An apparatus comprising: a source of electrical energy that generates an electrical voltage having a magnitude; an electric light; a switch that is responsive to a pulse width modulated signal having a duty cycle for selectively connecting the electric light to ground potential; and a controller that generates the pulse width modulated signal having the duty cycle to the switch; characterized in that the electric light is connected to a positive terminal of the source of electrical energy, the switch being connected between the electric light and ground potential, a resistive voltage divider being connected between the positive terminal of the source of electrical energy and ground potential so that the magnitude of the voltage that is applied to the controller input port is defined by the resistive voltage divider and is directly proportional to the magnitude of the output voltage of the source of electrical energy, and wherein the controller generates the pulse width modulated signal having a duty cycle to the switch in such a manner as to maintain an intensity of light emitted from the electric light relatively constant over at least a voltage variation of six volts to sixteen volts without exceeding the corresponding maximum LED current regardless of variations in the magnitude of the electrical voltage generated from the source of electrical energy by maintaining the duty cycle of the pulse width modulated signal constant whenever the voltage generated by the source of electrical energy is less than a threshold value, then decreasing the duty cycle of the pulse width modulated signal either linearly or non-linearly whenever the voltage generated by the source of electrical energy increases past the threshold value, the threshold value being about 14 V. a source of electrical energy that generates an electrical voltage having a magnitude; an electric light; a switch that is responsive to a pulse width modulated signal having a duty cycle for selectively connecting the electric light to ground potential; and a controller that generates the pulse width modulated signal having the duty cycle to the switch; characterized in that the electric light is connected to a positive terminal of the source of electrical energy, the switch being connected between the electric light and ground potential, a resistive voltage divider being connected between the positive terminal of the source of electrical energy and ground potential so that the magnitude of the voltage that is applied to the controller input port is defined by the resistive voltage divider and is directly proportional to the magnitude of the output voltage of the source of electrical energy, and wherein the controller generates the pulse width modulated signal having a duty cycle to the switch in such a manner as to maintain an intensity of light emitted from the electric light relatively constant over at least a voltage variation of six volts to sixteen volts without exceeding the corresponding maximum LED current regardless of variations in the magnitude of the electrical voltage generated from the source of electrical energy by maintaining the duty cycle of the pulse width modulated signal constant whenever the voltage generated by the source of electrical energy is less than a threshold value, then decreasing the duty cycle of the pulse width modulated signal either linearly or non-linearly whenever the voltage generated by the source of electrical energy increases past the threshold value, the threshold value being about 14 V.