METHOD FOR CONTROLLING POWER SUPPLY OF LED SIGNAL LIGHT, IN WHICH OPTICAL OUTPUT IS UNIFORMLY MAINTAINED BY USING A REFERENCE OPTICAL INTENSITY SETTING UNIT

摘要

PURPOSE: A method for controlling the power supply of a light emitting diode(LED) signal light is provided to maintain the optical output uniform by uniformly maintaining the forward voltage supplied to the LED constantly. CONSTITUTION: A method for controlling the power supply of a light emitting diode(LED) signal light includes the steps of: detecting one or more LED forward voltage drop(Vf) when the direct current having a predetermined voltage stability is applied to the LED module(90) with passing through the reference voltage generator(30); comparing the optical output with the reference optical intensity setting unit(50) so as to maintain within 20% with respect to the 25% reference; and emitting the uniform optical intensity by applying the changed voltage to the LED module.