Switching power supply is a voltage conversion circuit, the main job is to step-up and step-down, widely used in modern electronic products. Because the switching transistor always work in the "open" and "off" state, so called switching power supply. Switching power supply is essentially an oscillating circuit. This method of converting power is not only used in power circuits, but also widely used in other circuit applications, such as backlight circuits of liquid crystal displays and fluorescent lamps. Compared with the transformer, the switching power supply has the advantages of high efficiency, good stability, small volume, etc. The disadvantage is that the power is relatively small, and the circuit generates high frequency interference. The transformer feedback oscillation circuit can generate a regular pulse current or voltage The circuit is called the oscillator circuit, the transformer feedback oscillation circuit is able to meet this condition of the circuit

TV switching power supply circuit, there are many chassis charged, so maintenance must take safe overhaul measures, otherwise it will cause the human body electric shock. 1. The use of isolation transformers in power grid and TV power input end, plus a 1: 1 isolation transformer, so that the TV chassis ground with the power line can not be directly connected. Access to the isolation transformer, the power must be greater than the power of the TV, about 100W p Insulation between the workbench and the ground Pad a thick rubber floor or plastic plate between the workbench and the ground to isolate the human body from the earth and prevent electric shock.   3. Disconnecting the ground wire of the measuring instrument When using the measuring instrument for overhauling the TV, if there is no isolation transformer, in order to prevent the live wire of the power grid from short-circuiting through the shell of the TV set and the shell of the measuring instrument, The ground in the head is disconnected, making its case no longer grounded.

The efficient use of magnetic components is crucial to the development of switching power supplies. The use of magnetic amplifiers as high-reliability control components has become a staple technology, with diamond-core amorphous cores playing a leading role. However, when the switching frequency is as high as MHz, an amorphous magnetic core with a film thickness of several microns is needed. At present, further research is needed in this respect. In addition, the use of amorphous magnetic cores (the same principle as magnetic amplifiers) in magnetic buffers has become an essential technique for powering high frequencies. At the same time, as a main transformer core, we can not ignore the high-frequency ferrite and super-cooling core crystal research and development work. It seems that the application of resonant switch resonant inductor and the development of high-frequency magnetic materials relatively slow some hope of new breakthroughs in this area. Including the main transformer, in general, the loss generated by the magnetic element is proportional to the frequency of the power of 1-2, and not as easily dissipated through the heat sink outward as in the semiconductor device, therefore, The fever is also an important issue.

Terminal power supply is designed for user-friendly installation, can be installed directly, without printed circuit board. All using terminal outlet way. This product has a variety of series to meet the needs of different users, select the terminal power supply not only can reduce the power system design on the many troubles, but also reduce design costs and effective use of space savings.

Regulated power supply performance indicators are divided into two kinds, one is the characteristic index, the other is the quality index.

Monolithic switching power supply chip integration is high, it will PWM control system, all the features integrated in the chip. The external circuit is simple and can be configured as a universal switching power supply or power supply module by adapting the AC-to-85-265V, 47-440H: AC input rectifier filter. It is competitive in price with a linear regulated power supply of equal power, with significantly improved power supply efficiency, significantly reduced size and weight. The current production of the monolithic switching power supply are TOPSwitch, TOPSwitch a HTinySwitch, TNY256, MC33370, TOPSwitch a FX six series. In addition, L4960 series, L4970 / L4970A series monolithic switching regulator, a total of eight series, more than 80 kinds of models. Among them, TOPSwitch, TOPSwitch-II, TinySwitch, TNY256 and a TOPSwitch a FX series, are the United States PI company's products; MC33370 series} IJ is a Motorola (Motorola) products; L4960, L4970 / L4970A series for a law Semiconductor Co., Ltd. SGS-Thomson) products. According to the number of leads, monolithic switching power supply can be divided into three ends, four ends, five ends, a total of four kinds.