board having first and second nodes, and an input power port coupled electrically to said first node for receiving input power, said second node being adapted to be coupled electrically and selectively to the programming device; a programmable device mounted on said circuit board and having an input power terminal coupled electrically to said second node; an electronic component unit mounted on said circuit board and coupled electrically to said first node; and a switch mounted on said circuit board and interconnecting said first and second nodes, said switch being operable between a closed state, wherein said programmable device and said electronic component unit receive the input power via said input power port, and an opened state, wherein said programmable device is disconnected from said input power port such that the programming device can be coupled to said second node for supplying input power to said input power terminal when programming said programmable device.