LED drive power main technology development trend

As a new light source, the near LED power supply and drive circuit are different from the electronic ballast of the fluorescent lamp. The main function of the LED drive circuit is to convert the AC voltage into a DC voltage and simultaneously match the voltage and current of the LED. As the silicon integrated circuit power supply voltage drops linearly, the LED operating voltage is more and more in the optimal range of the power supply output voltage. Most of the low-voltage IC power supply technologies are also suitable for powering LEDs, especially high-power LEDs . . In addition, the LED power supply should also be able to take advantage of the economies of scale brought about by the gradual increase in the output of low-voltage IC power supplies.
First, the main technical overview of LED power supply and drive circuit
1) Voltage conversion technology
Power supply is an important part of the reliability and adaptability of LED light sources. At present, the mains electricity in China is 220V AC, and the LED light source is a semiconductor light source, which is usually powered by DC low voltage. This requires AC-DC conversion circuit in or outside of these lamps to adapt to the characteristics of LED current drive. At present, the power supply selection methods include switching power supply, high-frequency power supply, and capacitor rectification and rectification power supply. Various options are selected according to different requirements such as current stability, transient overshoot, and safety and reliability.
2) Life and cost of power supply and drive circuit
In terms of LED life, although the life of a single LED itself is as long as 100,000 hours, its application must be matched with a power conversion circuit. Therefore, the overall life of an LED lighting device must be considered from the optoelectronic integration application. However, for lighting LEDs, in order to meet the matching requirements, the life of the power supply and the drive circuit must exceed 100,000 hours, making it no longer a bottleneck factor for the LED lighting system. Considering long life and not increasing too much cost, the life and cost of power supply and drive circuit should not exceed one third of the total cost of lighting system. In the early stage of LED lighting products development, power supply must be balanced. The relationship between the life of the drive circuit and the cost.
3) Programmable technology for drivers
A notable feature of LEDs as light sources is their ability to maintain lumens efficiency even at low drive currents, while also for RGB polymorphs.
In the case of mixing light to form white light, by developing a digital RGB hybrid control system for LEDs, the user can adjust the brightness, color and color of the LEDs in a wide range, giving a new visual enjoyment. . In the urban landscape lighting application, the LED light source can be changed according to different modes under the control of the microprocessor, forming a dynamic effect of the night, which will reflect the uniqueness of the LED relative to other light sources. Competitive Advantage.
4) Efficiency of power supply and drive circuit
The LED power supply and the driving circuit must have a certain forward current output close to the constant current required for the LED, and have a high conversion efficiency. The electro-optical conversion efficiency is an important factor of the LED illumination, otherwise the LED will be lost. The advantage of energy saving, the current commercial switching power supply has an efficiency of about 80%. As a power source for LED lighting, its conversion efficiency still needs to be further improved.

Ac Controller

What is a wireless AC controller? What does it do?

Wireless AC controller is a kind of network device, such as the AC100/150 of Fengrunda, which can be used to centrally control and manage wireless aps. It is the core of a wireless network and is responsible for managing all wireless aps in the wireless network. AP management includes: delivering configuration, modifying related configuration parameters, RF intelligent management, and access security control.

Why use a wireless controller, and what exactly does it do?

In fact, the role of the wireless controller is to play a gateway function between the WLAN and the Internet (on the router), and the data from different access points are aggregated and accessed to the Internet. The role of an access point (AP) is to complete wireless access, and it can control user access through network flags.

The role of wireless controllers

1, Flexible networking mode and excellent scalability

The AP does not need to be directly connected to the AC, so that the AP can be deployed in any place that needs to be covered through the network, such as you deploy an AP in each employee's home, and then connect to the wireless controller inside the enterprise through the VPN, you can expand the wireless network of the enterprise to the family of each enterprise member.

2, intelligent RF management functions, automatic deployment and fault recovery

Through the dedicated RF management module, we can initially estimate the AP deployment according to the user's architectural design drawing, and can calculate the average bandwidth of the wireless terminal, the coverage between AP and AP in the actual debugging process.

3. Centralized network management

All the configuration of the wireless network can be completed by configuring the wireless controller. For example, enable, manage, and maintain all AP devices and mobile terminals, including all functions such as radio wave spectrum, wireless security, access authentication, mobile roaming, and access users.

4, powerful roaming function support

The wireless controller uses AP as the boundary combined with fast RF management system, which greatly reduces the connection time between wireless client and AP, and thus realizes the function of fast roaming.

5. Load balancing

AP and wireless controller systems can distribute wireless users or terminals to nearby aps within the coverage area of an AP, ensuring the number of each wireless terminal or the sum of AP bandwidth transmission or the upper limit of each wireless terminal bandwidth.

6, wireless terminal positioning, rapid fault location and intrusion detection

Wireless controllers can track and locate the location of wireless terminals, such as wirelessly connected computers, PDAs and Wi-Fi mobile phones.

7, powerful access and security policy control

At present, the wireless system supports authentication of 802.1, WEB authentication, MAC, SSID, VPN, etc., and supports various encryption modes such as WEP, WPA, WPA-PSK, WPA2, etc., and all configurations can be configured globally through the wireless controller.

8, Qos support

AP and wireless switching systems can limit the maximum bandwidth of a user's wireless connection within each user's privileges. For different IP services, the system can also define different QoS queues through the wireless switch module. For example, for wireless voice applications, SIP and RTP protocols can be set in the high queue, while common applications such as http and ftp can be set in the low queue.

The wireless controller AC is more advanced than the AP, plays the role of manager in the wireless network, and the wireless controller AC also acts as a client to complete a series of functions in the wired network (such as authentication, authentication, etc.). However, wireless controller AC is not a WLAN device specified in the 802.11 protocol family, but as a supplement to the protocol in specific applications, and its price far exceeds that of ordinary access point (AP) devices.

In small-scale wireless networks that use only a few aps, it is not economical to use expensive wireless controller AC equipment. However, if the number of wireless aps is large, more than 20 can be used AC controller.

Ac Controller,Gigabit Wlan Controller,Enterprise Ac Gateway,Wireless Ap Controller

Shenzhen MovingComm Technology Co., Ltd. , https://www.movingcommiot.com

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