| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ballast circuit for lighting an LED of high efficiency by assuring reliability of the LED which is sensitive to an electrical shock. <P>SOLUTION: The ballast circuit for lighting an LED includes: current limiting means which consists of a capacitor and a resistor that are connected in parallel so as to adjust the current used by the LED by charging/discharging at 60 Hz of an AC power supply; and a bridge diode which rectifies an AC voltage that has come through the current limiting means to a DC voltage. A capacitor and a resistor are connected in series between both ends of the bridge diode. At the positive terminal of the bridge diode, a silicon control rectifier is connected in parallel to the resistor and the capacitor connected in series, to constitute a surge up server circuit for protecting the LED from the surge which is generated at turning on/off of power supply. An LED array in which a plurality of forward LEDs are connected in series is connected to the output end of the surge up server circuit. An LED array in which a plurality of reverse LEDs are connected in series is connected to the negative terminal of the bridge diode. <P>COPYRIGHT: (C)2013,JPO&INPIT |
