1. Do You Know About POT Bobbin?? ? ? POT type bobbin?is generally used to make inductor?with high-power and main transformer, which is used together with POT type magnetic core. We are mainly making EE, EFD, EPC, ETD, PQ, POT, RM, UU, ROD and other Drum cores. It is?generally called?horizontal?bobbin, which has?the advantages of large wire-wrapping?space and convenient manufacture.?With so many features of the bobbin, its shape can vary greatly. As for the same type of bobbin, for example,?specific to such a fine classification, there are at least a dozen kinds of bobbin?of EE-19 vertical direct plug bakelite. It is mainly used in the production of switching power transformer, pulse transformer,?electronic ballast?and so on.?And it is applied in the fields of household appliances, lighting, communication, medical equipment and others. Transformer is a device by using the principle of electromagnetic induction to change the ac voltage. The main components are primary coil, secondary coil and iron core. The main functions of transformer are: voltage conversion, current conversion, impedance conversion, isolation, voltage stabilization (magnetic saturation transformer) and so on.TAKE POT3019A TYPE BOBBIN AS AN EXAMPLE:
1. Do You Know About POT Bobbin?
POT type bobbin is generally used to make inductor with high-power and main transformer, which is used together with POT type magnetic core. We are mainly making EE, EFD, EPC, ETD, PQ, POT, RM, UU, ROD and other Drum cores. It is generally called horizontal bobbin, which has the advantages of large wire-wrapping space and convenient manufacture. With so many features of the bobbin, its shape can vary greatly. As for the same type of bobbin, for example, specific to such a fine classification, there are at least a dozen kinds of bobbin of EE-19 vertical direct plug bakelite. It is mainly used in the production of switching power transformer, pulse transformer, electronic ballast and so on. And it is applied in the fields of household appliances, lighting, communication, medical equipment and others. Transformer is a device by using the principle of electromagnetic induction to change the ac voltage. The main components are primary coil, secondary coil and iron core. The main functions of transformer are: voltage conversion, current conversion, impedance conversion, isolation, voltage stabilization (magnetic saturation transformer) and so on.
TAKE POT3019A TYPE BOBBIN AS AN EXAMPLE:
(1) PIN NO. : 5:5P
(2) PIN PITCH: 5.0
(3) ROW PITCH: 28.5
(4) PIN DIAMETER: φ0.8
THE FOLLOWING IS A DATA TABLE ABOUT ALL THE SPECIFICATIONS OF POT TYPE BOBBIN,WHICH PROVIDED BY OUR FACTORY.
2. The wide application of LED in Beijing Olympic Games fully demonstrates the high-end application of LED and its good prospect
In Beijing Olympic Games and Paralympic Games, LED is ubiquitous and ubiquitous in all relevant occasions, from Olympic Village to Cultural Square, from citizen community to main news hall and broadcasting tower. The LED display products and lighting technology used in the Beijing Olympic Games are unprecedented in the history of the Olympic Games because of their large number, large scale, high technical level and wide application range.
In Beijing Olympic venues, a large number of LED displays with full color, high resolution and digitization as the dominant display devices are used for live broadcast, scoring display and various information services.
The LED display screen on the north and south sides of the National Stadium (Bird's Nest) has an area of 152 m2. It is the largest suspended display screen in the world. The LED display screen located on the west side of the National Swimming Center (Water Cube) is 152 m2. It provides live broadcasting, special effects playback and performance display for the audience. The proportion of the display screen is 4:3, and the resolution is 704*512. "Bird's Nest" and "Water Cube" full-color LED display are jointly constructed by Shenzhen Sansheng Technology Company and Japan Matsushita Company. The mantle LED of "Water Cube" is a curtain curtain full-color LED screen woven by Dalian Luming Group with 6.6 million self-developed ultra-high brightness display chips. All the core technologies involved in the electronic signal control system, virtual imaging technology and independent video source of this kind of daytime invisible and night display mantle LED have independent intellectual property rights.
The LED display screen of Beijing traffic information service is an important link of Beijing Olympic traffic security system, and it has become a beautiful scenic line of Beijing. On the eve of the Beijing Olympic Games, nearly 100 new LED variable intelligence boards were built on the main roads and areas of the Olympic traffic, bringing the total number of variable intelligence boards in Beijing to nearly 300. During the Beijing Olympic Games, inductor frequency response, inductor fan, inductor failure, inductor flux, 17 full-color LED display panels were installed on the Beijing Rail Transit Subway, enabling spectators to keep abreast of the Olympic Games at any time.
3. Characteristics and Technology of Magnetic Core for Poleless Lamp
The core of high frequency electrodeless lamp mostly uses Ni-Zn ferrite material. Because the so-called built-in electromagnetic generator designed in the middle position of the emitter is quite far from the activated phosphor, it is necessary to generate enough electromagnetic energy to activate the luminescence. This is the main reason why the frequency is as high as 2.65 MHz. However, the problems of electromagnetic radiation and radio frequency interference caused by 2.65MHz high frequency oscillation need to be dealt with technically. In order to shield the harmful electromagnetic pollution to human body and other equipments, the technology of vacuum coating tin oxide and aluminium film is used to treat the lamp chamber of the electromagnetic generator. This not only hinders the light transmission efficiency of the lamp, but also affects the light decay and service life of the lamp because of the high temperature of the lamp body. It also greatly increases the manufacturing efficiency. Ben, caused "Philip", "Oslan", "Panasonic" and other domestic and foreign lighting companies to implement this invention patent development of the main bottleneck!
The low-frequency electrodeless lamp works at low and medium frequencies with low manufacturing cost. Manganese-zinc ferrite cores are usually used. Its external structure is conducive to the development of high-power and ultra-high-power (200W-1000W) lamps and lanterns, so it is suitable for large and wide lighting areas. Its electromagnetic induction loop coil is tightly wrapped in the outer end of the luminescent body glass shell and is very close to the luminescent substance to be activated, so it does not need a lot of energy, that is, it does not need too high working oscillation frequency. Generally, 200-300 KHz can be easily generated enough to activate the electromagnetic induction ability of the phosphor in the luminescent body，inductor for sale, inductor frequency calculator, inductor failure modes, high efficiency. Compared with the oscillation frequency of about 200 KHz, the EMC and EMI processing methods are easy to reach the standard, and the manufacturing process is also much less difficult. Different people have different opinions, wise people have different opinions, both internal and external structures have their own advantages. At present, they coexist in the endless lamp industry. How to produce high-performance magnetic cores which can be used for both has become a difficult topic for magnetic material manufacturers.
The requirements for soft magnetic ferrite materials under these two working conditions are particularly stringent. It is necessary to have sufficient permeability at extremely low temperature [-40], start high frequency oscillation, and a fairly high Curie temperature [+280], in order to maintain non-stop oscillation, as well as to maintain high flux density and low power consumption in such a wide temperature range. This is a very big contradiction. Nickel-zinc material has the characteristics of high frequency and high Curie point, but low permeability at ultra-low temperature, which makes the coil inductance manganese-zinc material have the advantages of high magnetic density and low power consumption, but Curie point and frequency are difficult to ascend, high temperature is easy to stop vibration, and the specific volume of lamp is large.
4. Reasons for Transformer Screaming
1). Transformer impregnation: including no Varnish impregnated. The scream causes sharp waveforms, but the general carrying capacity is normal. This shows that the higher the output power, the worse the scream, and the lower the power, the less obvious the performance. I have had bad experience in overloading in a 72W charger product. It is found that there are strict requirements on the material of the magnetic core in this product. (The customer requirements of this product are more stringent.) Additionally, when the transformer is poorly designed, it is possible that the vibration will produce abnormal noise when the transformer is working.
2). PWM IC grounding wiring error: Usually some products can work normally, but some products can not be loaded and may not be able to start the failure, especially when some low-power IC is applied, it is more likely to not work properly. I have used SG6848 test board, because I did not have a thorough understanding of the performance of IC at the beginning, I was in a hurry on the basis of experience. Layout in a hurry. As a result, the wide voltage test can not be done.
3). Opto Coupler Operating Current Point Routing Error: When the Opto Coupler Operating Current Resistance is connected in front of the secondary filter capacitor, there is also the possibility of screaming, especially when the load is more.
4). Grounding wire fault of reference voltage regulator IC TL431: The same secondary reference voltage regulator IC grounding has similar requirements as the primary IC grounding, that is, it can not be directly connected with the transformer geothermally and coldly. If connected together, the consequence is that the carrying capacity decreases and the whistle and output power are positive ratio. When the output load is large and approaching the power limit of the power supply, inductor f, inductor f avis, inductor f biotechnology, the switching transformer may enter an unstable state: the duty cycle of the former cycle is too large, the conduction time is too long, and excessive energy is transmitted through the high frequency transformer; the energy of the energy storage inductance of DC rectifier is not fully released during this period, which is judged by PWM in the next period. There is no driving signal or too small duty cycle to turn on the switch tube; the switch tube is in the cut-off state in the whole cycle after that, or the turn-on time is too short; the energy storage inductance releases energy more than one whole cycle, the output voltage drops, and the duty cycle of the switch tube in the next cycle will be larger. This cycle causes the transformer to vibrate at a lower frequency (regular intermittent full cut-off period or frequency with drastic change in duty cycle) to produce a lower frequency sound that can be heard by the human ear. At the same time, the fluctuation of output voltage will also increase when the number of intermittent full-cut-off cycles per unit time reaches a considerable proportion of the total number of cycles, which will even reduce the vibration frequency of transformers originally operating in the supersonic band, enter the audible frequency range of human ears, and emit sharp high-frequency "whistle". Voltage transformer works in a serious overload state, there is always the possibility of burning out - this is the origin of "screaming" before many power sources burn down, I believe that some users have had similar experience.
5. Basic Composition of Switching Power Supply Control System
The control device is composed of various basic components with certain functions. The components of the system are classified according to their functions as follows:
Measurement Unit: Its function is to detect controlled physical quantities. This controlled quantity is usually the output voltage of the main power circuit and the input current of the main power circuit.
Given Unit: Its function is to give the parameters corresponding to the expected controlled quantity, biotech inductor f, biotechnologie inductor f, that is, given quantity. In switching power supply system, the given value is usually DC constant or AC sinusoidal value.
Comparing Unit: Its function is to compare the actual values of the detected controlled variables with the parameters, and to find out the deviation between them.
Correction Unit: Compensation Unit, which is connected in series or in parallel to improve the performance of the system. This compensation network is the core part of the control system and the key part to determine the performance of the control system. It can be realized by passive or active network composed of resistors and capacitors, or by digital devices such as MCU and DsP.