Patent ID: 9615419
Date: 2017-04-04
CPC Classifications: H05B,Y02B

Claim:
1. An Alternating Current (AC) Light Emitting Diode (LED) driving circuit, comprising: a power supply unit including a dimmer connected to an AC power source and supplied with an AC voltage from the AC power source and a rectification circuit configured to rectify an output voltage of the dimmer; an LED driving unit including an LED lighting unit having a first LED unit located at a shortest distance from an output terminal of the rectification circuit to an n-th LED unit located at a longest distance from the output terminal of the rectification circuit, and a plurality of switching circuit units, input terminals of which are respectively connected to output terminals of a single LED unit, or two or more LED units constituting the LED lighting unit to form current supply channels for corresponding LED units; a dimmer driving unit including a voltage-controlled current source, an input terminal and an output terminal of which are respectively connected to a connection line between the output terminal of the rectification circuit and the first LED unit and to an output terminal of the switching circuit units, a reference voltage supply unit configured to apply a positive (+) reference voltage to the voltage-controlled current source, and a common resistor, a first end of which is connected to a negative (−) terminal of the reference voltage supply unit, and a second end of which is connected in common to an output line of the voltage-controlled current source and to an output terminal of the switching circuit units, wherein an output voltage of the voltage-controlled current source connected in series with the common resistor is input as a negative (−) voltage to the voltage-controlled current source, and then the current supplied from the rectification circuit to the LED driving unit is included in a negative feedback path of the dimmer driving unit.