Tricky but Easy Electrical Engineering!
Carbon Brushes are used collect the current due to the induced emf from the armature coils in a DC Generator, as all of us know. When a brush is at any particular commutator segment, it shorts out that particular coil and draws current from the rest of the coils. If the brush is not exactly … Read more
In the last post “Need for Electrical Braking in Electrical Drives“, we discussed the various reasons which call for Electric Braking. Brakes are used to reduce or cease the speed of motors. Braking of Motor can be classified into three types: Regenerative Braking. Plugging type Braking. Dynamic Braking. In this post we will focus on … Read more
This may come in our mind that what exactly will happen if we operate a DC Motor at a speed more than the rated speed. In fact, the thermal capacity of the motor decides at what speed it can run and for how long. There is always a safety factor considered in the design which … Read more
A universal motor is a special type of motor which is designed to run either on DC or single phase AC supply. Universal Motors are so named because they can run both on AC as well as DC. A universal motor has a high starting torque and variable speed characteristics. Such motor runs at dangerously … Read more
When there is a change in magnetic flux linkage through a conducting loop, an emf is developed as per the Faraday’s Law of Electromagnetic Induction. Generators use Electromagnetic Induction to convert mechanical energy into electrical energy. In an AC, or alternating current, Generator, the electrical current periodically reverses its direction. With a DC, or direct … Read more
Servomechanism is a powered mechanism producing motion or forces at a higher level of energy than the input level, e.g. in the brakes and steering of large motor vehicles, especially where feedback is employed to make the control automatic. A servomechanism, sometimes also called Servo, is an automatic device that uses error-sensing negative feedback to … Read more
Speed control of BLDC motor is essential for making the motor work at desired rate. Speed of a brushless dc motor can be controlled by controlling the input dc voltage / current. The higher the voltage more is the speed. Many different control algorithms have been used to provide control of BLDC motors. The motor … Read more
What is a Brushless DC or BLDC Motor? A Brushless DC Motor, BLDC accomplishes commutation electronically using rotor position feedback to determine when to switch the current. The BLDC motor is electrically commutated by power switches instead of brushes. The structure of Brushless DC Motor, BLDC is shown in figure below. In simple words, a … Read more
A commutator in a DC Machine has alternate bands of Copper and mica. Now when the armature starts to rotate by an external force (in DC Generator), the coils situated in the armature also rotate. The coils are shorted via brush segment with alternate change in influence of poles. This alternate change via the commutator … Read more
As discussed in the previous post “Speed Control of DC Motor”, speed of DC Motor can be controlled by varying the terminal voltage Vt of the DC Motor. Ward-Leonard Method is the application of this principle where the terminal voltage Vtof DC Motor is varied to control the speed of DC Motor. Ward-Leonard Method of … Read more