3-WAY LED BULB

1 . A lighting circuit for a light emitting diode (LED) bulb capable of operating at different light output levels depending on received AC power, the LED bulb comprising:

a first group of LEDs electrically connected together to emit light as a group;

a second group of LEDs electrically connected together to emit light as a group;

an AC/DC converter circuit electrically connected to the first group of LEDs and the second group of LEDs;

a detector circuit configured to detect received AC power; and

a selection circuit operable to cause the AC/DC converter circuit to provide current into one configuration of LEDs from the group of configurations of LEDs consisting of: the first group of LEDs only, the second group of LEDs only, and the first and second group of LEDs,

wherein the configuration of LEDs to provide current to is selected based on received AC power.

2 . The circuit of claim 1 , wherein the detector circuit includes an energization circuit that detects when a plurality of inputs to the circuit are active.

3 . The circuit of claim 1 , wherein the selection circuit includes of a pair of gain-setting circuits.

4 . The circuit of claim 3 , wherein each of the pair of gain-setting circuits includes a transistor in series with a current-sense resistor.

5 . The circuit of claim 1 , wherein the first group of LEDs and the second group of LEDs are connected in series.

6 . The circuit of claim 5 , wherein the AC/DC converter circuit includes a transistor in series with the first and second groups of LEDs.