What is the difference between switching power supply and transformer?
Writer： Hengfeng you electric Time：2023-03-27 views：times
Abstract: What is the difference between switching power supply and transformer? The switching power supply has the protection functions of overcurrent, overheating, short circuit, etc. The voltage input range is wide, the insulation voltage between input and output is high, and the insulation voltage between insulated input and output is high. Transformer is a device that uses electromagnetic induction principle to transform voltage, current and impedance. The main application of transformer is alternating circuit.
Differences between switching power supply and transformer:
Switching power supply is a power supply that uses modern power electronics technology to control the time ratio of switching transistors on and off and maintain a stable output voltage. Switching power supply is divided into AC/DC and DC/DC; According to whether there is electrical isolation between input and output, it can be divided into two categories. One is called isolated DC/DC converter; Another type of converter is called a non isolated DC/DC converter. The switching power supply has the protection functions of overcurrent, overheating, short circuit, etc. The voltage input range is wide, the insulation voltage between input and output is high, and the insulation voltage between insulated input and output is high.
Transformer is a device that uses electromagnetic induction principle to transform voltage, current and impedance. The main application of transformer is alternating circuit.
What is switching power supply
Switching power supply is a power supply that uses modern power electronics technology to control the time ratio of switch on and switch off, and maintain a stable output voltage. Switching power supply is usually composed of pulse width modulation (PWM) control IC and MOSFET.
Advantages and disadvantages of switching power supply
advantage:
1. High efficiency and small size. Because the voltage control of switching power supply is realized by adjusting the conduction time or frequency of power semiconductor devices in the saturation area, there is no iron loss and copper loss, and the loss of components can be ignored, which is higher than the efficiency of transformer; Because there are only parts and circuit boards, it is small in size and light in weight.
2. The voltage input range is wide, generally reaching 160V-270.
Disadvantages:
1. The switching power supply looks small, its power is related to the iron core transformer and the control mode, its electromagnetic interference is large, and its ripple coefficient is large. Especially in the field of audio and video, it is very sensitive to electromagnetic interference, and the voice color in audio may be impure, with silky sound; In the video, there are small ripples in the image, which may not be thin enough.
2. Complex design and inconvenient maintenance. The more complex the equipment, the higher the possibility of problems. In addition, if there is a problem with the switching power supply, it generally requires professional personnel to repair it. If you entrust someone else to repair it, the cost is too high, so you'd better throw it away.
3. Small size is the advantage of switching power supply, and poor design is its disadvantage. In order to pursue smaller things, if large parts are stuffed into small enclosures, the heat dissipation will become worse and the enclosures will also deform.
4. The components of switching power supply are not standardized. This is a common fault of domestic switching power supply. More than half of the market switching power supplies tested by the national quality inspection department are unqualified, including imported switching power supplies.
5. The biggest highlight is the very low lightning resistance. In the monitoring system, the possibility of encountering lightning strike is also very high, mainly from the impact of power supply, and the possibility of direct lightning strike is very low. When the voltage of 220V suddenly increases, the switching power supply will burn out instantly. In the monitoring system some time ago, the monitoring gate jumped up after thunder. After closing the gate, most of the cameras worked normally, and there was no video signal on some displays. It is detected that the power supply without video signal is switching power supply, which is inconvenient to install during construction. Finally, a power box was installed on the camera rod and the transformer power supply was replaced.
Transformer is a device that uses electromagnetic induction principle to change AC voltage. Its main components are primary coil, secondary coil and iron core. The main functions are voltage conversion, current conversion, impedance conversion, isolation, voltage stabilization (magnetic saturation transformer), etc. Power transformers and special transformers (furnace transformer, rectifier transformer, power frequency test transformer, pressure regulator, mining transformer, audio frequency transformer, intermediate frequency transformer, high-frequency transformer, impulse transformer, voltage transformer, electronic transformer, reactor, transformer, etc.) are used according to different purposes. Circuit symbols often begin with a t number. For example, T01, T201, etc.
Advantages and Disadvantages of Hengfengyou Transformer
advantage:
1. Linearly, it looks bulky, and the power falls on the transformer and regulator, which is low in efficiency but does not introduce additional interference. That is to say, the electromagnetic interference is small and the ripple coefficient is low, which can be ignored. For monitoring, there is nothing better than this advantage. The quality of the image is closely related to the power supply. Because the power supply has very high requirements for low value analog signals (such as audio source and video source), some power supplies for heating audio are transformers rather than switching power supplies.
2. The voltage stabilization rate is high, the design is simple, and the maintenance is very convenient. In case of failure, technicians who know a little about electronics can maintain, and the maintenance cost is much less than that of switching power supply.
3. Good lightning resistance. As the transformer is composed of two coils and iron core, it cannot make the voltage at both ends of the coil suddenly change, so it can strongly suppress the instantaneous high voltage. Therefore, although the power supply of the transformer survived the lightning stroke accident, the switching power supply was burnt without exception.
Disadvantages:
1. The efficiency is not high. As the transformer is a conversion process of "electricity magnetic 3354 electricity", iron loss and copper loss are unavoidable, and the efficiency is low.
2. The input range is narrow. Generally, it is only between 200V and 240V. If it is less than this range, the output voltage is not enough. If it is greater than this range, the transformer may be burnt out. This voltage range is sufficient in most cases and does not require much consideration. Moreover, the transformer is larger and heavier than the switching power supply.
You can choose according to your own needs! If you want high voltage stabilization rate and good lightning resistance, Hengfengyou transformer is your good choice.
