Method and apparatus for selecting the output of programmable power adapter

An apparatus of programming an output of a programmable power adapter, comprising:

• a control circuit sending a signal to a device, in which the device is coupled to the signal to determine the level of the signal, the control circuit checks the level of the signal for determining an output voltage of the programmable power adapter in accordance with the level of the signal;
• wherein an identification circuit installed in the device is coupled to the signal to determine the level of the signal;
• the output voltage of the programmable power adapter is coupled to the device to provide a power for a load of the device.

A programmable power adapter, comprising:

• a control circuit sending a signal to a device, in which the device is coupled to the signal to determine the level of the signal, the control circuit checks the level of the signal;
• and
• a programmable power supply circuit generating an output voltage of the programmable power adapter and determining the output voltage in accordance with the level of the signal.