1. What Do You Know About?EFD Type Bobbin?? ? ?Type of EFD bobbin is generally used in production of multiwinding transformer, which is matched with EFD type magnetic core. It is generally called horizontal bobbin. The conventional products are horizontal (4 + 4) and horizontal (5 + 5). EFD15 SMD bobbin can meet the requirements of mounting. The bobbin has the characteristics of ?convenient wire-wrapping and large wire-wrapping space. It is widely applied in all kinds of lighting, switching power supply and precise electronic equipment, etc. Our company was founded in August 2012. We have passed ISO9001:2008accreditations. We win the trust from every customer on the principle of “the best quality and the shortest delivery time”. We all staff adhering to the principle of “?Honesty, diligence, sharing and innovation”. Take EFD15D type bobbin as an? example:
1. What Do You Know About EFD Type Bobbin?
Type of EFD bobbin is generally used in production of multiwinding transformer, which is matched with EFD type magnetic core. It is generally called horizontal bobbin. The conventional products are horizontal (4 + 4) and horizontal (5 + 5). EFD15 SMD bobbin can meet the requirements of mounting. The bobbin has the characteristics of convenient wire-wrapping and large wire-wrapping space. It is widely applied in all kinds of lighting, switching power supply and precise electronic equipment, etc. Our company was founded in August 2012. We have passed ISO9001:2008accreditations. We win the trust from every customer on the principle of “the best quality and the shortest delivery time”. We all staff adhering to the principle of “ Honesty, diligence, sharing and innovation”. Take EFD15D type bobbin as an example:
(1) PIN NO. : 5:5P
(2) PIN PITCH: 2.54
(3) ROW PITCH: 14.8/21.35
(4) PIN DIAMETER: 0.4*0.7
The following is a data table about all the specifications of EFD type bobbin provided by our factory.
2. Development Trend of Electronic Transformer Market
At present, China's electronic transformer market is basically in a stable state. As the electronic transformer is a labor-intensive product, China's labor costs are relatively low, the industry has not been greatly impacted, and the export side has been further increased.
Opportunities and challenges:
·The electronic transformer market is basically in a stable state.
·The development trend of electronic transformer technology is miniaturization of products
·China's electronic transformer production accounts for more than 20% of the global total output.
·Private enterprises have accounted for about 50% of the electronic transformer industry.
·Last year, China's export of electronic transformers approached 1.2 billion yuan, an increase of 2.66% over the same period last year.
In order to meet the needs of market economy and supporting systems, the operation mechanism of electronic transformer industry has changed greatly in recent years. According to the statistics of trade associations, private enterprises have accounted for about 50% of the electronic transformer industry. At present, China's electronic transformer market is basically in a stable state. As the electronic transformer is a labor-intensive product, China's labor costs are relatively low, the industry has not been greatly impacted, and the export side has been further increased. Last year, China's export of electronic transformers approached 1.2 billion yuan, an increase of 2.66% over the same period last year. At present, the electronic transformer products in China are still the traditional products produced in the past decades. They still use silicon steel sheet, ferrite, enameled wire, transformer equations, transformer efficiency, transformer electronics, plastic bobbin as the main raw materials and components. In order to support new electronic products, R-type iron core technology has been introduced in recent years, R-type transformer has been developed, and the quality level of electronic transformer has been further improved.
Electronic transformer is one of the parts with large volume and heavy weight in electronic products. In order to meet the demand of miniaturization development of electronic products, the market will certainly promote the development of electronic transformer products in the direction of light weight. More importantly, with the change of the performance of the whole machine, it will drive electronic transformer products to high frequency, low loss, surface mounting and new materials, new structure of new transformer development direction.
China's electronic transformer production accounts for more than 20% of the global total output, and China has become the main supply base in the international market. With the increasingly fierce competition in the international market, in order to reduce costs, transformer energon, transformer emblem, transformer equivalent circuit, transformer production will be further promoted to form scale benefits to adapt to the more intense market competition.
3. What Is The Difference between High Frequency Transformer and Inductance?
High-frequency transformer and inductance have the same point: high-frequency transformer and inductance are wrapped with enameled wire, with iron core or magnetic core inside. High-frequency transformer and inductance are different: transformer is mainly used for voltage conversion, which is based on the law of electromagnetic induction.
Inductor coils are generally used in electronic circuits, according to Lenz's law. The former usually has two or three windings, including primary winding and secondary winding. For boost transformer, the primary winding turns are few, the secondary winding turns are many and the line diameter is fine. On the contrary, step-down transformer has many primary windings and small secondary windings, which are widely used as power supply in various electrical appliances.
Transformer is a device to change AC voltage, current and impedance. When AC current is applied to primary coil, AC flux is generated in iron core (or magnetic core) to induce voltage (or current) in secondary coil. The transformer consists of iron core (or magnetic core) and coil. The coil has two or more windings. The winding connected with the power supply is called primary coil, and the other windings are called secondary coil.
Inductor coil is a device which works on the principle of electromagnetic induction. When a current flows through a conductor, it will generate a certain electromagnetic field around the conductor, and the conductor of the electromagnetic field itself will induce the conductor within the scope of the electromagnetic field.
4. What Is The Cause of Transformer Bobbin Failure?
1). Analysis of the causes of transformer bobbin failure
Based on the analysis of the previous casing faults, the following main reasons are concluded:
After the dirty surface of the casing absorbs moisture, the insulation resistance decreases, and the consequence is that flash-over easily occurs, resulting in tripping. At the same time, flash-over can also damage the surface of casing. When dirt absorbs water, the conductivity increases, which not only causes surface flash-over, but also may cause insulating bushing to heat up and cause ceramic damage or even breakdown due to the increase of leakage current. Due to the failure of casing gasket seal, the top seal of oil-paper capacitive casing is not good, which may lead to the breakdown of insulation caused by water intake, and the leakage of oil caused by poor bottom seal, resulting in the decline of oil surface. There are two main reasons for casing seal failure: one is insufficient tightening force due to insufficient experience of maintenance personnel; the other is insufficient quality of rubber pad due to over-cycle operation.
Others, such as grounding small bushing failure, which causes suspension potential and partial discharge at the end screen of the bushing; the structure of the bushing itself is unreasonable, and there are defects. For example, some transformer bushings in transformer bobbin are welded by tin welding, 220 KV A-phase bushings are aluminium tubes, conductor heads are copper and rain caps are aluminium. This copper-aluminium connection increases the contact resistance, transformer earth wars, e transformer winding, e transformers 5, sinters the rain cap and conductor heads, and burns the lead and conductor heads.
In addition, the casing oil standard pipe is dirty and the oil level can not be seen clearly, resulting in oil deficit after annual pre-test sampling. For example, in casing overhaul, the vacuum is not exhausted thoroughly, which makes the residual air between the screens. Under the action of high electric field after operation, partial discharge occurs, and even leads to the breakdown of insulation layer, resulting in accidents. Moreover, the structure of casing head is not reasonable. For example, the contact between the lead head and the rain cap is not close; the rain cap and the wiring nose are not close; the wiring nose and the wiring plate are not in good contact, resulting in increased contact resistance and hot sintering of the wiring joint.
2). In different environments, the use of transformer skeleton is different, such as:
·In the electronic amplifier circuit, impedance matching and transformer bobbin connection can change the impedance in order to achieve the transfer energy consumption between two lines of amplifier.
·In AC regulator, the output voltage can be adjusted by changing the number of coils in real time.
·In order to reduce the loss of long-distance input lines, the output power from power plants should be boosted to tens of thousands of volts (e.g. 11KV), and then lowered to the destination (e.g. 220V).
·Sometimes, different voltages are needed in an environment, and transformers can be made into multi-windings or intermediate taps. It generates a variety of voltages.
·When welding, the current required between the electrode and the weldment is very large (tens to hundreds of amperes), while the voltage is very small (several volts). Welding machine is a transformer, which turns high voltage (such as 220V) into low voltage. Without changing the power, a large current is generated at the output end.
5. Circuit Principle of Switching Power Transformer
Switch is the most common and indispensable component in our daily life, and the switched power transformer is widely used in the circuit system. We all know that the switched power transformer is mainly composed of switched power supply and transformer, e transformers 4, ebay transformers, transformer e i core dimensions, but few people know what its circuit principle is. Today we are one of them. Let us see the circuit principle of the switching power transformer.
1. Load sharing is a key technology, which reduces the unbalanced output of parallel modules and makes the system have redundant fault-tolerant capability, which is easy to constitute a large capacity.
2. Power factor calibration technology can restrain harmonic current of power grid side, reduce reactive power, improve power factor, and reduce noise and pollution caused by high-order harmonics of power supply, so as to achieve the purpose of energy saving.
3. It depends on whether it adopts frequency conversion control or constant frequency control. Constant frequency control (also known as phase shift control) method is better than variable frequency control method. Full-bridge converter with phase-shift control combines the advantages of constant frequency control technology and soft-switching technology, realizes constant frequency control in a wide range, realizes step-less regulation of output voltage or current in a wide range, and realizes zero-voltage switching commutation in the instantaneous commutation of power devices.
4. It depends on whether it adopts hard-switching technology or soft-switching technology. Various loss-free buffer circuits consisting of LC passive components and fast recovery diodes have changed the switching transition process of the switch, making the switching voltage and current change slowly rather than gradually (i.e. hard switching), thus significantly reducing the switching loss of power devices and improving the switching of the system. Frequency reduces the volume and weight of transformer, reduces the output ripple of the system, overcomes the sensitivity of the converter circuit to parasitic dispersion parameters, reduces the switching noise of the system, widens the frequency band of the system, and improves the dynamic and static performance of the system.