LED drive power knowledge

LED power is also a supporting products, currently on the market of power supply quality is uneven, the following for entering the bank industry to provide some relevant knowledge of LED driving power supply.

1, what is the LED driving power supply
LED drive power to the power supply is converted to a particular voltage and current to drive the LED emitting voltage converters, typically: LED driving power supply input includes high voltage AC ( i.e. electricity), low-voltage DC, DC high voltage, low voltage high frequency AC ( such as electronic transformer output ). LED drive power output is mostly with the forward voltage drop of LED value changing voltage constant current source. LED power core element includes a switch controller, inductor, switch components ( MOSfet ), a feedback resistor, the input filter, output filter device etc.. According to different requirements, but also has input over voltage protection circuit, input undervoltage protection circuit, LED circuit protection, over-current protection circuit.

In 2, LED drive power characteristics
( 1) high reliability
Like LED lamp driving power, installed in the high altitude, inconvenient repair, repair costs are.
( 2) high efficiency
LED is energy-saving products, to high efficiency driving power supply. The power supply is installed in the light within the node radiation is very important. Power supply efficiency is high, its power dissipation is small, the lamp heat is small, it reduces the lamp temperature rise. To delay the LED lumen is favorable.
( 3) the high power factor
Power factor is the power to the load requirements. Generally below 70 watts of electrical appliances, not mandatory targets. Although the small power single electric power factor low point on the grid had little effect, but the use of a large amount of night lighting, similar load too concentration, will produce more serious pollution to power grid. For 30 watts to 40 watts LED drive power, said that the near future, perhaps will be on power factor has certain requirements.

4、Drive mode
The current has two kinds: one is a constant voltage source for a number of constant current source, each constant current source to separate each LED power supply. In this manner, flexible combination, a LED fault, does not affect the other LED's work, but the cost will be slightly. Another is the direct constant-current power supply is" Branch Hui Bao" replaced with a drive mode, LED series or parallel operation. Its advantages are low cost a little, but poor flexibility, but also solve a LED fault, does not affect the other LED operation problem. The two, for a period of time to coexist. A constant current output power supply mode, the cost and performance will be better. Maybe the next mainstream direction.

( 5) surge protection
LED anti surge capacity is relatively poor, especially anti reverse voltage capability. Strengthen the protection is very important. Some of the LED lamp is installed in the outdoor, such as LED road lamp. As a result of power grid load and flings and lightning induction, from the grid system may invade the various surge, some surge causes LED damage. So the analysis of" Branch Hui Bao" driving power in the surge protection should have certain shortcomings, and as to the power supply and lighting replaced frequently, LED driving power to suppress the surge intrusion protection, LED is not damaged the ability.

( 6) protection function
Supply in addition to conventional protection function, preferably in a constant current output to increase LED temperature negative feedback, to prevent the LED temperature is too high; to comply with the safety and electromagnetic compatibility requirements.