In summary, constant output voltage supplies such as the LXV family may be used independently or with a driver IC to power a string of LEDs. Constant output current supplies maintain a fixed output current over a relatively wide range of load voltages. Dimming power supplies enable the adjustment of LED brightness by changing LED current. Typical dimming modes include PWM and/or use of a 0 ~ 10V_DC signal.  Both dimming modes are available in the LXD series. Environmental ratings are important. Even with indoor applications such as high bay lighting, IP66 or IP67 is sought for long term reliability against moisture ingress. LED supplies are typically rated for input voltages ranges of either 100 to 240V_AC, designated by type S, or 100 to 277V_AC, designated by type SW. While many LED supplies carry a 2 or 3 year warranty, all Advanced Energy LED power supplies carry a 5 year warranty.