| 摘要 |
A universal AC-line input light emitting diode (LED) drive includes a rectifier, at least one LED connected to one output of the rectifier, a controllable element in series with the at least one LED, and a circuit for turning off the controllable element when the line voltage exceeds a reference voltage. The reference voltage is selected to produce the average current through the LEDs when the line voltage is nominally 120VAC, 240VAC, or 277VAC. Another circuit may also be provided for switching the reference voltage between at least two levels (e.g., two of 120VAC, 240VAC, or 277VAC) when an average line voltage exceeds a certain level. |
