The previous simple analysis of the need for AC DC conversion, the use of transformer mode and switching mode AC DC power supply knowledge, explained the working status and principle of the circuit diagram. The advantages and disadvantages of the power transformer mode and switching mode are described below.

Advantages of using power transformer mode:

1. Easy circuit

2. Less noise

3. Low cost

Disadvantages of using power transformer mode:

1. Increase in volume and weight

2. It gets hot

3. Poor efficiency

Advantages of using power switch mode:

1. Small size and light weight

2, not easy to heat

3. High efficiency

Disadvantages of using power switch mode:

1. Complex circuit

2. Many high-voltage components

3. Switching will produce noise

The advantages and disadvantages of the two are basically reversed. If you compare the circuit structure, you will find that there are some differences in the structure due to different conversion modes, but the circuit using switch mode is still more complex. In addition, the power switch mode must use control circuit, basically using power IC. The two use components are very similar, but the switching mode is mostly high voltage components, components specifications will affect the cost of manufacturing. The biggest difference between the two is efficiency, while volume and weight are also advantages of the switching mode.

AC DC power switch mode is to firstly DC AC input (50/60Hz) and then convert it into HIGH-FREQUENCY AC. Therefore, it can use smaller transformer and output capacitor to greatly reduce the external size. The basic working mode and the switch mode described in the previous article are after rectifying and smoothing AC input, the remaining steps are the same as the DCDC converter. The same is true with regard to efficiency. In the switching mode, since only the necessary power is deducted, the efficiency can be improved, and thus the heat can naturally be suppressed.

As for the AC DC power supply design, efficiency, size and cost must be matched, but the best method can be selected if the differences caused by different methods and the advantages and disadvantages of each method can be understood first.