Switching Power Supply

power supply is to use the circuit to control the switch tube to conduct high-speed on and off. Convert DC into high-frequency AC and provide it to the transformer for transformation, thereby generating one or more sets of voltages required! The reason for converting to high-frequency AC is that the efficiency of high-frequency AC in the transformer transformation circuit is much higher than that of 50Hz. Therefore, the switch transformer can be made very small, and it is not very hot when working! The cost is very low. If 50Hz is not converted to high frequency, then switching power supplies is meaningless. ac dc converter can be roughly divided into two types: isolation and non-isolation. The isolation type must have a switching transformer, but the non-isolation type may not necessarily have one. The working principle of high efficiency industrial switching power supply is: 1. The AC power input is rectified and filtered into DC; 2. The switch tube is controlled by a high-frequency PWM (pulse width modulation) signal, and the DC is added to the primary of the switching transformer; 3. The secondary of the switching transformer induces a high-frequency voltage, which is supplied to the load after rectification and filtering; 4. The output part is fed back to the control circuit through a certain circuit to control the PWM duty cycle to achieve the purpose of stable output. When the AC power is input, it usually passes through something like an oscillator to filter out the interference on the power grid, and also filters out the interference of the power supply to the power grid; When the power is the same, the higher the switching frequency, the smaller the size of the switching transformer, but the higher the requirements for the switching tube; The secondary of the switching transformer can have multiple windings or one winding has multiple taps to obtain the required output; Generally, some protection circuits should also be added, such as no-load and short-circuit protection, otherwise the switching power supplies new original warehouse may be burned.