LED Driver with Overcurrent Protection
Per The Photon's comment, you might find something like this simpler







simulate this circuit &ndash; Schematic created using CircuitLab

where R3 and R2 are chosen to give the desired current at the maximum input voltage which your colleagues can produce. This, of course, means that you'll have to supply a higher input voltage to produce the same current level, but that may or may not be a problem. Certainly, providing voltages as low as you do seems a bit unusual.