The PICAXE-28x/40xProto Board (AXE022) can be powered in three ways.
1) External 4.5V battery or 5V regulated DC supply
2) 9V DC regulated supply with added on-board regulator RG1 (sold seperately)
When used with an external battery or regulated 5V supply, jumper J3 must be in the left hand position. In this case the supply voltage (connected to connector CT2) is applied directly to all components on the protoboard. When used with an external 9V DC regulated supply (connected to connector CT2), a 78L05 regulator must be soldered in position RG1 and the jumper link J3 completely removed. The 78L05 provides a regulated 5V supply to the components on the board (maximum current capacity 100mA). When used with the PICAXE NET board, the power supply to the protoboard is sourced from the PICAXE.net board(7805 5V 1A regulator from 9V supply). In this case Jumper J3 must be in the right hand position and no external supply should be connected to connector CT2.