1. Do You Know Something About RM Type Bobbin?? ? ? RM type bobbin is generally used to make inductors and transformers with EMI requirements., which is used together with RM type magnetic core. EMI stands for Electric Magnetic Interference. Power supply is an important source of EMI. EMI circuit in the power supply circuit is used to filter out all kinds of interference signals from the power grid to prevent high frequency interference from the power switch circuit, or to cause interference to the equipment and application environment. Generally , RM bobbin is vertical bobbin that can be used to make multiplex output transformer. The inductor transformer with strong anti-interference ability and good shielding effect can be designed. However, due to the influence of product structure, the heat dissipation performance is poor. It is used for the production of main power transformer, auxiliary power transformer, drive transformer. The bobbin is mainly applied in carrier communication, network, digital television, precise electronic equipment and other fields. Under a series of national policies, the market of relevant industry is pulled energetically, the transformer equipment market will usher a new spring in two years. TAKE RM6 TYPE BOBBIN AS AN EXAMPLE:
1. Do You Know Something About RM Type Bobbin?
RM type bobbin is generally used to make inductors and transformers with EMI requirements., which is used together with RM type magnetic core. EMI stands for Electric Magnetic Interference. Power supply is an important source of EMI. EMI circuit in the power supply circuit is used to filter out all kinds of interference signals from the power grid to prevent high frequency interference from the power switch circuit, or to cause interference to the equipment and application environment. Generally , RM bobbin is vertical bobbin that can be used to make multiplex output transformer. The inductor transformer with strong anti-interference ability and good shielding effect can be designed. However, due to the influence of product structure, the heat dissipation performance is poor. It is used for the production of main power transformer, auxiliary power transformer, drive transformer. The bobbin is mainly applied in carrier communication, network, digital television, precise electronic equipment and other fields. Under a series of national policies, the market of relevant industry is pulled energetically, the transformer equipment market will usher a new spring in two years.
TAKE RM6 TYPE BOBBIN AS AN EXAMPLE:
(1) PIN NO. : 4:4P
(2) PIN PITCH: 3.65
(3) ROW PITCH: 11.0/14.5/18.0
(4) PIN DIAMETER: φ0.5
THE FOLLOWING IS A DATA TABLE ABOUT ALL THE SPECIFICATIONS OF RM BOBBIN, WHICH PROVIDED BY OUR FACTORY.
2. R-type transformer is the latest type of transformer
R-type transformer is the latest transformer product in the world. R-type transformer breaks the traditional C-type, E-type and ring-type transformer with square core section. It adopts a continuous winding of a high-quality silicon steel strip from narrow to wide and from wide to narrow and uniform transition. The core is non-cutting and the cross section is approximately circular. Compared with the traditional C-type and E-type transformers, inductor lite, inductor led circuit, l inductor symbol, l inductor calculator, it has the remarkable characteristics of small magnetic flux leakage, low temperature rise, small size, light weight and no noise. It can be widely used in audio and television broadcasting equipment, medical instruments, instruments, satellite receivers, photocopiers, computers, electronic balances and various electronic instruments and equipment.
The core of R-type transformer has no magnetic gap and the winding is balanced, so the magnetic leakage is small. No anti-leakage measures need to be designed. Noise-free heat generation is small, because R-type transformer is winded with non-cutting iron core and made of orientated high-grade silicon steel sheet produced by Nippon Iron Corporation of Japan. It has uniform circular cross-section and continuous winding. Resistance loss and heat generation are very low, and without cutting, magnetostrictive stress can be easily absorbed, thus ensuring. The application is noise-free.
The small excitation current design is reasonable, so it has the characteristics of low iron loss, less heat generation, low excitation current and energy saving. Because of its unique design, the primary and secondary skeletons are separated and the insulation performance is excellent. The separated skeletons made of flame retardant materials can meet the standards of any country.
3. Technical Status of Small and Medium Power Inverter for Photovoltaic System
Inverter power supply can be divided into power frequency conversion and high frequency conversion. Power frequency conversion is to use discrete devices or integrated blocks to generate 50Hz square wave signal, then use the signal to drive the power switch, and use power frequency boost transformer to generate 220V AC. This kind of power supply has simple structure and reliable operation, but it is not suitable for inductive loads, such as refrigerators, inductor l formula, an inductor (l=400mh), an inductor l of reactance xl is connected, fans, pumps, fluorescent lamps and so on, because of the defects of the circuit structure itself. In addition, this kind of inverter power supply is bulky, bulky and expensive because of its power frequency transformer. At present, it is mainly used in large-scale solar photovoltaic power plants.
In the early 1970s, the application of 20 kHz PWM switching power supply caused the so-called "technological revolution of 20 kHz power supply" in the world. This idea was used in the inverting power supply system at that time, but because of the expensive power devices and high loss, the research of high frequency and high efficiency inverting power supply has been at a standstill. After the 1980s, with the maturity of power MOSFET technology and the improvement of magnetic material quality, high-frequency conversion inverters came to market.
High-frequency converter is a high-frequency DC/DC converter, which first converts low-voltage DC into high-frequency low-voltage AC, and then rectifies it into high-voltage DC after boosting the pulse transformer. Because PWM technology is used in DC/DC conversion, a stable DC voltage can be obtained here, which can directly drive AC energy-saving lamp, incandescent lamp, color TV and other loads. If the HVDC is converted into sinusoidal or sinusoidal converter, 220V, 50Hz sinusoidal or 220V, 50Hz sinusoidal alternating current can be obtained. This kind of inverter is small in size and light in weight because of its high frequency conversion (now mostly 20 kHz to 200 kHz). Because of the adoption of secondary width regulation and secondary voltage stabilization technology, the output voltage is very stable, the load capacity is strong, and the performance-price ratio is high. It is the preferred product in the renewable energy power generation system at present. In developed countries, small and medium-sized AC photovoltaic systems are widely used, but in China, due to technical reasons and market chaos, some inverters manufacturers have been promoting power frequency conversion inverters, some of which even use low silicon steel sheets in order to reduce costs. Such inverters flooded the market, making AC light. The higher comprehensive cost of the voltage system will hinder the promotion of the AC photovoltaic system, which is very harmful to the development of the industry.
4. Differential Mode Noise and the Working Principle of Differential Mode Filter Inductor
The square wave harmonics and spike disturbances caused by digital circuits, switching power supply, power electronic switches and motor loads are usually differential mode noise disturbances to power network. The suppression method of differential mode interference is usually a low pass filter composed of differential mode filter inductor and differential mode capacitor.
The working principle of differential mode filter inductor is that the core is unsaturated when the filter inductor coil flows through the low-frequency peak current or DC current of the power line, while maintaining enough incremental permeability and inductance to ensure the resistance and blocking effect to high-frequency interference noise.
5. Requirements of Differential Mode Inductors for Soft Magnetic Materials
The basic requirement for the core of differential mode inductor is to have as high inductance as possible in the required interference frequency band and under the condition of unsaturated rated current. Therefore, the core material should have the following characteristics:
(1) Constant permeability: unsaturated at rated low-frequency peak bias (or DC) ampere turns, with high linear incremental permeability and inductance, i.e. good AC-DC superposition characteristics.
(2) High saturation magnetic inductance Bs.
(3) Good frequency characteristics.
(4) Good temperature stability. The core materials of common soft magnetic materials for differential mode inductors can be divided into two categories (arranged in the order of excellent to poor high frequency characteristics). (1) The core materials with air gap: ferrite, amorphous alloy (FG type), permalloy (thin) and thin silicon steel. (2) Core materials without air gap: iron-nickel-molybdenum powder core (MPP), constant magnetic conductivity amorphous alloy (FJ, HD), an inductor (l=0.03h) and a resistor, inductor magnetic field, inductor meaning, iron-silicon-aluminium powder core (SENDUST), high magnetic flux powder core (HF), iron powder core and Permo constant magnetic conductivity alloy (1J-h type ), etc.
6. Circuit Design of EMI Filter for Switching Power Supply
When the harmonic level of switching power supply is displayed on the power line in the low frequency band (frequency range 0.15-30MHz), it is called conductive interference. It is relatively easy to suppress the conducted interference, so long as the appropriate EMI filter is used, the EMI signal level on the power line can be suppressed within the limits prescribed by the relevant standards. In order to make EMI filter have the best attenuation performance for EM signal, the impedance of the filter should be mismatched with the impedance of the power supply. The more mismatched, the more ideal the attenuation is, the better the insertion loss characteristic is obtained. That is to say, if the internal resistance of the noise source is low, the input impedance of the EM filter connected with it should be high (e.g. the series inductance with large inductance); if the internal resistance of the noise source is high, the input impedance of the EMI filter should be low (e.g. the parallel capacitance with large capacity). This principle must also be followed in designing EMI filters for suppressing switching power supply.
Conducted interference of almost all devices includes common mode noise and differential mode noise, and switching power supply is no exception. Common mode 1000 disturbance is caused by the potential difference between the current-carrying conductor and the earth. Its characteristic is that the noise voltage on the two lines is the same potential and the same direction, while the differential mode disturbance is caused by the potential difference between the current-carrying conductor, inductor model, inductor measurement, inductor markings, and its characteristic is that the noise voltage on the two lines is the same potential and reverse. Usually, the two components of the interference voltage on the line exist at the same time. Because of the unbalance of line impedance, the two components will change with each other in transmission, and the situation is very complicated. Typical EMI filters include common-mode noise and differential-mode noise suppression circuits.