On the conversion efficiency of adjustable switching power supply

As we all know, there is an important technical index in the adjustable switching power supply parameters, one of which is efficiency, but what is the specific concept of efficiency? What are its effects on switching power supplies? I believe that many customers have mentioned such a problem in their minds, but they do not seem to find the answer, let's use a simple way to answer it.

As we all know, the adjustable DC power supply mainly includes linear power supply and switching power supply two kinds, the two kinds of power supply is usually called DC current, usually the input is alternating current, output is the conversion of direct current, but the two kinds of power supply in the structure, the use of occasions are different, their main difference we will make a simple comparison, each has its own advantages and disadvantages.

First, the main advantages of linear power supply

1: no high-frequency noise interference (generally used in the environment sensitive to high-frequency signals)

2: Lower ripple voltage

3: Simple circuit structure, relatively high reliability, easy maintenance.

Two, the main shortcomings of linear power supply

1: Compared with the switching power supply, the volume and weight of the linear power supply is at least greater than or equal to the volume and weight of five switching power supplies under the same power class. The volume is bulky and difficult to transport and move.

2: Low conversion efficiency, the conversion efficiency of general linear power supply is only about 60%

3: The voltage input range is limited.

Three: the main advantages of switching power supply

1: Small size, light weight

2: High conversion efficiency, the conversion efficiency of general switching power supply is higher than 85%

3: Wide input range and compatible with AC and DC input functions.

Four: the main shortcomings of switching power supply

1: The output ripple voltage is high, generally greater than 1%

2: There is high-frequency noise interference

3: The circuit is relatively complex, high cost.

After the above comparison, I believe you have a clear concept of the difference between the two kinds of DC power supply, so we will make a solution on the conversion efficiency.

In fact, efficiency is just like people. For example, it is just like workers working in a factory with the same salary. Some people do more work while others do less work. So power is just that, just compare the two 100V100A switching power and linear power, the same power with 380V input and 100V100A output, we only use the formula to calculate the conversion efficiency, ignoring the power factor for now. Just calculate the power consumption of a 100V100A linear power supply for 10 hours, the output power =100V*100A=10000W, and if the efficiency is calculated as 70%, the power consumed per hour is 10000W/70%=14285W/H. Then we calculate the electric energy consumed within 10 hours according to this loss power: 14285W*10H=142850WH, converted into electric energy: 142850/1000=142.85 degrees.

Calculate the energy loss of 100V100A switching power supply for 10 hours, output power =100V*100A=10000W, efficiency as 85%, 10000W/85%=11764W/H, and calculate for 10 hours, 11764*10=117640W. 117640W/1000=117.64 degrees. Well, the results come out. When the two power sources work for 10 hours at the same time, the electricity rate of the linear power source is higher than that of the switching power source: 142.85-117.64=25.21 degrees, according to the current industrial minimum charge standard 1 yuan 1 degree to calculate every 10 hours of work, electricity is 25 yuan higher, then 100 hours, 1000 hours? What if there were 10 of these? Therefore, we believe that the answer has been found, so in the case of no special requirements, we generally do not recommend that customers choose linear power supply, this is the main reason.