| 摘要 |
<p>PURPOSE: A switching mode power supply for an LED light is provided to implement a high power factor by controlling the capacity value of a smoothing condenser according to input voltage. CONSTITUTION: An electromagnetic noise filter (110) filters the conductive and irradiative electromagnetic noise. A rectifying circuit unit (120) converts the direct current of a power signal which is output from the electromagnetic noise filter into alternating current. An input voltage-sensing smoothing capacity control unit (130) controls the capacity value of a smoothing condenser according to input voltage. A switching regulator (200) produces a pulse width modulation (PWM) switching control signal according to a PWM method. A PWM switching control unit (140) provides an LED module unit with the switching-controlled voltage which is output from the input voltage-sensing smoothing capacity control unit. A constant current control unit (310) controls the current, which flows in the LED module unit, to be constant current. [Reference numerals] (110) Electromagnetic noise filter; (120) Rectifying circuit unit; (130) Input voltage-sensing smoothing capacity control unit; (140) PWM switching control unit; (190) LED module unit; (200) Switching regulator; (310) Constant current control unit; (350) Overvoltage control and discharge control unit; (370) Overvoltage control unit; (380) Discharge control unit; (AA) Power</p> |
