The ATX standard followed some manufacturers design to have power supplies also supply a standby voltage, so that most of the computer system could be powered off after preparing for hibernation or shutdown, and powered back on by an event. When the computer is powered down but the power supply is still on, it can be started remotely via Wake-on-LAN and Wake-on-ring or locally via Keyboard Power ON (KBPO) if the motherboard supports it. This standby voltage is generated by a smaller power supply inside the unit. The standby power source was a small linear power supply with conventional transformer, which was later changed to a switching power supply, sharing some components of the main unit due to cost- and energy-saving requirements.