| 摘要 |
<p>The present invention relates to a power supply for an LED lighting device. The power supply for an LED lighting device includes a rectifier which rectifies AC power to output DC power; a buck-boost converter which smoothes and increases or reduces a voltage corresponding to the DC power to output DC power having a predetermined voltage and current to the LED lighting device; an LED drive controller which outputs an on or off switching signal to a switch of the buck-boost converter to control an output of the buck-boost converter with a predetermined DC voltage and current; a voltage sensor which senses a voltage input to the buck-boost converter; and a dimming signal input unit which feeds back a dimming signal corresponding to the sensed voltage to a dimming port of the LED drive controller when the sensed voltage from the voltage sensor is included in a preset reference level range. The LED drive controller controls a duty rate of a switching signal according to a voltage corresponding to power input to the dimming port to linearly control the output of the buck-boost converter. Accordingly, a DC/DC converter is configured instead of using an electrolytic capacitor in the power supply for an LED lighting device using a step-down (buck type) or step-up (boost type) converter to maximize the service life. A level of an input voltage is fed back to be used as an input of the dimming port so that an operation range extends. Thus, the LED lighting device may operate at a low input voltage to improve power efficiency.</p> |
