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What does turns of a model dc motor mean when refering to electronic speed controller of a brushed motor ie a certain manufacturer of an ecs states that the brushed motor must have less than 12 turns?
The number of turns of wire on the armature of the motor
What the counter emf of a motor is always less than applied armature voltage.explain?
The counter electromotive force (counter EMF) of a motor is always less than the applied armature voltage because the motor requires a certain amount of voltage to overcome its internal resistances and inductances, as well as to produce torque. When the motor starts, the armature current is high, leading to a significant voltage drop due to resistance. As the motor speeds up, the counter EMF increases, but it never reaches or exceeds the applied voltage, as some voltage is always required to maintain current flow and overcome losses like friction and heat. Thus, the counter EMF is always a fraction of the applied voltage.
A 220volts series motor takes 15amperes and runs at 700rpm the armature resistance of the series winding is 0.8 ohms at what speed will it run if resistance is connected in series with supply voltage?
It will run slower because the resistance in series with the motor will take some of the voltage and thereby reduce the current to the armature windings (less magnetic field).
Which the effect of the increase of the armature voltage on the speed of a direct-current separately excited motor in case of constant load?
Increasing the armature voltage would increase the speed. In a separately excited dc motor the speed adjusts so that the back emf generated by the armature is a little less than the supply voltage. The difference, divided by the resistance, gives the current drawn, which is also proportional to the shaft torque supplied to the load.
Why the armature of a dc motor draws more current at the time of starting?
With increasing torque load the armature tends to slow down; the motor draws more current to compensate, and if there is armature resistance the back emf generated by the armature falls to allow the increased current to flow, which causes the motor to settle at a lower speed. The mechanical output power is the speed times the torque, and increasing the torque increases the power output provided the speed does not drop much.
Why armature resistance is less than 1 Ohm?
why armature resistance is very low as compare to field resistance in dc motor
Why speed is decreased when field current increases in dc motor?
Because with more field, the armature produces the same voltage at less speed. The voltage generated by the motor must always be less than the supply voltage. A motor that is driven faster than it wants to go becomes a generator.
What is difference between stab shunt dc motor and shunt dc motor?
A series motor respond by decreasing its speed with small increase in current for a given load torque. A shunt motor holds its speed nearly constant with large increase in input current for same amount of load torque
What are the differences between the parts of a generator and the parts of a motor?
In principle a generator is the same as a motor. In a dc motor the voltage generated by the rotating armature is slightly less than the supply voltage which causes power to flow in from the supply. If an engine is then coupled to the shaft causing it to rotate faster, then it generates more voltage and power flows back into the supply. That is how a motor becomes a generator.
What does turns of a model dc motor mean when refering to electronic speed controller of a brushed motor ie a certain manufacturer of an ecs states that the brushed motor must have less than 12 turns?
The number of turns of wire on the armature of the motor
What the counter emf of a motor is always less than applied armature voltage.explain?
The counter electromotive force (counter EMF) of a motor is always less than the applied armature voltage because the motor requires a certain amount of voltage to overcome its internal resistances and inductances, as well as to produce torque. When the motor starts, the armature current is high, leading to a significant voltage drop due to resistance. As the motor speeds up, the counter EMF increases, but it never reaches or exceeds the applied voltage, as some voltage is always required to maintain current flow and overcome losses like friction and heat. Thus, the counter EMF is always a fraction of the applied voltage.
A 220volts series motor takes 15amperes and runs at 700rpm the armature resistance of the series winding is 0.8 ohms at what speed will it run if resistance is connected in series with supply voltage?
It will run slower because the resistance in series with the motor will take some of the voltage and thereby reduce the current to the armature windings (less magnetic field).
How do you measure the resistance of a motor?
we can measure the resistance of the motor by using voltmeter ammeter method of by directly using a multimeter across the armature terminals of the motor in voltmeter ammeter method we should use a less value of dc voltage to find the resistance
What is the Significance of back emf in dc motor?
Fig. (4.3)ZN/60 A) is large and hence the motor will draw less armature current and vice-versa.4.4 Significance of Back E.M.F.The presence of back e.m.f. makes the d.c. motor a self-regulating machine i.e.,it makes the motor to draw as much armature current as is just sufficient todevelop the torque required by the load.Armature current,abaREVI−=(i) When the motor is running on no load, small torque is required toovercome the friction and windage losses. Therefore, the armaturecurrent Iais small and the back e.m.f. is nearly equal to the appliedvoltage.(ii) If the motor is suddenly loaded, the first effect is to cause the armature toslow down. Therefore, the speed at which the armature conductors movethrough the field is reduced and hence the back e.m.f. Ebfalls. Thedecreased back e.m.f. allows a larger current to flow through thearmature and larger current means increased driving torque. Thus, thedriving torque increases as the motor slows down. The motor will stopslowing down when the armature current is just sufficient to produce theincreased torque required by the load.(iii) If the load on the motor is decreased, the driving torque is momentarilyin excess of the requirement so that armature is accelerated. As thearmature speed increases, the back e.m.f. Ebalso increases and causesthe armature current Iato decrease. The motor will stop acceleratingwhen the armature current is just sufficient to produce the reduced torquerequired by the load.It follows, therefore, that back e.m.f. in a d.c. motor regulates the flow of armature current i.e., it automatically changes the armature current to meet theload requirement
Which the effect of the increase of the armature voltage on the speed of a direct-current separately excited motor in case of constant load?
Increasing the armature voltage would increase the speed. In a separately excited dc motor the speed adjusts so that the back emf generated by the armature is a little less than the supply voltage. The difference, divided by the resistance, gives the current drawn, which is also proportional to the shaft torque supplied to the load.
The armature of DCgenerator is laminated to?
Reduce the eddy current less
Why the armature of a dc motor draws more current at the time of starting?
With increasing torque load the armature tends to slow down; the motor draws more current to compensate, and if there is armature resistance the back emf generated by the armature falls to allow the increased current to flow, which causes the motor to settle at a lower speed. The mechanical output power is the speed times the torque, and increasing the torque increases the power output provided the speed does not drop much.
