Patent ID: 10548187

Abstract:
In connection with a ground transportation vehicle light head (86) powered by a battery-based voltage source (20) supplying positive (76) and reference (i.e., ground) (78) voltages that define a voltage difference (22) applied across a number of multiple series-connected high-power light-emitting diodes (HP LEDs) (12) and current regulator circuitry (80) electrically connected to them, ultra-low dropout circuit techniques are disclosed for increasing a portion of the voltage difference available from the battery-based voltage source to forward bias and thereby maximize the number of the multiple series-connected HP LEDs emitting light by maintaining a low voltage drop (82) across the current regulator circuitry. By maintaining the low voltage drop and making available from the battery-based voltage source an increased portion of the voltage difference, at least one additional HP LED is capable of being forward biased to thereby maximize the number of multiple series-connected HP LEDs emitting light from the light head.