Discussion on Problems and Solutions in Energy-saving Lamp Production

The production of energy-saving lamps in my country has developed rapidly, increasing at a rate of 30% to 40% per year. At present, its scale accounts for about 80% of the world's total. Unfortunately, there are still many problems in the production of energy-saving lamps in my country. my country can only be regarded as a large producer of energy-saving lamps, but not a strong one. According to the author's observations during his many years of work in energy-saving lamp production companies, there are mainly the following problems in the production of energy-saving lamps in my country:

(1) We do not have our own well-known brands that can occupy the world market. Some large domestic enterprises and companies basically do OEM production for foreign lighting companies or sales companies, and serve as their processing bases. They sell domestically or abroad under the brands designated by the other party, so that they not only occupy the domestic and foreign markets, but also grab a lot of profits, while domestic companies only earn a small amount of processing fees. This is undoubtedly making clothes for others, which is really a big problem that needs to be solved urgently. At the same time, in the domestic market, we do not have a well-known domestic energy-saving lamp brand that is familiar to the public, so when people choose energy-saving lamps, it is difficult to use some well-known energy-saving lamp brands as a reference like choosing other home appliances.

(2) At present, most of the circuits of energy-saving lamps adopt half-bridge inverter circuits and use magnetic ring transformers. However, it is very difficult for general engineering and technical personnel to fully understand and master the performance of magnetic rings. How to correctly select magnetic rings to achieve a good match with the inverter circuit, reduce the loss and heat in the circuit, and increase the life of the lamp is still a headache for many practitioners. Moreover, the testing and processing technology of magnetic rings is very cumbersome and takes a lot of manpower and working hours. In the context of the increasing shortage of labor in my country and the rising labor costs, the production cost of using magnetic rings is relatively high.

(3) Currently, companies producing energy-saving lamps lack suitable technical personnel. Existing university graduates either have a large gap between what they learned in school and the current production requirements, and cannot play the role they should in production or perform at the level they should, and are therefore abandoned by the company; or they automatically resign and seek other jobs due to salary issues or problems with their learning. It is difficult for companies to retain suitable technical personnel. The overall level of technical personnel in most existing small and medium-sized enterprises is not high enough. Many people have switched from the maintenance industry, and have accumulated knowledge and experience about energy-saving lamps based on their past half-baked electronic knowledge and experience, as well as their hard work at work. Some people have a high level of understanding and can solve some problems encountered in imitation and production, but they can only copy and imitate known samples. It is very difficult and unrealistic to rely on them to achieve product innovation.

(4) Due to the reasons mentioned in (2) and (3) above, the quality of energy-saving lamps varies greatly. The average life of poor-quality energy-saving lamps is very short and they will break down within a few months. This has caused residents who use energy-saving lamps to lose confidence and has created great resistance to the country's implementation of energy-saving and emission-reduction policies and the promotion of the use of energy-saving lamps.

2 Discussion on the solutions to the above problems

In order to solve the above problems, the author puts forward some immature views as follows.

2.1 An integrated circuit manufacturer produces an integrated chip with independent intellectual property rights.

This chip should have the following functions:

(1) It has RC self-oscillation, and the square wave generated by it drives the half-bridge inverter circuit, so that the half-bridge inverter circuit only has power driving function, but no self-oscillation function, eliminating the magnetic ring. In this way, the designer can easily set the oscillation frequency by changing the RC parameters, and its operating frequency can remain constant within the full input voltage range. Unlike the use of magnetic rings, the frequency is affected by voltage changes. When the voltage is high, the frequency decreases, the power increases, and the heat increases, making the circuit as a whole unreliable.

(2) It has a filament preheating function without power consumption. Through the internal circuit of the IC, the frequency changes in 3 stages (or 2 stages) at the beginning of operation, from high to low. When the filament preheating temperature is appropriate, the frequency is quickly swept from high to low to trigger and light the lamp. This method has a good preheating and protection effect on the filament, and does not consume power. It is easy to increase the life of the lamp by 1 time. For example, the life of the existing lamp without preheating can reach 5,000 hours, and it is not difficult to further increase its life to 10,000 hours with the preheating function. At present, energy-saving lamps rarely use preheating measures. Even if they are used, they use power-consuming PTC resistors, which not only increase the heat generation but also reduce the light efficiency. Moreover, this preheating method is closely related to the cold resistance of the filament, and often cannot achieve good preheating. The use of sweep frequency preheating method can eliminate the above disadvantages and achieve good preheating effect.

(3) It has an automatic zero voltage switch (ZVS) function, that is, when the voltage of the lower tube of the half-bridge is 0, the driving signal is added to the lower tube, and only then will the current appear, so as to reduce the loss. Otherwise, if the current appears when the voltage of the lower tube has not dropped to 0, the product of the voltage and current of the transistor collector will be very large, the power consumption will be very large, and the tube will be damaged due to overheating. The main reason why the existing circuit is unreliable is that it is difficult to achieve zero voltage switching by adjusting the component parameters when using magnetic rings (not to mention that some people may not be aware of this problem at all). By using IC circuits, by detecting the midpoint voltage of the half-bridge, it is easy to detect the non-zero voltage switching state, and the internal circuit of the IC circuit automatically eliminates it by adjusting the dead time between the conduction of the two tubes, which will greatly improve the quality of the lamp.

The quality and life of the lamp can be greatly improved by taking two measures: preheating and zero voltage switching.

(4) It has two switching tubes required for the half-bridge inverter circuit, and there is no need to connect two switching transistors to the external circuit. The circuit assembly can be greatly simplified, and the area occupied is greatly reduced, which is conducive to the miniaturization of energy-saving lamps. The circuit board of a low-wattage lamp can even be placed in the E27 lamp holder, which is very convenient for making candle lamps. The circuit of a compact fluorescent lamp is shown in Figure 1. It can be seen that this circuit is very simple. Except for the electrolytic capacitor C1 and the inductor L, all other components can be made of chip components. Using a not very complicated chip mounting machine and reflow soldering machine, a high-yield assembly line can be formed, which uses very little manpower and can produce energy-saving lamps with reliable quality and very consistent performance.

The use of IC chips will undoubtedly greatly improve the quality of existing energy-saving lamps.

Figure 1 Compact fluorescent lamp circuit

At present, the annual output of energy-saving lamps in my country is about 4 billion. If 1/3 of the lamps can use this chip, then the annual demand for this chip will be about 1 billion to 1.5 billion. With such an output, it should be no problem to reduce its cost to a level acceptable to energy-saving lamp manufacturers and consumers. At present, Philips, Fairchild, and IR have such chips, such as UBA2024, FAN7710, IR2520D, etc., but the price is relatively expensive and basically has not been widely promoted in the domestic market. As a major producer of energy-saving lamps, my country should have no technical problems in developing such chips with independent intellectual property rights; as long as the price is right and the product life is improved, there should be no problem in promoting it. In order to reduce costs, the author recommends making this chip into 3 grades, which can be divided into 5~11W, 13~18W, and 20~25W according to power, so that all low-power factor lamps can be covered for producers to choose according to their needs. With an output of 1.5 billion or more as a basis, it should be no problem to reduce the price.

2.2 Based on this chip, we can produce our own brand products.

In this way, both product quality and quantity can be greatly improved, Chinese manufacturing and Chinese brands can be integrated into one, and the unfavorable situation of domestic companies producing OEM products for foreign companies can be completely reversed.

2.3 The state should increase the implementation of energy efficiency standards for energy-saving lamps and introduce some effective policies to drive some non-energy-saving and short-life junk products out of the energy-saving lamp market as soon as possible, so that people can buy energy-saving lamps that they can trust. The state should also introduce some policies, adopt the method of combination and merger, and make the production of energy-saving lamps large-scale and intensive as soon as possible, so that some capable companies can become stronger and bigger, and like other home appliances, cultivate a number of well-known brands for consumers to choose. This issue is highly policy-oriented, but I believe that as long as the relevant departments take action, some practical solutions will always be found.

2.4 Establish majors related to the lighting industry in existing universities, colleges, higher vocational schools and technical schools, and cultivate technical talents for the lighting industry at all levels, especially in higher vocational and technical education, cultivate talents that energy-saving lamp manufacturers find suitable. The author has been engaged in secondary vocational and technical education in Nanjing Radio School (now restructured as Nanjing Information Vocational and Technical College) for many years. This is a school that attaches great importance to both basic theoretical knowledge education and practice, and its graduates have always been welcomed by employers. I think that in the lighting majors set up in higher vocational and technical education, the content of electronic circuits (including analog and digital circuits) courses should be strengthened to lay a certain foundation for familiarity with electronic ballast circuits and IC circuits; set up courses on the basic knowledge of gas discharge lamps and energy-saving lamps so that students can understand the performance and characteristics of lamps; in addition, courses on the use of components, computer drawing (using PROTEL software) and document writing should be set up. Schools should also attach importance to students' practical activities during their school years, so that they can be familiar with various circuits of ballasts, learn the skills of using oscilloscopes, especially storage oscilloscopes, so that their future debugging work is not based on intuition, but on quantitative basis, laying a certain foundation for their actual work in the factory. Since the price of instruments and equipment is now very cheap, the cost of setting up such a major and increasing practical links should not be too high. Graduates trained in this way will definitely be welcomed by employers, which can fundamentally change the current situation of lack of talent in energy-saving lamp production.

3 Conclusion

The above is my personal opinion on the development of my country's energy-saving lamp industry. It may be immature, but I would like to share my views here for reference by relevant departments.