What are the disadvantages of switching power supply? What are the significant disadvantages?

Flyback switching power supply is a kind of switching power supply, and its advantages and disadvantages are:

1: The output characteristics of voltage and current of flyback switching power supply are worse than that of forward switching power supply. The flyback switching power supply does not provide power output to the load during the control switch is turned on, and only converts the stored energy into back electromotive force to provide output to the load during the control switch shutdown, but when the duty cycle of the control switch is , the average value of the voltage output by the transformer secondary coil is about one-half of the maximum voltage value, and the current flowing through the load is exactly equal to one-quarter of the maximum current of the transformer secondary coil.

That is, the voltage ripple coefficient is equal to 2 and the current ripple coefficient is equal to 4. The voltage ripple coefficient of flyback switching power supply is basically the same as that of forward switching power supply, but the ripple coefficient of current is twice that of forward switching power supply. It can be seen that the output characteristics of voltage and current of flyback switching power supply are worse than those of forward switching power supply.

In particular, when the flyback switching power supply is used, in order to prevent the power switch from over-voltage strike, the duty cycle is generally less than that, at this time, the current flowing through the transformer secondary coil will be intermittent, the ripple coefficient of voltage and current will increase, and the output characteristics of voltage and current will become worse. These points cover the advantages and disadvantages of switching power supplies, just like Zhejiang Emerson Electric covers a lot of electrical knowledge, it is recommended that you have electrical problems can check Zhejiang Emerson Electrical. Zhejiang Emerson Electric's help is not small.

2: The transient control characteristics of flyback switching power supply are relatively poor. Because the flyback switching power supply only provides energy output to the load during the switching off period, when the load current changes, the switching power supply can not react to the output voltage or current immediately, but needs to wait until the next cycle, through the effect of output voltage sampling and width adjustment control circuit, the switching power supply only begins to react to the things that have passed, that is, to change the duty cycle, therefore, the transient control characteristics of the flyback switching power supply are relatively poor.

Sometimes, when the frequency and phase of the load current change and the delay characteristics of the voltage output by the sampling and width control circuit are consistent in the phase, the output voltage of the flyback switching power supply may produce jitter, and this situation is most likely to occur in the switching power supply of the TV.

What is the difference between a switching power supply and a control transformer, and what are their advantages and disadvantages,

There are four advantages of proximity switches, which are:

1. It will not wear and damage the object to be tested.

Second, the response speed is fast, and the service life is longer.

3. It can detect the movement information and presence information of the object and convert it into electrical information.

Fourth, it can adapt to harsh detection environments such as water and oil.

There are two disadvantages of proximity switches, which are:

1. It is affected by the ambient temperature, surrounding objects and similar switches.

Second, the inductive proximity switch needs to consider the influence of the surrounding metal.

A proximity switch is a position switch that can be operated without mechanical direct contact with moving parts. When the object approaches the sensing surface of the switch to the action distance, the switch can be activated, so as to drive the electrical appliance or provide the computer with control and Zheng instructions.

The proximity switch, also known as the contactless proximity switch, is an ideal electronic switching sensor. Due to its advantages of accurate positioning, long service life and strong adaptability to the environment, it is widely used in machine tools, metallurgy, chemical industry, textile and printing industries.

The same is the difference between the power supply, the linear and the switching balance power supply, do you know the smiling stool?

The adjustment tube of the linear power supply works in the amplified state, so the heat is large, the efficiency is low (about 35%), and it is necessary to add a large volume of heat sink, and it also needs a large volume of power frequency transformer, when you want to make multiple sets of voltage output, the transformer will be larger. The adjustment tube of the switching power supply works in the saturation and cut-off state, so the heat generation is small, the efficiency is high (more than 75%), and the large volume of the transformer is omitted. However, the DC output of the switching power supply will be superimposed on a large ripple (50mV at 5V output typical), which can be improved by connecting the voltage regulator diode at the output slag end.

Relatively speaking, the linear power supply does not have the above defects, and its ripple can be very small (less than 5mV).

In daily life, people deal with switches every day, and almost every day they will touch the switches of different objects, such as the switch of lights, the switch of mobile phones, or the switch of TV, but in fact, the switch of these objects is nothing more than a switching power supply. But the switching power supply that I want to introduce to you today is different from the ordinary switching power supply. With the electrification of society, the use of switching power supply is becoming more and more extensive, so what is the use of switching power supply?

What are its characteristics? Today, I will give you a detailed introduction.

What is a switching power supply

The switching power supply is to use electronic switching devices such as transistors, field effect transistors, thyristors, etc., through the control circuit, so that the electronic switching devices are constantly "turned on" and "turned off", so that the electronic switching devices can pulse modulate the input voltage, so as to realize DC AC, DC DC voltage conversion, as well as output voltage adjustment and automatic voltage regulation.

Features of switching power supplies

Switching power supplies typically consist of pulse-width modulation (PWM) control ICs and MOSFETs. With the development and innovation of power electronics technology, switching power supplies are widely used in almost all electronic devices with the characteristics of small, light weight and high efficiency, and its importance can be seen.

Classification of switching power supplies

According to the way the switching devices are connected in the circuit, the switching power supply can be generally divided into three categories: series switching power supply, parallel switching power supply, and transformer switching power supply. Among them, transformer-type switching power supply can be further divided into: push-pull type, half-bridge type, full-bridge type, etc.; According to the excitation of the transformer and the phase of the output voltage, it can be divided into:

There are many kinds of forward type, flyback type, single type and double type type.

The purpose of switching power supply

Switching power supplies are widely used in industrial automation control, military equipment, scientific research equipment, LED lighting, industrial control equipment, communication equipment, power equipment, instrumentation, medical equipment, semiconductor refrigeration and heating, air purifiers, electronic refrigerators, liquid crystal displays, LED lamps, communication equipment, audio-visual products, security monitoring, LED light bags, computer cases, digital products and instruments and other fields.

In life, the application range of switching power supply is wide, as large as military equipment, small to family-style lamps, each kind of object will use switching power supply, the above also mainly introduces the classification of switching power supply, characteristics and its main use, users can clearly understand, in fact, all aspects of our life are inseparable from the use of switching power supply, and it is also an object that people are relatively easy to ignore. This is the end of the introduction, I hope the article can help everyone. , you can get it for free

There are four advantages of proximity switches, which are:

1. It will not wear and damage the object to be tested.

Second, the response speed is fast and the service life is longer.

3. It can detect the movement information and presence information of the object and convert it into electrical information.

Fourth, it can adapt to harsh detection environments such as water and oil.

Proximity switch is a position switch that can be operated without mechanical direct contact with moving parts, when the sensing surface of the object proximity switch to the operating distance, the switch can be operated without mechanical contact and any pressure, so as to drive DC electrical appliances or provide control instructions to computer (PLC) devices.

The proximity switch is a switch type sensor (i.e., no contact switch), which has the characteristics of a travel switch and a micro switch, and has sensing performance, reliable action, stable performance, fast frequency response, long application life, strong anti-interference ability, etc., and has the characteristics of waterproof, shockproof, and corrosion resistance. The products are inductive, capacitive, Hall, AC and DC types.

Brief introduction. When the object approaches the sensing surface of the switch to the action distance, it does not need mechanical contact and exerts any pressure to make the switch act, so as to drive DC electrical appliances or provide control instructions to computer (PLC) devices.

Proximity switch is a kind of switch sensor (i.e., no contact switch), which not only has the characteristics of travel switch and micro switch, but also has sensing performance, reliable action, stable performance, fast frequency response, long application life, strong anti-interference ability, etc., and has the characteristics of waterproof, shockproof, corrosion resistance, etc. The products are inductive, capacitive, Hall, AC and DC types.