The motor is represented by the letter M in the circuit (the old standard is D). Its main function is to generate driving torque. As the power source for electrical appliances or various machinery, the generator is represented by the letter G in the circuit. Its main function is The role is to convert mechanical energy into electrical energy.
The working principle of a DC generator is to convert the alternating electromotive force induced in the armature coil into a DC electromotive force when it is drawn from the brush end by the commutator and the commutation action of the brush.
The direction of the induced electromotive force is determined according to the right-hand rule (the magnetic line of induction points to the palm of the hand, the thumb points to the direction of movement of the conductor, and the other four fingers point to the direction of the induced electromotive force in the conductor).
The direction of the conductor's force is determined by the left-hand rule. This pair of electromagnetic forces forms a moment that acts on the armature. This moment is called electromagnetic torque in a rotating electrical machine. The direction of the torque is counterclockwise in an attempt to make the armature rotate counterclockwise. If the electromagnetic torque can overcome the resistance torque on the armature (such as resistance torque caused by friction and other load torques), the armature can rotate in a counterclockwise direction.
A DC motor is a motor that runs on a DC working voltage and is widely used in tape recorders, video recorders, DVD players, electric shavers, hair dryers, electronic watches, toys, etc.
To make the motor rotate, the control unit must determine the order of turning on (or turning off) the power transistors in the inverter (Inverter) according to the position of the motor rotor sensed by the Hall-sensor, and make the current flow in sequence. The forward (or reverse) rotating magnetic field is generated by the motor coil and interacts with the magnet of the rotor, so that the motor can rotate clockwise/counterclockwise. When the motor rotor rotates to the position where the Hall-sensor senses another set of signals, the control unit turns on the next set of power transistors, so that the circulating motor can continue to rotate in the same direction until the control unit decides to stop the motor rotor and turn off the power Transistor (or only turn on the lower arm power transistor); if the motor rotor is to be reversed, the power transistors are turned on in the reverse order.
