| 摘要 |
<p>PURPOSE: An LED driving device is provided to simplify the structure of a circuit and reduce the volume of a product by using a ripple suppression circuit. CONSTITUTION: An input power source is a constant-current source, and a load (140) is composed of multiple LEDs connected in parallel or series. A rectifier rectifies the input power. A switching mode power supply (SMPS) receives the rectified voltage and converts the voltage into a voltage for driving the load. The SMPS comprises a control unit (121), a transformer (122), a high frequency rectifier (123), and a smoothing unit (124). A ripple suppression circuit (RSC) suppresses the ripple current included in the driving voltage outputted from the SMPSS and provides a stable DC current to the load. [Reference numerals] (100) Power input unit; (130) Ripple suppression circuit unit; (131) Reference voltmeter; (132) Second error amplifier; (133) Maintenance circuit unit; (134) Second error amplifier; (135) Control circuit unit; (136) Current detecting unit; (140) Load device; (AA) Input power (constant voltage source)</p> |
