DynaOhm LED Driver: The DynaOhm, 4006, is an active device which functions as a dynamic resistor, changing its value to maintain a constant current flow. Unlike a fixed resistor which will provide the proper current at a single voltage, the DynaOhm will maintain a fixed current over a wide voltage range. The DynaOhm was designed for use with low current LEDs (5mm, 30 mA) where the expense and size of a switching regulator cannot be justified.