Three phase drive axle
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The three-phase full-bridge drive circuit of the brushless motor uses six n-channel MOSFET tubes (Q1~Q6) as power output components, and the output current can reach tens of amps when working. For ease of description, the circuit has the following default conventions: Q1\/Q2\/a3 is called the \"upper arm\" of the drive axle, and Q4\/Q5\/Q6 is called the \"lower arm\".
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Connect to a voltage doubling rectifier circuit composed of diodes and capacitors (please analyze the principle yourself) to provide the upper arm drive tube with a pull up level twice that of the power supply voltage (2×11V), so that the upper arm MOSFET has a high enough VGS pressure difference when working, and reduce the on-internal resistance of MOSFET when large current output. Please refer to MoS TUBE DataSheet for detailed data.
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The G pole of the upper arm MOS tube is respectively driven by Q7\/a8\/a9, which only plays the role of conduction commutation during operation. The lower arm MoS is directly driven by the PWM output of the MCU. Note that the selected MCU pin should have push-pull output characteristics