Method and apparatus for an L.E.D. flashlight

A flashlight, comprising:

• (a) a flashlight housing, the housing being suitable for at least one of receiving therein and mounting thereon at least one DC voltage source that includes at least one battery cell;
• (b) a light-emitting diode (LED) housing connected to the flashlight housing, the LED housing comprising one or more first LED units that each emit light and have a reflector for collimating the emitted light forwardly therefrom generally along an LED optical axis;
• and
• (c) a first electrical circuit that selectively applies power from the DC voltage source to the LED units, the first electrical circuit further comprising a control circuit for maintaining a predetermined light output level of the LED units as a charge on the battery cell varies;
• wherein the flashlight is of such compact size and low weight as to be suitable for single-handed portable operation by a user, the flashlight further having a purpose of providing general-purpose illumination.

A method of providing general-purpose illumination of such compact size and low weight as to be suitable for single-handed portable operation by a user, comprising the steps of:

• (a) providing one or more first LED units that each emit light and have a reflector for collimating the emitted light forwardly therefrom generally along an LED optical axis;
• (b) selectively applying power from a DC voltage source to the LED units;
• and
• (c) maintaining a predetermined light output level of the LED units as a charge on the DC voltage source varies by controlling the step (b).

A battery-powered portable flashlight (100) comprising:

• a casing (110) suitable to hold a battery;
• one or more light-emitting devices (LEDs) (150) mounted to the casing;
• a switch (140) mounted to the casing;
• and
• a control circuit (130) coupled to the battery, the LEDs, and the switch, wherein the control circuit drives the LEDs with electrical pulses at a frequency high enough that light produced by the LEDs has an appearance to a human user of being continuous rather than pulsed, and wherein the LEDs have proportion of on-time that increases as remaining battery power decreases.

An illumination source, comprising:

• (a) a light-emitting diode (LED) housing comprising one or more LEDs;
• (b) a source of electrical power;
• and
• (c) a control circuit that selectively applies power from a source of electric power to the one or more LEDs to substantially maintain a predetermined color spectrum of the one or more LEDs as a voltage of the source of electric power varies over a range that would otherwise vary the light output color spectrum.