Patent ID: 8866394

Claim:
A driving circuit for precise constant-current control of multiple LED branches, comprising: a high-frequency pulse Alternating Current (AC) source, and a circuit unit provided for the high-frequency pulse AC source, wherein, the circuit unit comprises a rectification and filtering circuit, a balancing capacitor and two LED loads; and the rectification and filtering circuit comprises two independent half-wave rectification circuits and two filter capacitors; each of the half-wave rectification circuits comprises two diodes connected in series, for supplying electric power to one of the LED loads; each of the LED loads is connected in parallel with one of the filter capacitors; the balancing capacitor is connected in series with an input terminal of the rectification and filtering circuit, wherein: the rectification and filtering circuit comprises a first diode, a second diode, a third diode, a fourth diode, a first filter capacitor and a second filter capacitor; the first input terminal of the rectification and filtering circuit is common to both an anode of the first diode and a cathode of the second diode, and the second input terminal of the rectification and filtering circuit is common to both an anode of the third diode and a cathode of the fourth diode; the balancing capacitor is connected in series with one of the input terminals of the rectification and filtering circuit; a positive terminal of a first LED load is connected with a cathode of the first diode, and a negative terminal of the first LED load is connected with an anode of the second diode; a positive terminal of a second LED load is connected with a cathode of the third diode, and a negative terminal of the second LED load is connected with an anode of the fourth diode; and the anode of the second diode is connected with the anode of the fourth diode or the cathode of the first diode is connected with the cathode of the third diode; the first and second filter capacitors are connected in parallel with the two LED loads respectively.