Patent ID: 7550932

Claim:
A control method for controlling a power-converting module that is coupled to a light-emitting component, comprising the steps of: a) comparing duration of a predetermined logic state of a pulsating input dim control signal with a reference time period; b) when the duration of the predetermined logic state of the pulsating input dim control signal is not longer than the reference time period, generating a modulator control signal that corresponds to a reference voltage amplified by a gain equal to an average value of the pulsating input dim control signal, generating a pulse-width-modulated control signal from the modulator control signal, and providing the pulse-width modulated control signal to the power-converting module, thereby enabling the power-converting module to generate a drive voltage for driving the light-emitting component to generate a brightness output that corresponds to the pulsating input dim control signal; and c) when the duration of the predetermined logic state of the pulsating input dim control signal is longer than the reference time period, disabling the power-converting module to turn off the light-emitting component.