Dear all, Most SMPS provide constant DC voltage (CV) with current limit. We look for SMPS which provide constant DC current (CC) with voltage limit. These constant-current (CC) SMPS will be used to supply a number of LEDs connected in series. A good designed CC SMPS should then supply the same output current no matter if it supplies 1 or more LEDs in series (though the maximum LED number is related to the voltage limit and the LED type). A technical hint: The main difference between CV and CC SMPS, for the same maximum output wattage, is in the design of their output part as it follows. Transformer output coil: CV -> thick wire, small number of turns. CC -> thin wire, large number of turns. Output sensor: CV -> it feedbacks a signal related to output voltage CC -> it feedbacks a signal related to output current Autolight, Kerim Fahme 7:56 PM 4/5/2008