Loss of electromagnetic interference is the biggest problem brushless dc gear motor controller, the main reason lies in the power semiconductor devices in the process of switch, the device on the current, voltage cause at the same time. In brushless dc gear motor controller of various kinds of loss, loss produced by electromagnetic interference, after the power supply with high efficiency to a certain level will not allow to ignore. Energy consumption on the one hand, the electromagnetic interference itself, especially the improvement of power efficiency often require soft switch technology or zero voltage switch or zero current switching technologies, application of the technology of slow down the process of the switch of voltage, current changes in the rate or eliminate the switch process, electromagnetic interference is small, do not need to set as in conventional switching power supply circuit circuit to restrain electromagnetic interference. The same volume of brushless dc gear motor controller the power dissipation of basic same, therefore, to get more power output, must improve the efficiency, at the same time, high power efficiency can effectively reduce the stress of the power semiconductor devices, to improve its reliability. Brushless dc gear motor controller switch tube and the output rectifier diodes can achieve zero voltage switch or zero current switch, its efficiency can be improved obviously.
