Brushless DC motor start circuit that suppresses field excitation during alternate polyphase commutation states when starting

摘要: During start-up a telegraph-start circuit for DC motor withholds exciting current from the stator field coils during alternative ones of polyphase commutation signals used when is running. This produces high starting torque at an initial time overcoming dead-point, head-sticking and insufficient-initial-starting-torque problems in drive applications, while avoiding rail-to-rail short-through driver circuitry. Commutation-stop power-OFF control lowers dissipation required coil circuitry by periodically interrupting flow into coils. The includes adjustable-rate clock generator, commutation-stop controller, ring counter, dual-mode circuit, circuitry, zero-crossing reference phase selector, detector, condition-of-rotation detector.