Neon electronic transformer related knowledge

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

GW MB10F 0.8A 1000V rectifier bridge

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The neon lamp is a low-temperature cold cathode glow discharge light source. The neon lamp is characterized by a high starting voltage, operating voltage and small operating current. In the past, in various neon projects and installations, iron core leakage transformers were used to match neon tubes to solve this problem. Its advantages are high reliability and durability. The disadvantages are large size, high power consumption, low power factor, power frequency noise, and inconvenient multi-function display control.

After the emergence of the worldwide energy crisis in the 1970s, many companies were working on new energy-saving electric light sources (such as fluorescent electronic ballasts, neon electronic transformers, etc.). With the rapid development of semiconductor technology, various high-pressure and high-current power devices used as switching tubes have emerged, providing a prerequisite for the development of neon electronic transformers. China's research and production of neon electronic transformers began in the mid-to-late 1980s. At that time, neon electronic transformers were the first generation, and they had the following disadvantages:

1. Insufficient output power: The neon brightness of the electronic transformer is dark, the length of the load lamp is limited, and the density of the lamp is low, which cannot meet the demand of large neon billboards.

2. The display brightness is uneven: because the constant current characteristics are poor.

3, the process structure is not good: only appropriate waterproof and moisture-proof treatment, mainly suitable for indoor occasions, insufficient sealing can not be used in the open air.

4, electromagnetic interference is too large: can not meet EMC requirements.

Second, the improvement of neon electronic transformer

In the late 1990s, the neon market such as commercial advertisements further prospered, the market demand grew more strongly, the production technology of neon tubes was further improved, and the construction experience of neon lights projects was continuously summarized and improved. At the same time, the application of switching power supply related technologies became more mature. High-quality and low-cost electronic components continue to emerge, prompting more companies to research and develop and improve neon electronic transformers, improving the key technologies of neon electronic transformers (high-voltage insulation, heat dissipation, electromagnetic shielding and waterproofing), improving circuit reliability and extending The service life of neon electronic transformers is improved, and the performance of the improved neon electronic transformers is improved;

A. Raise the voltage and current required for starting and normal operation for neon lights.

B. It has perfect protection functions; such as open circuit (overload) protection, short circuit protection, overheating (overcurrent) protection, etc.

C. Compliance with relevant safety certifications: such as UL certification, CE certification, etc.

D. It has protection against moisture, rain and dust.

At present, the neon electronic transformer basically adopts a voltage feedback type half bridge inverter circuit.

Third, the second generation of neon electronic transformers

In addition to advertising lighting, the application range of neon lights has broad prospects in night lighting, art decoration, signal signs and stage lighting for buildings (such as buildings and road bridges). The development of semiconductor electronic technology, the use of new materials such as trichromatic phosphors, neon electronic transformers have also been further promoted. The broad prospects of the market have led more companies to invest more human and material resources to research and improve the performance of neon electronic transformers, especially the perfection of computer control technology, such as the promotion and application of colorful gradient scanning technology, to match the use of electronic transformers. There is a qualitative leap in performance: 1 reduce the start or shut down the inrush current 2 using soft switching (zero voltage / current switching - ZVS / ZCS) technology, APFC technology.

At present, the development direction of neon electronic transformers is 1 volume, miniaturization, light weight and high efficiency. 2 high power, large output current, high power factor. The following are popular in the market:
1, exchange sense series:

1 regular type, mainly output 6KV@20MA/30KHz, suitable for advertising signs.

2 minicomputer a load length of about 0.1-3m, divided into 0.1-1m, 0.1-2m, O. Three kinds of 1-3m, suitable for color change control such as advertising light box and city lighting.

2, AC non-inductive series: output DC pulse high voltage, can solve the problem of uneven brightness, but the polarization of the mercury-filled lamp tube, and now gradually reduce the use.

3, AC highlight / super bright series: (Ф 15mm 氖 tube or Ф 20mm 氖 tube load): The output is mainly 10KV/40mA (Ф20氖 tube), mainly used for commercial advertising and urban lighting, neon engineering contours.

4. DC (low voltage) series: The input is mainly DCC2V±10% and DC24V±10%, which is more suitable for interior decoration craft lamps.

5, multi-function type: by improving the neon electronic transformer control circuit, you can increase its various functions; sound and light control, self-flash type, dimming type, writing type, etc., with special person lamp can also achieve color change, roll Silk and other functions.

Introduction to the new neon electronic transformer

A. The circuit design of the small neon electronic transformer is considered from the following aspects:

1. The load of the lamp is not activated, or the vibration is stopped and the motor is automatically turned off.

2, short circuit automatic protection, power consumption is only about 1.5w.

3. Automatically adjust the power according to the length of the load lamp tube, reduce the output current when overloading, and realize the protection function. Therefore, it has the following advantages in installation and use:

1 low price, small size, low output voltage, short connecting leads, and low electromagnetic interference to the environment.

2 The requirement for insulation is reduced, which can reduce the occurrence of dangerous accidents such as high-pressure ignition, thereby improving safety.

More than 3 small machines can be used together to increase the density of the lamp and avoid the phenomenon of "dark and dark at both ends" caused by the constant current when the high frequency and high voltage are used.

4 It is easier to control such as colorful gradient scanning, so it is more suitable for lighting fences, color change, advertising outlines, etc. in the "city lighting" project.

B. The AC highlight/super bright series features high power, large output current and high power factor. In the circuit design, power factor boosting circuit, de-harmonic circuit and anti-electromagnetic interference (EMI) measures are added to reduce the pollution to the power grid and suppress the surge from the power grid. According to whether there is a large DC filter electrolytic capacitor in the rectifier circuit For two;

1 There is a large electrolytic capacitor in the power supply circuit. When the startup or shutdown is performed, the inrush current is large, and the scanning control may be out of synchronization, and the service life is limited.

2 There is no electrolytic capacitor in the power supply circuit. When the startup or shutdown is small, the impact current is small, the power is very high (0.95 or more), and the constant current characteristics are good. It is suitable for color gradient scanning and other occasions.

Fifth, the neon electronic transformer is actually designed and improved in several aspects.

l, to improve its frequency, generally using bipolar transistors, switching frequency up to tens of kilohertz, if using MOSEET, it can reach hundreds of kilohertz, on the one hand can reduce the energy storage components used such as: capacitors, inductors Or the volume of the transformer, on the other hand, can improve the luminous efficiency of the neon.

2. Using a composite circuit, two or three transistors are used in parallel, and multiple energy storage components are used together to increase its power, increase its output current, and increase its power factor. Such as 10 meters super bright machine; input power 150W/230W, output current 40mA/60mA, power factor 0.955;

3. The whole neon electronic transformer is filled with epoxy resin. After vacuuming and baking, it can be waterproof and suitable for indoor and outdoor use.

4, select electronic components, try to reduce components, design must consider a certain amount of margin, such as filter capacitor with 2 voltage 250V series, select 105 ° C type finished machine after sufficient time to filter after aging, thereby improving its reliability Sex and service life;

5. Select advanced PCB LAYQUT technology, use computer-aided design and control, simulate its simple structure and best working condition, add EMI filter circuit, remove harmonic circuit and shield grounding device in circuit, effectively reduce electromagnetic interference;