The isolation transformer is a safe power source, which is generally used for protection, lightning protection and filtering of machine maintenance. The primary and secondary voltages of the isolation transformer can be customized as required. First of all, the AC power supply voltage we usually use is connected to the ground by a line, and the other line has a potential difference of 220V from the earth. Human contact can cause electric shock. The secondary of the isolation transformer is not connected to the earth, and there is no voltage between any two wires and the earth. So when people get an electric shock, this is relatively safe. Secondly, the output of the isolation transformer is completely "opened" from the input, which effectively acts as a good filter for the input of the transformer (the supply voltage supplied by the grid). This provides a clean supply voltage to the consumer.