News-Changzhou Shengdan Co., Ltd.

Changzhou Shengdan Electrical Equipment Co., Ltd.

News

Location: Home

2020

Do you know the working mode and characteristics of switching power supply manufacturers?

2020

Switching power supply manufacturers teach you how to deal with the filtering?

After Xiaobian's research, it is found that a small number of components will fail in the switching regulator power supply. The general fault is the switching transistor itself. Because the short circuit of the transistor fails, the fuse will burn when a lot of current flows through the transformer. Transistor failure is actually caused by bad capacitors. Therefore, capacitors are specially designed to solve the strict filtering in switching power supply manufacturers. Many switching power supply manufacturers will still use low ESR capacitors as the first installation of machinery and equipment, because it will also be much more expensive than traditional capacitors. Can be used as a replacement part, which can improve the life of the power supply. If you use a power supply, you can replace a lot of output filter capacitors with low ESR capacitors without looking good. Many tests are performed with power outages. Test a pair of switching transistors from a switching power supply manufacturer. This method is only used on heat pipe radiators and is used to assist in their cooling. Test according to the ohmmeter or meter set to the diode test category according to the application. Check for a short circuit between the emitter and collector of each transistor. In exchange, many transistors were found to be unqualified. While some staff claim that even if just one of them is not good you should change them, I don't think that's the case. By the way, this transistor seems to be testing for a short circuit between the base and the emitter all the time during the "in-circuit" test. When the switching transistor of the switching power supply manufacturer fails, there is a short-circuit failure between the emitter and the collector. If in doubt, pull the transistor out of the power circuit for testing. If the transistor shorts out, the fuse will blow. Please additionally test the high voltage diode. Although high voltage diodes can be stand-alone diodes, they are generally part of a bridge rectifier.

2020

The switching power supply manufacturer tells you how the ripple is generated?

If you don't know, you can just follow the editor to understand how the ripple of the switching power supply manufacturer is generated. In fact, it is to reduce the output ripple to an acceptable level. If there is more than this, then reduce the ripple, but we need to know the type and cause of the ripple of the switching power supply manufacturer. With the switching of the SWITCH, the current in the inductor L actually floats up and down the effective value of the output current. Therefore, a ripple of the same frequency will also appear at the output end. Generally speaking, this is the ripple. It is related to the volume and ESR of the output capacitor. The frequency of this ripple is the same as that of the switching power supply manufacturer. Another is that the bipolar rotator or MOSFET is generally used, but no matter what it is, there will be a rise time and a fall time when it is turned on and off. In the power supply circuit, there will be a frequency of the same rise and fall time as before, or the noise of an odd number of optical lenses is usually tens of MHz. The same diode D has a reverse recovery moment, and its equivalent circuit is the series connection of electronic components and inductors, which will cause resonance, and the resulting noise frequency is also several tens of MHz. These two types of noise are often referred to as high frequency noise, and the magnitude is generally much larger than the ripple. If it is an AC/DC converter, in addition to the above two kinds of ripple noise, there is also AC noise. The frequency is the frequency of the manufacturer of the AC switching power supply, which is around 50 to 60 Hz. There is also this common mode noise, which is caused by the equivalent capacitor caused by the application of the chassis as a heat pipe radiator in the power electronic devices of many switching power supply manufacturers.

2020

Power transformer manufacturers describe the working principle

Its output and input use a special transformer with the same set of coils, and the step-up and step-down are also realized by using different taps. The tap voltage of the part with less coils that can be shared will decrease, and the part with more coils than the shared coil will be used. That is, the tap voltage will increase. In fact, this principle is the same as that of ordinary power transformer manufacturers. This is only that its original coil is the secondary coil. Usually, the primary coil on the left passes through electromagnetic induction, so that the secondary coil on the right generates voltage, and the autocoupling will also have an impact. of. Autocoupling is a power transformer manufacturer with only one winding. When used as a step-down, a part of the turns can be extracted from the winding as a secondary winding. If used as a boost, the applied voltage can be applied to some turns of the winding. Generally, the part that belongs to the primary and secondary is called the common winding, and the rest of the auto-coupling is also called the series winding. Compared with the common auto-coupling of the same capacity, it is not only small in size, but also very efficient. High. This capacity is also relatively large, and the voltage will be very high, so the advantages are more prominent. With the continuous development of the power system, the improvement of the voltage level and the increase of the transmission capacity, the autocoupling has been widely used because of its large capacity, low loss and low cost. From this, we can see the principle of power transformer manufacturers. This cannot have separate primary winding and secondary winding, and only one coil can achieve the purpose of voltage conversion. When the primary winding is connected to the AC power supply, the voltage of each turn of the primary winding will decrease, and the voltage will be evenly distributed in the primary winding. The voltage of the secondary winding is also equal to the voltage of each turn of the primary winding multiplied by the number of turns of three or four. Hope you can learn more about it too.

2020

What factors need to be considered when choosing a good switching power supply manufacturer?

In fact, to put it plainly, it is the same as buying things by yourself. They are all factors that need to be considered comprehensively. Some of them also need to shop around, so that you can choose the right product with high cost performance. So what factors need to be considered when choosing a good switching power supply manufacturer? Follow along with me to find out! 1. Have a suitable input voltage range. Switching power supply manufacturers use AC input as an example. Common input voltage specifications are 110V and 220V, so there are several specifications for these two types of AC conversion and universal input voltage. Also select the input voltage specification according to the region of use. 2. Appropriate output power. The power transformer of the switching power supply manufacturer consumes part of the power when it is working, and at the same time releases it in the form of heat. The editor reminds everyone that in order to increase the use time of switching power supply manufacturers, it is recommended to use models with a power rating of 30%. 3. Consider the characteristics of the load. In order to improve the reliability of the system, it is recommended that the transformer of the switching power supply manufacturer is better at 50% to 80% load. 4. If the load is a motor, a light bulb or a capacitive load, the current is very large at the moment of startup, and a suitable power supply should be used to prevent the load. If the load is a motor, take into account the voltage reverse wind when shutting down. 5. In addition, everyone should also consider the working environment, whether there is any additional auxiliary cooling equipment, and the power supply needs to reduce the rated output under high ambient temperature. 6. Try to use the standard switching power supply manufacturer produced by the manufacturer. Of course, this also includes the standard specification and output voltage. In that way, the delivery time is faster; on the contrary, the unique specifications and output voltage will increase the delivery time and increase the cost.

2020

Do you know how to solve the internal and external interference problems of switching power supply manufacturers?

Usually, it is divided into two categories, namely, the interference formed by the internal components of the switching power supply manufacturer. There is also the interference caused by the switching power supply manufacturers affected by external factors. Both of these involve human and natural factors. First, the internal interference of switching power supply manufacturers Switching power supply manufacturers say that the key to EMI is the high-order harmonic current interference caused by the basic ballast and the peak voltage interference caused by the output power conversion circuit. 1. There is a distributed capacitance between the switch tube and the heat pipe radiator and the leads inside the chassis and power supply. When the switch tube passes through a large pulse current, the waveform has many high-frequency components. At the same time, the main parameters of the components used in power-off applications, such as the storage time of the switching power tube, the large current of the output stage, and the reverse recovery time of the switching rectifier diode, will cause the control loop to be short-circuited instantaneously, resulting in a large short-circuit current. , The load of the switch tube is a high-frequency transformer or an inductor of energy storage technology. At the moment when the switch tube is turned on, a large inrush current occurs at the primary stage of the transformer, resulting in peak noise. 2. The transformer in the high-frequency transformer switching power supply is used as protection and transformer, but due to leakage inductance, it will cause electromagnetic induction noise. At the same time, in the case of high frequency, the distributed capacitance between the layers of the transformer will transmit the high-order harmonic noise on the multiple side to the secondary, and the distributed capacitance of the transformer to the chassis forms another high-frequency loop, which makes the transformer form another high-frequency loop. Magnetic fields caused by the surrounding are more likely to couple to other leads to form noise. Second, the external interference of switching power supply manufacturers The external interference of switching power supply manufacturers can exist in common mode or differential mode. The type of disturbance can vary from short-duration spike disturbances to complete power outages. At least voltage transitions, frequency transitions, waveform dropouts, constant noise or low frequency oscillations are included. The key that can be transmitted according to the power supply and cause the destruction of the equipment or affect its work is the rapid electrical transient monopulse and surge shock wave, and the interference such as electrostatic discharge, if the power supply equipment itself does not cause problems such as vibration stoppage and output voltage drop, it will be It is not easy to cause the impact on the power-consuming equipment caused by the power supply.

< 1 2 3 4 5 6 >

www.300.cn Changzhou SEO Add:No. 4, Yinhua Road, Zhonglou District, Changzhou E-mail: zxd@linke.cn Tel:+86-519-83881855 83883887

Business license