Patent ID: 9648682
Date: 2017-05-09
CPC Classifications: H05B,Y02B

Claim:
1. A current control circuit for a driving circuitry system of multi-stage light-emitting diode (LED) components coupled in series, the driving circuitry system comprising a rectifier and current modules, the rectifier performing full-wave rectification on an AC input to provide an output voltage to power the LED components, an input terminal of each current module being coupled to a cathode of the corresponding LED component to set a current flowing through the corresponding LED component, output terminals of the current modules being coupled together to form a common output terminal, and the current control circuit comprising: a first voltage-division circuit dividing the output voltage of the rectifier to obtain a first voltage; a first operational amplifier having a non-inverting input terminal receiving a reference voltage, an inverting input terminal coupled to the common output terminal, and an output terminal coupled to one terminal of a capacitor and a first input terminal of a multiplier; the multiplier having the first input terminal receiving an output voltage of the first operational amplifier, a second input terminal receiving the first voltage, and an output terminal providing a basis voltage for each of the current modules; the capacitor having the one terminal coupled to the output terminal of the first operational amplifier, and the other terminal coupled to a ground; and a resistor having one terminal coupled to the common output terminal and the other terminal coupled to the ground.