It is a common misconception that the number of LEDs that
can be driven is dependent on the maximum Vt (threshold
voltage) given in the LED datasheets. This is not true in
practice because when the LEOs reach their operating
temperatures, the Vtfalls significantly [13]. Thus the typical VI
given in the datasheet can be reliably used .. Therefore a fixed
24V supply can reliably drive 7 LEOs and a 36V supply 10
LEOs, even if there is some voltage drop across the LED
driver.