Patent ID: 7777463

Claim:
A method comprising: coupling a variable output DC power source to power control circuitry wherein said power control circuitry comprises source type recognition circuitry and said source type recognition circuitry comprises detection circuitry; detecting a type of said variable output DC power source in response to said coupling operation using said source type recognition circuitry, said detecting including sending an interrogation signal from said power control circuitry to said variable output DC power source and evaluating a response to said interrogation signal, said evaluating comprising: analyzing said response using said detection circuitry and determining said type of said variable output DC power source based on said analyzing, said analyzing comprising comparing said response to a plurality of voltage or current levels; and controlling said variable output DC power source in response to said detecting said type of said variable output DC power source using said power control circuitry, wherein said interrogation signal comprises a current signal sent via a control path from said power control circuitry to said variable output DC power source, and wherein said response comprises a voltage level at a control terminal of said variable output DC power source coupled to said control path, said voltage level representative of said type of said variable output DC power source, wherein said variable output DC power source comprises voltage feedback circuitry to receive a reference voltage and a signal representative of an output voltage of said variable output DC power source, said voltage feedback circuitry also coupled to a feedback node, and wherein said power control circuitry comprises a control node coupled to said detection circuitry, said control node coupled to said control path, said detection circuitry configured to analyze said voltage level at said control terminal and determine said type of said variable output DC power source in response to said voltage level.