brushless dc motor controller mechanical brake: the main power disconnect, access to a reverse voltage, rotor quick stalling, if there is a brake in the rotor side, which can realize the mechanical brake. Brushless dc motor controller without driving voltage free line state actually does not exist, there is a motor controller tooth orientation torque, motor controller is in open state, rotation axis motor controller to be able to have a feeling a resistance. Is formed by the permanent magnet rotor and the stator magnetic circuit closed, so even in free state, the rotor is still a particular location. In addition because the brushless dc motor controller in the power generation state, although the switch tube is in the off state, but the switch tube in parallel with reverse diode, is in a state of positive to the, it is able to state power back to the power and energy feedback necessarily translate into braking torque. If the rotor speed is higher, the discharge of the power supply capacity must also be considered. General speed without consideration. So in initial deceleration phase motor controller can use more braking reduce the motor speed controller in considering the rotation of the other measures. Usually fast brake of brushless dc motor controller itself has two kinds of simple solution, one is the braking energy, one kind is short braking, braking energy is kinetic energy consumption of the motor controller on the external braking resistance, short of kinetic energy consumption braking is to put the motor controller on the stator winding of the motor controller. Apparently fever better braking energy to reduce motor controller. But short braking, don't need to make any changes to the hardware, simple is its outstanding advantages, so we focus on the short braking.