Patent ID: 8901836
Filing Date: 2014-12-02
Classification: H05B,Y02B

Abstract:
1. A dimming controlling circuit for LED, comprising: a switch configured to connect a main circuit and a power grid; a switch-on duration controlling circuit configured to output a switch-on duration controlling signal according to action times of the switch; a switch-off controlling circuit configured to compare a voltage of the switch-on duration controlling signal and a voltage of a signal from a terminal of a switch transistor in the main circuit to obtain a comparison result and to output a switch-off controlling signal according to the comparison result; a switch-on controlling circuit configured to generate a switch-on controlling signal after a first preset duration since receiving the switch-off controlling signal; and a logic unit configured to output a switch transistor controlling signal according to the switch-off controlling signal and the switch-on controlling signal, wherein the switch-on duration controlling circuit comprises: a selecting circuit configured to select a voltage corresponding to the switch-on duration controlling signal according to the decoding result.