摘要：论文研究了一种直流无刷电机的无位置传感器的转子位置的硬件电路检测方法。结合传统“反电动势”方法，分析并设计了一种新的带通滤波器延时检测电路。该电路不仅可以抑制高频分量和消除直流分量，同时在不同的转速范围内，实现了将反向电动势的过零点移相900，弥补了过零点和换相之间的相位差问题，解决了无位置传感器的电机换相问题。论文给出了电路的仿真波形，并结合具体的直流无刷电机，给出了实际的测试波形，验证了该硬件检测电路的可行性。

关键词：滤波器；无位置传感器；反电势法；过零检测；直流无刷电机
Abstract: The paper introduced hardware detection methods for Brushless DC motor(BLDCM) without position sensors. Combining traditional "Back Electromotive Force" approach, the paper analysed and designed a new band-pass filter circuit. The circuit not only suppresses the high frequency components and eliminate the DC component, meanwhile within the different speeds, but also resolves the problem that  the phase shift is ninety degrees between the zero-crossing and phase change time. Finally the paper gave the simulation waveforms and the experiments according to the circuit parameters and a specific BLDCM.

Key words: filter；sensorless；back EMF；zero-crossing；BLDCM