Patent ID: 8513894
Filing Date: 2013-08-20
Classification: F21K,H05B,Y02B

Abstract:
1. A light emitting device controller circuit with dimming function adjustable by AC signal, comprising a controller which controls an operation of at least one power transistor to convert an input voltage to an output voltage to be supplied to a light emitting device, characterized in that the controller comprises a dimming circuit for controlling a current flowing through the light emitting device, the dimming circuit comprising: a signal conversion circuit receiving a phase-cut semi-sinusoidal signal having a turn ON angle and converting the signal to a DC signal; an average circuit obtaining an average of the DC signal level, the average being a function of the turn ON angle irrespective of amplitude of the phase-cut semi-sinusoidal signal having the turn ON angle, whereby different amplitudes with the same turn ON angle result in the same average; and a current control circuit for controlling the current flowing through the light emitting device according to the average of the DC signal level.