| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus for controlling an LED string which can perform higher electricity efficiency and be manufactured with low cost by simplifying a layout process and further in which flicker can be reduced.SOLUTION: An apparatus for controlling an LED string utilizes series connection coupling between high voltage N-channel parts HV1-HV5 and low voltage current limit switch 21-25, 31-34, 41-44 units to detect a voltage or a current on a route. Therefore, when the voltage or the current is greater than a preset value, switching to low voltage current limit parts is performed, the high voltage N-channel parts HV1-HV5 are indirectly controlled, the low voltage current limit switch 21-25, 31-34, 41-44 unit closest to a ground terminal is turned on and the other current limit switch units are turned off. Thus, effects of controlling a high voltage LED are achieved. |
