Constant-current LED power supply based on power factor compensation

The utility model discloses a constant-current LED power supply based on power factor compensation. A second capacitor (C2), a sixth diode (D6), and a third capacitor (C3) are sequentially connected in series and then are connected in parallel between two output ends of a rectifier bridge. The cathode of a fifth diode (D5) is connected with a common connection point of the anode of the sixth diode (D6) and the second capacitor (C2). The anode of the fifth diode (D5) is earthed. The anode of a seventh diode (D7) is connected with a common connection point of the cathode of the sixth diode (D6) amd the third capacitor (C3). The cathode of the seventh diode (D7) is connected with a positive electrode output of the rectifier bridge. A piezo-resistor (RV) and load LED lamps are sequentially connected in parallel between the two output ends of the rectifier bridge. According to the constant-current LED power supply, effective balance half-bridge compensation for the DC voltage output by the rectifier bridge can be carried out; the power factor of the power supply can be effectively improved; and the precision of the output current can be improved. When a transient surge voltage occurs, the resistance value of the piezo-resistor (RV) decreases rapidly, and the transient high voltage is absorbed by the piezo-resistor (RV), and thus the LED load is effectively protected.