Comparison of neon lights and LEDs in decorative lighting

1. Introduction

In recent years, with the continuous discovery and application of new materials and new processes, the luminous intensity of light-emitting diodes has been greatly improved, and the luminous efficiency has also exceeded that of incandescent lamps. With the continuous improvement of LED brightness, especially the emergence of ultra-high brightness LEDs, its application field has been further broadened, from the traditional use as instrument signal indicators to the development of traffic lights, car lights, indoor and outdoor decorative lighting, mobile phone backlights, display screens and other fields, and is deepening into the general lighting field. As part of the field of semiconductor lighting, neon lamps for urban landscape lighting and indoor and outdoor decorative lighting will gradually be replaced by LED lamps that are energy-saving, environmentally friendly, have a long life, high reliability and can achieve full-color changes. At present, various types of lamps made of LED in the field of decorative lighting are being gradually promoted, and it is expected that they will form a separate industry in the near future.

2. Full-color LED decorative lighting system architecture

A large square, stage, landmark building or large indoor full-color LED decorative lighting system is generally controlled by a microcomputer, which transmits control signals to multiple full-color LED decorative lighting standard subsystems (a standard subsystem consists of a single-chip control/drive module and multiple full-color LED lamps) through the microcomputer, and drives each group of LED lamps through the subsystem single-chip control/drive module. By making different settings with software on the microcomputer, the entire decorative lighting system can achieve the expected lighting effect or display different text or patterns. The structural diagram of a large full-color LED decorative lighting system is shown in Figure 1 below.

1. Structure of standard subsystem

The structure of a standard full-color LED decorative lighting subsystem is shown in the dotted box in Figure 1. It is composed of a standard control/drive module and multiple LED lamps that can achieve full-color changes. It can be used as a small decorative lighting system for small decorative lighting places alone, or it can be combined with multiple standard subsystems and controlled by a central controller to form a large decorative lighting source system suitable for different places, displaying expected graphics or texts and achieving full-color changes. The structural block diagram of the full-color LED decorative lighting standard subsystem is shown in Figure 2 below.

It can be seen that it mainly consists of the following parts:

(1)CPU control module

It mainly consists of a CPU microprocessor, a standard communication interface with the host computer, a standard communication interface with the display driver module and an ambient light intensity detection module to form a standard control module hardware structure. By compiling different software, it can be used in different places.

CPU microprocessor: 51 series single-chip microcomputer can be used as microcontroller. The microcontroller can be connected to the host computer through a standard communication interface to receive and process the control signals and data sent by the host computer. It can also use the control program and data stored in the microcontroller to send control signals and data to the LED lamp driver module through the data output line.

Ambient light intensity detection module: This module mainly transmits the detected ambient light intensity data to the microcontroller, and the microcontroller automatically adjusts the luminous intensity of the lamp according to the ambient light intensity.

Interface with host computer (microcomputer) and display driver module: standard RS232, RS422AK or RS485 communication interface can be used.

(2) Display driver module

The display driver module group is composed of multiple standard full-color LED lamp driver modules with the same structure. Each standard driver module drives a full-color LED lamp. The number of driver modules required is determined according to the number of LED lamps required for different use occasions of the subsystem. Each standard driver module receives the control signal and R/G/B color change signal sent by the microcontroller through a standard interface, and after processing, drives the full-color LED lamp to display the set state and color through a standard interface (which can be made into a standard four-core interface, including three G/G/B drive lines and one common power line).

(3) AC/DC power conversion module

It mainly provides working power for the entire control subsystem and for driving multiple full-color LED lamps. This module can be made into standard modules of different power sizes like a switching power supply. This module needs to have a high power conversion efficiency to ensure a good energy-saving effect.

(4) LED lamps composed of R/G/B three-primary color LEDs that can achieve full color changes.

Each full-color LED lamp is connected to the driver module through a standard interface and connecting wires. The LED lamp is composed of several groups of light-emitting units, each of which contains a red LED, a green LED, and a blue LED. By arranging the light-emitting units reasonably, full-color changes can be achieved. According to different usage occasions, different numbers and structures of LED lamps can be selected.

2. Working Principle

Through the control program built into the microcontroller, the microcontroller sends control signals and data to the full-color LED lamp driver module. The driver module generates corresponding actions according to the requirements of the control signals and data, thereby realizing individual control of each full-color LED lamp composed of three primary colors of R, G, and B. If the microcontroller continuously sends control signals and data to each LED display driver module, so that each LED lamp is continuously coordinated and controlled, the overall lighting can produce a variety of colors and a variety of dynamic display effects.

A large-scale urban lighting, indoor and outdoor decorative lighting and landscape lighting project or large-scale advertising display system can adopt a combination of multiple standard full-color LED decorative lighting subsystems. Each standard subsystem is connected to the host computer (microcomputer) through a standard communication interface to form a large system. Different display programs are edited on the microcomputer using relevant software and transmitted to each subsystem through signal lines. Each subsystem can work according to the prescribed program, so that the entire large system can display the predetermined graphics, text and color.

3. Application prospects of full-color LED decorative lighting system

With the continuous development of my country's economy and the improvement of people's material quality of life, people have higher and higher requirements for the environment of the city where they live, "greenery is needed during the day and lights are needed at night". In particular, the landscape lighting of the city at night has become an important part. The lighting of the city at night has evolved from the early simple lighting to the landscape lighting of the city at night. That is to say, the city lighting is evolving from lighting to colorful dynamic effects, and the brightness of the lights has become a beautiful landscape of the city at night.

The era feature of urban landscape lighting has greatly stimulated the lighting industry. People are making every effort to find new light sources that are energy-efficient, long-life, low-maintenance, environmentally friendly, pollution-free, and multi-color to replace traditional incandescent lamps and gas-filled light sources. This brings opportunities to LED light sources. As a semiconductor solid "cold" light source, LED has the characteristics of energy saving, environmental protection, long life, high reliability, and easy control, which just meets the above requirements. Various lighting fixtures made of LED have now entered the field of decorative lighting and gradually replaced the existing fluorescent lamps and incandescent lamps. This system takes advantage of the easy control and full-color change characteristics of LED. It is envisioned to form standardized and serialized products of lighting sources, lamps and control systems, and to conveniently combine various standard components according to different occasions to form the required full-color LED decorative lighting system. This system can be widely used in urban lighting and landscape lighting system engineering, large-scale advertising display systems, indoor and outdoor decorative lighting, and large-scale stage lighting systems, so it has broad market prospects. With the continuous advancement and development of LED technology, its product costs will become lower and lower, and the prices will become more and more competitive. LED decorative lighting sources and lamps will eventually replace the existing traditional decorative lighting fixtures and form an independent industry.

IV. Conclusion

Through the above analysis, we know that a large full-color LED decorative lighting system can be composed of several standard full-color LED subsystems, and each subsystem can be composed of a standard CPU control module, a standardized/serialized full-color LED lamp driver module, an AC/DC power conversion module and several full-color LED lamps of various structures/forms. Moreover, each module or component can be connected through a standard interface, so it is easy to achieve standardization and reduce costs. Moreover, various standard components can be conveniently used to form a large full-color LED decorative lighting system suitable for different places and displaying different texts or graphics. Therefore, it has broad market prospects.