Developers must understand the concept of switching power supply (features of the Power Supply Module)

Developers must understand the concept of switching power supply (features of the Power Supply Module)

 

1. Concept of switching power supply

The switching power supply (Power Supply Module) is an energy converter. As a power supply, the power device works in the switch (switch, inductor, high-frequency transformer, capacitor, and rectification diode)-on or off status, it features high frequency, low power consumption, high work efficiency, small size, and wide input range (switching regulator -- a switching circuit that operates in a closed loopsystem to regulate the power supply output) the output voltage remains stable through closed-loop system adjustment.

We usually divide the type (topological structure) of the switching power supply according to the conversion method of the power converter ), there are anti-Exciting, single tube positive, double tube positive, push-pull, half bridge, full bridge, we currently use the anti-exciting and single tube positive.

2. Comparison of switching power supply, linear power supply, and phase-Controlled Power Supply

 

① Linear Power Supply: the main characteristic of linear power supply is that the power device is working in the amplification State, which has the advantages of high stability, good reliability and low cost, but is inefficient, bulky, and bulky. Only medium and small power supply can be implemented.

 

② Phase-controlled power supply: the voltage regulator is achieved by controlling the conduction angle of the thyristor. the power factor is relatively low, the efficiency is low, the power is heavy, and the size is large.

 

3. swiching-mode power supply)

The switch power supply is full of our daily life because of its small size and high efficiency, from the charger of the mobile phone to the power supply of our color TV and audio and video; from the neon lights on the side of the road, the electronic display cards at the station all use the switch power supply. From our desktop computer to portable laptop computer, these are inseparable from the switch power supply. The power supply module is a type of switching power supply. It has the advantages of small size, high conversion efficiency, and more stable performance. More and more applications are applied to modern electronic technology, also known as the module power supply. Is currently the main direction of power development, smaller, more efficient, more stable ----

 

High Integration, higher efficiency, and more powerful functions are currently the main development direction of Power Supply Modules

 

Of course, the input of the switching power supply is not limited to AC (AC/DC power supply), but also DC (DC/DC power supply and DC/AC power supply ). The AC input voltage range of the switch power supply is relatively wide, from a few volts to thousands of volts. At present, there are two kinds of control methods for the switching power supply: Pulse Width Modulation and frequency modulation (pulse frequency modulation-PFM ). The pulse width modulation-PWM method is common.

4. Main Indicators of switching power supply

 

① No fault running Interval

This is the most important indicator of the switching power supply, measuring the working reliability of the switching power supply. Generally speaking, the longer the average running interval of the switch power supply without fault, the better.Module Power SupplyAnd has been well applied in industrial applications.

 

② Work Efficiency

The ratio of the output power to the input power is the efficiency of the switching power supply, which measures the loss of the switching power supply, that is, the efficiency is

 

③ Voltage Adjustment Rate

The percentage of output voltage variation and unit output power supply and input voltage variation while the load remains unchanged. SV = (△v0 then V0 △vi) %. This parameter indicates the voltage regulation feature of the power supply.

 

④ Load Adjustment Rate

It refers to the changes in the output voltage caused by changes in the output load.
SL = (△v0 then V0) %.

⑤ Output Ripple (Peak-peak)

This indicator measures the electromagnetic compatibility of the switching power supply. The smaller the ripple, the better. Generally less than 1% volts of the output voltage. For example, for a 5 V voltage, the Output Ripple is 50 mV in position.

 

Developers must understand the concept of switching power supply (features of the Power Supply Module)