LED LUMINANCE ADJUSTMENT CIRCUIT

摘要

PROBLEM TO BE SOLVED: To prevent the deterioration of an LED by preventing a current exceeding the allowed maximum current set beforehand in a circuit for adjusting LED luminance by adjusting a drive current for the LED according to the input voltage.

SOLUTION: An LED luminance adjustment circuit comprises a voltage adjustment means 70 for setting voltage for setting the current value controlled by an LED drive current control means 30 and supplying voltage to this LED drive current control means and a maximum voltage control means 74 for restricting the voltage supplied by the voltage adjustment means to the voltage corresponding to the allowed maximum current value supplied to the LED by the LED drive current control means.

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