What is the role of the custom-make?(3)

Input protection circuit General non-standard customization supply products use built-in filters, which can meet the requirements of general LED advertising screen power supply applications. If a more demanding power system is required, custom-make the input filter network should be added. Either LC or π can be used but care should be taken to choose a smaller inductance and larger capacitance.

Power active filter is a new type of power electronic device that can dynamically suppress harmonics. It can overcome the shortcomings of traditional LC filters and is a promising harmonic suppression method. The filter consists of a bridge switching power converter and a specific control circuit. The difference from the traditional switching power supply is: (1) not only feedback the output voltage, but also feedback the average input current; (2) the current loop reference signal is the product of the voltage loop error signal and the full-wave rectified voltage sampling signal.

In order to prevent the transient high voltage damage of the non-standard customization supply, it is recommended that the user connect the transient absorption diode to the input terminal, and cooperate with the fuse to ensure that the module is within the safe input voltage range. In order to reduce the common mode noise, Y (Cy) can be increased and several capacitors nf high frequency capacitors are generally selected. R is a fuse, D is a protection diode, and D is a transient absorption diode (P6KE series).