Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
In this case, the armature is connected in series with the field coils. Thus Ia = If = I
NB. At starting, the back emf is zero (because the motor is initially stationary) and hence the current is very large (limited only by the field and armature resistances). Hence the starting torque will be extremely large and if no load is applied (so that the torque requirement is small) the motor will accelerate rapidly to dangerously high speeds. A series connected motor must be started with a mechanical load attached to prevent the speed at start up rising to damaging speeds.Note that saturation of the magnetic material in the motor can occur at high currents and then the flux generated by the field coils becomes independent of current. This causes the characteristics to become similar to that of a shunt wound motor that also has an approximately constant field flux.
The series motor gives a high starting torque (proportional to 1/I2 ), 2.5 to 3 times the full load (rated) torque) but it falls rapidly as the speed increases. Applications: heavy duty, with intermittent starting under conditions where a mechanical load is always present - e.g. traction, cranes, hoists. etc
The speed of a series wound motor may be controlled by the addition of a resistor in parallel with the field coil. This divertssome of the current away from the field coil, reducing the field strength and hence the back emf at a given speed. The additional resistor is called a 'diverter'. The speed must increase to compensate this reduction in back emf. . Hence a reduction in the diverter resistance reduces the field strength and increases the speed of the motor.
Determine the value of maximum power: Determine the value of load resistance, R L for which the source shall transfer the maximum power. Also determine the value of maximum p
Q. Find the output voltage in terms of the input voltage? In order to illustrate the insensitivity of feedback circuits to variations of the op-amp parameters, let us consider
Q. Compare in-channel signalling with common channel signalling? Network wide signalling also involves end to end signalling between originating exchange and the terminating ex
There are three types of buses. Address bus: This is used to carry the Address to the memory to get either Instruction or Data. Data bus : This is used to take the Data from
The superposition theorem states: 'In any network made up of linear resistances and having more than single source of e.m.f, the resultant current flowing in any branch is the
When delivering rated load a 10-kW, 230-V self excited shunt generator has an armature-circuit voltage drop that is 6% of the terminal voltage and a shunt-field current equal to 4%
Can I get some ideas for power system stability simulation using Matlab?
What is meant by polling? In polling schemes, a set of address lines is driven by the controller to address every of the masters in sequence. When a bus request is received fro
Q. What do you mean by Frequency response? Now let us examine the response of a circuit to a sinusoidal source, called an oscillator, whose frequency can be varied.Known as the
To convert a galvanometer to a voltmeter, you should add a: a) High resistance in series b) High resistance in parallel c) Low resistance in series d) Low resis
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd