CPC H05B 45/325 (2020.01) [H05B 45/37 (2020.01); H05B 45/46 (2020.01)] | 20 Claims |
1. A light emitting diode (LED) control device comprising:
a power supply connected to a first driving node and a second driving node through which an LED driver is configured to supply power to an LED module which comprises a first LED string configured to output light of a first color temperature and a second LED string configured to output light of a second color temperature;
a square wave generator configured to operate based on a first internal power supply voltage output from the power supply and generate a square wave;
a duty ratio controller configured to output a control signal based on the square wave, and change a slope of the control signal based on a change in a time constant; and
a switch circuit configured to operate based on a second internal power supply voltage output from the power supply, and control a ratio of a first current applied to the first LED string and a second current applied to the second LED string based on a change in the slope of the control signal.
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