Lighting is now generally popular with LEDs . To do this, you must understand the LED's operating conditions, operating principles, driving methods and typical applications to maximize the application of LED lighting.
2 LED working principle
To design a driver circuit, you must first master its working principle. The brightness of the LED is mainly related to VF and IF. The volt-ampere characteristics of the LED are shown in Figure 1, where VF is the forward voltage drop of the LED and IF is the forward current. When the forward voltage exceeds the threshold (ie, the turn-on voltage, as shown in Figure 1.7V), it can be approximated that IF is proportional to VF. As can be seen from the figure, the highest IF of the LED can reach 1A, and the VF is usually 2 V to 4V.
Figure 1 LED's relationship between VF and IF
The forward voltage drop of the LED varies widely (up to 1V or more), and the VF-IF curve in the above figure shows that a small change in VF causes a large change in IF, which causes a large change in brightness. Therefore, usually the luminescence properties of LEDs are described by a function of current, not as a function of voltage. However, the output voltage of the general rectifier circuit also changes with the fluctuation of the grid voltage. It can be seen that the constant voltage source driving cannot ensure the consistency of the LED brightness and affect the characteristics of the LED. Therefore, LED drivers are usually driven by a constant current source.
Multi language: English/Spanish/Russia/Inter.char.set-..
1)High Brightness, user can change the advertising words whatever you want, easy and convenient in operation, more attactive compared with traditional banner.
2) The led moving sign display supports many kinds of languages and characters.
3) A lot of lively animation icons are built-in. 50 and more action effects for user option; Different brightness can be adjusted in software.
4) Time clock format, support date, countdown and any other odditional functions like temperature and humidity. Voltage input: 220v or110v.
5) led moving sign display Structure: well appreance frame, professional pendents, standard connectors and other accessories.
Service propaganda in finances, post offices, telecom, commerce, hospitals, sports stadiums
Policies and decrees issued from government organizations
Instructions, guidance and information issuance in airports and railways
1. Preeminent effects: Clear and stable pictures without distortion and disturbance.
2. High quality: adopting first-class chips and wafers imported from abroad
3. Flexible form: continuity, overlying, combination of dynamic and static playing, various effects include rolling moving, typewriting, gradual changing and so on
4. off-line running function: adopting the monolithic design technology and computer string communication way, which can operate in off-line state setting the dates and revising a data via the telephone line
1.Your inquiry related to our products or price will be replied in 24hrs
2.OEM&ODM,any your customized lightings we can help you to design and put into product
3.Protection of your sales area,ideas of design and all your private information
4.Top Quality+Reasonable Price+Responsible After Service=Successful & Win
5.Produce all kinds of Pitch: P4.75, P7.62, P10, P12, P16, P20, P25, P31.25...
Outdoor Single Color Led Display,Led Display Board,Outdoor Led Display Screen,Single Color Led Moving Display
Shenzhen Joy LED Display Co., Ltd. , https://www.joe-led.com