SHOPEE COMPRAR AGORA
A lot of Engineering projects and tutorials for the students to help them in their final year projects and semester projects.
The torque and speed vary with load as indicated by this torque-speed curve. Looking at the graph below, let’s consider a motor rotating at speed ω0 with torque T0.
A controller of a brushed DC motor manages the speed and torque of the motor by regulating the current and voltage injected into it. The major design and working principles of BDC motor controllers can differ between their types.
Figure 3: The changing resultant flux continually pulls the rotor magnet, causing the rotor to turn.
Due to this reduced voltage the motor speed even decreases further. This decrease in speed with duty cycle continuous to happen until a point, where the motor terminal voltage will not be sufficient to turn the motor.
A DC motor combines mechanical and electrical subsystems. The electrical part is an armature coil with a resistance and inductance to drive a field causing motion.
By closing high-side and low-side switches in a diagonal pattern, the motor rotates in one direction. The rotational direction will change as soon as these switches are open and the opposite switches are closed.
In this article, I will describe one last experiment that involves a DC motor. We will connect an ultrasonic distance sensor in the place of the potentiometer, and use that to control the rotational speed of the motors.
Once the distance is calculated, the move_motors function is called, and the distance is passed as an integer parameter. Just like in Demo 2 Version 2, motors are moved in one of two ways: if distance is 50cm or less, the motor speed is proportional to the distance.
Here’s the final appearance of the board and what’s left now is to connect a DC motor and a suitable power supply for it.
We’ll have to do this step just to have the TIM_HAL files added to our project by CubeMX. And also it gives us a startup configuration for the PWM channel of that specific timer module as we’ll see hereafter. This is the best way to keep the code generic and portable to any STM32 microcontroller.
The PWM controller accepts the control signal and adjusts the duty cycle of the PWM signal according to the requirements. PWM waves with various duty cycle are shown in the figure below.
However, in case the PWM frequency is too high, the MCU may have problems with generating PWM signals of the required value. In addition, the very high frequency may lead to the malfunction of the gate driver and transistor switches as they may not be compatible with it.
There will always be a moment when all the transistors are open. It may lead to voltage and power loss, or even short-out if the opposite upper and lower switches are in the on position.
SHOPEE COMPRAR AGORA