Speed Control Of DC Motor Using PWM
Price in reward points: 9
Ex Tax: Rs. 2,200.00
Brand: Orion iTech Solutions
Product Code: SB01/EE107
Product Code: SB01/EE107
Often, people attempt to control DC motors with a variable resistor or variable resistor connected to a transistor. While the latter approach works well, it generates heat and hence wastes power. The simple Pulse Width Modulation PWM DC motor control eliminates these problems. It controls the motor speed by driving the motor with short pulses. These pulses vary in duration to change the speed of the motor. The longer the pulses, the faster the motor turns, and vice versa.
To change direction, a double pole change over switch or relay is needed to change the polarity of the applied voltage and the motor spins the other way. However, this has the disadvantage that they then a Double pole / Double throw DPDT switch has to be added to change the polarity of the applied voltage.
Therefore, there are two ways to control the motor a direction switch as well as the speed control. Also, it is not a good idea to suddenly reverse the voltage on a DC motor while it is spinning. It can cause a big current surge that could burn out the speed controller, as well as causing big electrical and mechanical stresses on the motor itself.
The current designed circuit overcomes both these problems. The direction and speed is controlled using a single potentiometer. Turning the pot in one direction causes the motor to start spinning. Turning the pot in the other direction causes the motor to spin in the opposite direction. The center position on the pot is off, forcing the motor to slow and stop before changing direction.
Q1. What is PWM?
Ans1. PWM is Pulse-width modulation (PWM) is a technique used to encode a message into a pulsing signal. It is a type of modulation.
Q2. What we use to control speed of motor and why?
Ans2. We uses 10k Potentiometer to control speed of motor because potentiometer act as a variable resistance and provide analog signal for varying speed of motor.
Q3. What is the role of 555 timer IC in this project?
Ans3. The 555 timer IC is used to generate square wave pulse of varying duty cycle according to the value of potentiometer i.e. for PWM.
Q4. What is the advantage of using PWM signal for controlling speed of motor?
Ans4. 1. The motor consumes less power
2. Significantly less energy loss due to heat
3. Allows finer motor control