Cost-effective LED lighting optimization design is very important

Indoor lighting LED lamps need to have a good cheap price, thus optimizing the product design is very important .

Based on worldwide supply grid voltage differences , LED lamps for mains voltage input into wide voltage input and constant voltage input two kinds ; common in different regions in order to grid voltage , wide input voltage of the LED lamps become mainstream products , wide voltage input LED lamps require the use of switching power supply constant current source , it is in the power network voltage changes from AC84-280V , relying on automatic buck switching power supply control and output a constant DC current. LED lamp must be operated in a constant current environment to function properly and efficiently emit light without flash.

LED constant current power supply switch

Switching constant current source power supply is to rely on the local switching frequency and voltage transformers to automatically lift , coping voltage fluctuations , the output constant DC current to the LED lamp beads make normal light .

Grid current into the LED drive power , the preferred treatment through the EMC , the bridge rectifier , the AC into DC ; followed by the power control chip and transformers , high-voltage direct-current voltage drops low loss LED lamp beads required operating voltage, and output constant operating current ; With a suitable voltage to meet the LED light bead of VF IF constant voltage and current requirements , LED lamp beads can be normal light.

However , the grid voltage is 50Hz or 60Hz frequency alternating current , the voltage waveform is a sine wave , so the rich get is rectified after 50Hz frequency and its harmonics pulsating DC ripple , ripple residual AC component that must be approved electrolytic capacitor filtering , energy storage , after the charge and discharge , in order to obtain relatively smooth direct current.


Switching constant current source , the main chip control IC requires no power supply ripple clean , you need to work the circuit ripple excluded , requiring bypass filter capacitor . By switching constant current power supply circuit in the transformer output LED drive current into direct current through the diode rectifier is simple , and therefore contains a lot of ripple , low ripple will produce the human eye can see a flashing , you must use electrolytic capacitors will ripple filter net .