POWER SUPPLY WITH VOLTAGE OUTPUT RESPONSIVE TO LOAD DEMAND

摘要

A method for a power adapter to selectively provide a first and a second output voltage may comprise coupling a rectified and filtered transformer input signal to a primary winding of a transformer. The secondary winding thereof may comprise a first tap associated with the first output voltage and a second tap associated with the second output voltage, the first and second taps being configured to be selectively coupled to and uncoupled from an output of the power adapter. The output current drawn at the output of the power adapter may then be sensed. When the sensed output current is determined to have exceeded a predetermined threshold, the output of the power adapter may be switched from the first to the second tap by uncoupling the first tap from the output of the power adapter and coupling the second tap to the output of the power adapter.

主权项

1. A power adapter, comprising:
a rectifier and filter configured to be coupled to an input alternating current (AC) source and to generate a direct current (DC) transformer input signal; a transformer, the transformer comprising a primary winding coupled to the transformer input signal and a secondary winding coupled to an output of the power adapter; a current sensor configured to sense an output current drawn at the output of the power adapter and to generate a current sense signal; and a controller configured to a) regulate a voltage at the output of the power adapter by controlling current flowing through the primary winding of the transformer and b) select an output voltage from at least a first voltage and a second voltage based upon the current sense signal.