| 摘要 |
According to the present invention, there is provided a power supply circuit having an afterglow elimination function for an LED light, which is capable of eliminating afterglow of the LED light, where a lighting-off denoting lamp type power switch (30) is circuit-connected to a power supply line (20), or a general power switch (40) is circuit-connected to a common ground line (21) such that the afterglow generated from an LED lamp (150) when each power switch (30, 40) is switched off is prevented from being generated. According to the present invention, a power supply circuit includes: a converter circuit (110) for converting commercial power into driving power which is used to driving the LED lamp (150); a voltage divider resistor part (120) including first and second resistors (R1, R2) connected in series to an output terminal of the converter circuit (110) to form a voltage dividing ratio to an output voltage of the converter circuit (110); a first switching device (130) circuit-connected to an output terminal of the voltage divider resistor part (120) to apply an output voltage of the second resistor (R2) to the output terminal of the voltage divider resistor part (120), wherein the first switching device (130) is switched on when the output voltage of the second resistor (R2) is higher than a break-over voltage (break-down voltage) and is switched off when the output voltage of the second resistor (R2) is lower than the break-over voltage; and a second switching device (140) circuit-connected between an output terminal of the LED lamp (150) circuit-connected to an output terminal of the voltage divider resistor part (120) and the first switching device (130) to be triggered when the first switching device (130) is switched on so that the circuit is turned on, wherein the second switching device (140) cuts off the circuit when an input of the driving power source is cut off. |
