The difference between LED drive power supply and traditional power supply

LED driver power supply and traditional power supply in principle is not much different, but LED driver IC in order to meet the characteristics of LED lighting, integrated more functions, even with ordinary power drive IC can achieve those functions, but the circuit is more complicated. The driver IC of the LED has little to do with the circuit design scheme, it is only related to the total power that needs to drive the LED, that is, the IC has a maximum driving power, and if it exceeds this power, it will be replaced with another IC.

The applications of LED drive power supply are used for spotlights, cabinet lights, night lights, eye protection lights, LED ceiling lights, lamp cups, buried lights, underwater lights, wall washers, floodlights, street lights, signboard light boxes, string lights, downlights, special-shaped lights, star lights, barrier lights, rainbow lights, curtain wall lights, flexible lights, strip lights, strip lights, with lights, piranha lights, fluorescent lights, high pole lights, bridge lights, miner's lights, flashlights, emergency lights, desk lamps, lighting, traffic lights, energy-saving lights, car taillights, lawn lights, colored lights, crystal lights, grille lights, Suidao lights, etc.

What is LED drive power supply?

LED drive power supply converts the power supply into a specific voltage current to drive LED light-emitting voltage converter, usually: LED drive power input includes high voltage power frequency AC (i.e. mains), low voltage DC, high voltage DC, low voltage high frequency AC (such as the output of electronic transformers) and so on. Most of the output of the LED drive power supply is a constant current source that can change the voltage with the change of the forward voltage drop value of the LED. The core components of LED power supply include switching controllers, inductors, switching components (MOSfets), feedback resistors, input filter devices, output filter devices, and so on. According to the requirements of different occasions, there are also input overvoltage protection circuits, input undervoltage protection circuits, LED open circuit protection, overcurrent protection and other circuits.

2. Characteristics of LED drive power supply

(1) High reliability Especially like the drive power supply of LED street lights, installed at high altitude, maintenance is inconvenient, and the cost of maintenance is also large.

(2) High efficiency LED is an energy-saving product, and the efficiency of the drive power supply is high. It is important for the junction heat dissipation in which the power supply is installed in the luminaire. The efficiency of the power supply is high, its power consumption is small, and the heat generation in the lamp is small, which reduces the temperature rise of the lamp. It is beneficial to delay the light decay of LED.

(3) High power factor Power factor is the load requirement of the power grid. Generally, there are no mandatory indicators for electrical appliances below 70 watts. Although the power factor of a single consumer with little power is low, it has little impact on the power grid, but the amount of lighting used at night is large, and the similar load is too concentrated, which will cause more serious pollution to the power grid. For 30 watts ~ 40 watts LED drive power supply, it is said that in the near future, there may be certain index requirements in terms of power factors.

(4) Drive mode There are two kinds of common now: one is a constant voltage source for multiple constant current sources, and each constant current source separately supplies power to each LED. In this way, the combination is flexible, and the failure of one LED does not affect the work of other LEDs, but the cost will be slightly higher. The other is direct constant current power supply, which is the driving method adopted by "Zhongke Huibao", and the LEDs are operated in series or parallel. Its advantage is that the cost is a little lower, but the flexibility is poor, and it has to solve the problem of a certain LED failure and does not affect the operation of other LEDs. These two forms coexist for a period of time. The multi-channel constant current output power supply mode will be better in terms of cost and performance. Maybe it's the mainstream direction in the future.

(5) Surge protection The ability of LED to resist surges is relatively poor, especially the ability to resist reverse voltage. It was also important to strengthen protection in that regard. Some LED lights are installed outdoors, such as LED street lights. Due to the start-up of the grid load and the induction of lightning strikes, various surges are invaded from the grid system, and some surges will cause LED damage. Therefore, the analysis of the drive power supply of "Zhongke Huibao" should have certain deficiencies in surge protection, and as for the frequent replacement of power supplies and lamps, the LED drive power supply should have the ability to suppress the intrusion of surges and protect the LED from being damaged.

(6) Protection function In addition to the conventional protection function of the power supply, it is best to add LED temperature negative feedback in the constant current output to prevent the LED temperature from being too high; To meet the requirements of safety regulations and electromagnetic compatibility.

Common LED power supplies:

There are many types of LED power supplies, and the quality and price of various types of power supplies vary greatly, which is also one of the important factors affecting product quality and price. LED drive power supplies can usually be divided into three categories, one is the switching constant current source, the other is the linear IC power supply, and the third is the resistive capacitance step-down power supply.

The ordinary power supply is generally a linear power supply, linear power supply, refers to the power supply in the linear state of the control tube work.

LED drive power supply is widely used in industrial automation control, military equipment, scientific research equipment, LED lighting, industrial control equipment, communication equipment, power equipment, instrumentation, medical equipment, semiconductor refrigeration and heating, air purifiers, electronic refrigerators, LCD displays, LED lamps, communication equipment, audio-visual products, security monitoring, LED light strips, computer cases, digital products and instruments and other fields.