The disadvantage of AC power supply is that the switching interference is more serious. Ac power regulation switching transistor V in the switching state of work, it produces AC voltage and current through other components in the circuit to produce spike interference and resonance interference, these interference if do not take certain measures to suppress, eliminate and shield, will seriously affect the normal work of the machine.

 

500kW load bank
 

In addition, since the AC power supply oscillator is not isolated by the power frequency transformer, these interference will be connected to the power frequency grid, causing serious interference to other electronic instruments, equipment and household appliances in the vicinity.

Due to the domestic microelectronics technology, resistance container parts production technology and magnetic material technology has a certain gap with some advanced countries, so the cost can not be further reduced, but also affect the further improvement of reliability. So in China's electronic instruments and electromechanical integration instruments, switching power supply can not be widely used. In particular, high voltage electrolytic capacitors, high back pressure high-power switching tube, switching transformer core materials are still in the research and development stage in China. In some technologically advanced countries, although the AC power supply has a certain development, but there are still some problems in the practical application, is not very satisfactory. This exposes another disadvantage of AC power supply, namely complex circuit structure, high failure rate and maintenance trouble. If designers and manufacturers do not pay enough attention to this, it will directly affect the promotion and application of power supply.