The purpose of this document is to provide fundamental high-level information about the Mac OS X core operating-system architecture. It also provides background for system programmers and developers of device drivers, file systems, and netwo

客户经过量产的多功能蒸汽机（烫衣服所用），带LCD显示，多级功率可调，过流过压检测，过零检测电路和程序。-Customers through mass production of multi-functional steam engine (ironing) with LCD display, multi-level power adjustable overcurrent and overvoltage detection, zero-crossing detection circuit an

We propose a position sensorless control scheme for a four-switch, three-phase brushless DC motor drive, based on the zero crossing point detection of phase back-EMF voltages using newly defined error functions (EFs). The commutation instants are

The circuit consists of an opto-isolated zero-crossing detector and an opto-isolated trigger circuit for the TRIAC. The opto-isolators are necessary to keep the low voltage signal circuits away from the power circuits and provide an appropriate level