Detailed description of the functional characteristics of the LED explosion-proof lamp drive power supply

1. What is the driving power supply for LED explosion-proof lamps:

LED explosion-proof lamp drive power supply power supply is replaced by a specific voltage and current to drive the LED light-emitting converter, usually: LED explosion-proof lamp drive power input includes high-voltage power frequency AC (ie, mains), low-voltage DC, high voltage DC, low-voltage high-frequency AC (such as the output of electronic transformers). The output of the LED driver power supply is mostly a constant current source that can change the voltage as the LED forward voltage drop value changes. LED explosion-proof lamp power core components include switch controllers, inductors, switching components, feedback resistors, input filter components, output filters, and more. According to the requirements of different occasions, there are also input overvoltage protection circuit, input undervoltage protection circuit, LED open circuit protection, overcurrent protection and other circuits.

2, LED explosion-proof lamp drive power features:

(1) High reliability of LED explosion-proof lamps:

Especially like the driving power of LED street lights, installed at high altitude, maintenance is not convenient, and the cost of maintenance is also large.

(2) High efficiency of LED explosion-proof lamps:

LED explosion-proof lamps are energy-saving products that drive power supplies with high efficiency. It is important to dissipate heat from the power supply installed in the luminaire. The power supply has high efficiency, its power loss is small, and the heat generated in the lamp is small, which reduces the temperature rise of the lamp. It is effective for delaying the light decay of LEDs.

(3) High power factor of LED explosion-proof lamp:

The power factor is the grid's load requirements. Generally, there are no mandatory indicators for electrical appliances below 70 watts. Although the power factor of a single power consumer with low power has little effect on the power grid, the amount of lighting used at night is large, and the similar load is too concentrated, which will cause serious pollution to the power grid. For 30 watts to 40 watts of LED driver power, it is said that in the near future, there may be certain indicators for power factors.

(4) Driving mode of LED explosion-proof lamp:

There are two types of traffic: one is a constant voltage source for multiple constant current sources, and each constant current source supplies power to each LED separately. In this way, the combination is flexible, and all the LED faults do 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 mode adopted by “Zhongke Huibao”. LEDs are operated in series or in parallel. Its advantage is that the cost is lower, but the flexibility is poor, and it is necessary to solve a certain LED failure without affecting the operation of other LEDs. These two forms coexist for a while. Multi-channel constant current output power supply mode will be better in terms of cost and performance. Perhaps it is the mainstream direction in the future.

(5) Surge protection of LED explosion-proof lamps:

The anti-surge capability of LED explosion-proof lamps is relatively poor, especially against reverse voltage capability. It is also important to strengthen protection in this area. Some LED lights are installed outdoors, such as LED street lights. Due to the start of the grid load and the induction of lightning strikes, various surges will be invaded from the grid system, and some surges will cause LED damage. Therefore, the analysis of the "Zhongke Huibao" drive power supply should have a certain lack of surge protection, and as the power supply and lamps are frequently replaced, the LED drive power supply should have the ability to suppress the intrusion of surges and protect the LED from damage.

(6) Protection function of LED explosion-proof lamp:

In addition to the conventional protection function, the power supply increases the LED temperature negative feedback in the constant current output to prevent the LED temperature from being too high; it must meet the safety and electromagnetic compatibility requirements.

3. The power supply of LED explosion-proof lamps is classified according to the driving method:

(1) Constant current type

Within the circumference, the load resistance is small, the output voltage is low, and the load resistance is larger, the output voltage is higher;

The constant current circuit is not afraid of load short circuit, but it is forbidden to completely open the load;

The constant current drive circuit is ideal for driving LEDs, but it is relatively expensive; it should be noted that the maximum current and voltage values ​​used limit the number of LEDs used.

(2) Voltage regulator

When the parameters in the voltage stabilizing circuit are determined, the output voltage is fixed, and the output current changes as the load increases or decreases;

The voltage regulator circuit is not afraid of the load open circuit, but it is forbidden to completely short the load;

Driving the LED with a voltage-stabilized driving circuit, each string needs to be added with a suitable resistor to make each string of LEDs display brightness average;

The brightness is affected by the rectified voltage changes.

4. The advantages and disadvantages of the overall constant current and the constant current working mode of the LED explosion-proof lamp:

Compared with the overall constant current, the constant current is more disadvantageous and the cost is higher. But it can really protect the LED and extend the life of the LED, so the constant current is the future trend.

5. Insufficient power supply for LED explosion-proof lamps:

LED drive lights are currently lacking in drive power:

The technicians of the company producing LED explosion-proof lamps and related products have insufficient understanding of the switching power supply, and the power supply can work normally. However, some critical evaluations and electromagnetic compatibility considerations are not enough, and there are certain hidden dangers;

Most of the power supply manufacturers of LED explosion-proof lamps are transformed from ordinary switching power supplies to do LED power supply, and the characteristics and usage of LEDs are not enough;

At present, there are almost no standards for LED explosion-proof lamps, most of which are standards for reference switching power supplies and electronic rectifiers;

Most of the LED explosion-proof lamps are not unified now, so most of them are relatively small. The purchase volume is small, the price is high, and the component suppliers are not very cooperative;

The stability of the power supply of the LED explosion-proof lamp: wide voltage input, high temperature and low temperature operation, over-temperature and over-voltage protection are not solved one by one;

The overall life of the drive circuit, especially for critical components such as the lifetime of the capacitor at high temperatures directly affects the life of the power supply.