An LED power supply (LPS) (10) that is designed to replace conventional fluorescent lamps, which also include Compact Fluorescent Lamps (CFLs). The LPS (10) is comprised of three major elements: a power input circuit (PIC) (12), an LED Power Control Circuit (LPCC) (14) and an LED load 16. The PIC (12) can consist of either a d-c voltage source (12A) or an a-c voltage source (12B). The a-c voltage source (12B) is rectified and filtered to produce a filtered d-c voltage output (11′) prior to being applied to an OR gate (12D) from where a filtered d-c voltage (21) is produced and applied to the LPCC (14) for further processing. The CPCC (14) functions to automatically monitor and adjust both the voltage and the current that is applied to a plurality of LEDS 71 that comprise the LED load 16. The LED load is typically configured in a series-parallel configuration.