DUAL MODE OPERATION LIGHT-EMITTING DIODE LIGHTING DEVICE HAVING MULTIPLE DRIVING STAGES

摘要

An LED lighting device includes first and second luminescent units, first and second current controllers, a line voltage sensing unit and a mode control unit. The first current controller with a first current setting is selectively coupled to the first luminescent unit according to a sensing voltage associated a range of the rectified AC voltage. The second current controller with a second current setting is coupled in series to the second luminescent unit . The line voltage sensing unit is configured to detect the sensing voltage. The mode control unit is configured to operate the LED lighting device in a first driving mode when detecting that the rectified AC voltage is within a first AC range and operate the LED lighting device in a second driving mode when detecting that the rectified AC voltage is within a second AC range.

主权项

1. A light-emitting diode (LED) lighting device having multiple driving stages and providing automatic mode switching, comprising:
a first luminescent unit driven by a rectified alternative-current (AC) voltage and comprising a plurality of luminescent devices coupled in series; a second luminescent unit driven by the rectified AC voltage and comprising a plurality of luminescent devices coupled in series; a first current controller selectively coupled in series to the first luminescent unit according to a sensing voltage associated a range of the rectified AC voltage and configured to provide a first current setting; a second current controller coupled in series to the second luminescent unit and configured to provide a second current setting; a line voltage sensing unit configured to detect the sensing voltage; and a mode control unit configured to:
operate the LED lighting device in a first driving mode when the sensing voltage indicates that the rectified AC voltage is within a first AC range by coupling the first current controller to the first luminescent unit and allowing the first luminescent unit and the second luminescent unit to be coupled in parallel with each other;operate the LED lighting device in a second driving mode when the sensing voltage indicates that the rectified AC voltage is within a second AC range by isolating the first current controller from the first luminescent unit and allowing the first luminescent unit and the second luminescent unit to be coupled in series to each other, wherein:
the first current controller is configured to regulate first current flowing through the first luminescent unit so that the first current does not exceed the first current setting and the second current controller is configured to regulate second current flowing through the second luminescent unit so the second current does not exceed the second current setting when the LED lighting device operates in the first driving mode; andthe first current controller is turned off and the second current controller is configured to regulate third current flowing through the first luminescent unit and the second luminescent unit so that the third current does not exceed the second current setting when the LED lighting device operates in the second driving mode.