Bus bar current control circuit, constant-current driving controller and LED light source

摘要

The present invention relates to a busbar current control circuit, a constant current drive controller and an LED light source, wherein the busbar current control circuit comprises a branch resistor, a branch capacitor and a branch current source, the branch resistor and the branch capacitor are connected in parallel to form a branch, one end of the branch is connected a position between the busbar resistor and the load, and the other end is connect to the branch current source; the branch current source outputs to the branch a current of adjustable magnitude, the sum of the voltage on the busbar resistor and the voltage on the branch resistor remains constant. Wherein the branch resistor occupies a portion of the voltage of the busbar resistor so that the magnitude of the current output by the busbar changes continuously, that is, when the current flowing into the branch increases, the voltage occupied by the branch resistor increases and the voltage on the busbar resistor decreases, so as to reduce the current on the busbar. Since the branch current is smoothly adjusted by the branch current source, the regulation of the Output current on the busbar is also smooth. This avoids the use of the SPWM wave or the dimming switch circuit in the prior art, and the stroboscopic phenomenon due to the discontinuity of the driving current.