What are characteristics of dc motor?

Generally, three characteristic curves are considered important for DC motors which are, (i) Torque vs. armature current, (ii) Speed vs.armature current and (iii) Speed vs. torque.

What is the characteristics of DC?

The fundamental characteristic of a DC signal is the absence of changes in polarity. If you connect a DC voltage signal to a resistor, the resulting current will always flow in the same direction. The magnitude of the current may exhibit large variations, but the direction does not change.

What are some useful characteristics common to DC motors?

There are two primary advantages to DC motors: Speed Variation and Torque.

What are the characteristics of DC generator?

Characteristics of DC Generators

Which of the following is mechanical characteristics of DC motor?

The mechanical characteristics of motor are the torque-speed characteristics, because it reflect relation of torque T and speed n when motor operating.

How the characteristic of DC series motor differs from DC shunt motor?

In a DC shunt motor, the armature and field (shunt) windings are connected in parallel. … In contrast, for a series-wound DC motor, torque increases as the square of armature current. This exponential torque-current relationship allows series-wound DC motors to provide high starting torque and handle high startup loads.

What are the characteristics of a cumulatively compounded DC motor?

All the characteristics of the compound motor are the combination of the shunt and series characteristic. Cumulative compound motor is capable of developing large amount of torque at low speeds just like series motor. However it is not having a disadvantages of series motor even at light or no load.

What are the characteristics of a separately excited DC generator?

The external characteristic of the separately excited DC generator is obtained by subtracting the drops due to ohmic loss (Ia Ra) in the armature from generated voltage (Eg). Terminal voltage(V) = Eg – Ia Ra. This curve gives the relation between the terminal voltage (V) and load current.

What is the advantage of DC motor?

DC motors offer highly controllable speed. By changing the armature or field voltage it’s possible to achieve wide speed variation and with this level of controllability, DC motors offer the precision required by a wide range of industry applications.

What are the advantages and disadvantages of DC motor?

DC motors have a high initial cost. Maintenance cost is high and increased operation due to the presence of brushes and commutator. Due to sparking at brush DC motors cannot operate in explosive and hazardous conditions. As the speed increases, the shaft gets vibrated and the armature gets damaged.

What is the function of DC motor?

A direct current (DC) motor is a type of electric machine that converts electrical energy into mechanical energy. DC motors take electrical power through direct current, and convert this energy into mechanical rotation.

What is external characteristic in DC generator?

AC curve is showing the external characteristic of the shunt wound DC generators. It is showing the variation of terminal voltage with the load current. Ohmic drop due to armature resistance gives lesser terminal voltage the generated voltage.

Which of the following characteristics of a DC generator is called Regulation curve?

Eg can be determined by subtracting the drop due to demagnetizing effect of armature reaction from no-load voltage (E0). So that internal characteristic curve lies below the O.C.C. curve. This type of characteristic is also called an armature characteristic or regulation curve.

What is the characteristics of motor?

Torque-speed Characteristics of Motors. The amount of torque produced by a motor generally varies with speed. This Torque-Speed characteristic depends on the type and design of a motor, and is often shown on a Torque-Speed graph.

What are the mechanical and electrical characteristics of DC shunt motor?

Characteristics of a DC Shunt Motor:

Which one is called as mechanical characteristics?

Some of the typical mechanical properties of a material include: Strength. Toughness. Hardness.

How does DC motor differ from DC generator in construction?

The most significant difference between DC motor and DC generator lies in the conversion mechanism. DC motor converts electrical energy into mechanical energy whereas DC generator converts mechanical energy into an electrical energy.

What is difference between shunt and series?

A series regulator is connected in series with the load to stabilize the regulator’s output voltage. A shunt regulator, on the other hand, is connected in parallel to the load to stabilize the device’s output voltage.

What is the principle of DC shunt motor?

The working principle of a DC Shunt Motor is, whenever a DC motor is turned ON, then DC flows throughout stator as well as the rotor. This current flow will generate two fields namely pole as well as the armature.

What is a characteristic of a compound motor?

A compound-wound motor has both a series and a shunt field winding, (i.e. one winding in series and one in parallel with the armature circuit), by varying the number of turns on the series and shunt windings and the directions of the magnetic fields produced by these windings (assisting or opposing), families of (c/s) …

Which DC motor is preferred for elevator?

DC cumulative compound motor having high starting torque up to 450% depending upon the degree of compounding. The speed regulation is varying up to 25 ~ 30%. That’s why these motors are used in elevators.

What is the characteristics of the polarity of the Interpole in a DC generator?

For generator, the polarity of Interpoles must be same as that of main Pole ahead of it in the direction of rotation. For Motor, the polarity of Interpole must be same as that of Main Pole behind it.

What is load characteristics of DC shunt generator?

Load characteristic essentially describes how the terminal voltage of the armature of a generator changes for varying armature current Ia. First at rated speed, rated voltage is generated across the armature terminals with no load resistance connected across it (i.e., with S opened) by adjusting the field current.

What is the no load characteristic of DC generator?

The no-load characteristics of a dc series generator are similar to the no-load characteristics of a shunt generator. But, at no-load condition, the generator is running at a constant speed due to series connection no field current flows as the load current IL, is zero.

What are the advantages and disadvantages of DC?

For the same value of voltage insulating materials on dc lines experience less stress as compared to those on ac transmission lines. A dc line has less corona loss and reduced interference with communication circuits. There is no problem of system instability so common in ac transmission.

What are the advantages and disadvantages of AC and DC motors?

AC motors are generally considered to be more powerful than DC motors because they can generate higher torque by using a more powerful current. However, DC motors are typically more efficient and make better use of their input energy.