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.
Calculate the monthly electric bill for TESTU. Metering is as follows: B 00,000 kWHr C 00,000 kVARHr D 0,000 kW peak demand Facilities Charge = $500
Partial derivatives - Transistor hybrid model: The partial derivatives are taken by keeping the collector voltage or base current constant as pointed out by the subscript atta
Give the names of four alloys along with their composition, which are used for making heater and thermocouple elements. Constantan or Eureka {(55 to 60 percent) Cu, (45 to 40 p
Merits: 1. It is very simple to shift the operating point anywhere in the active region by just changing the base resistor (R B ). 2. A very small number of compon
Explain the properties and application of glass. Glass: Ordinary glass is a fine insulator but is too brittle to be used for anything although scientific instrument parts, accu
Voltage Quadrupler : A voltage quadrupler circuit is shown in fig. which provides output voltage V0 = 4 Vm. Operation : Capacitor C 1 , C 2 and C 3 charges to Vm, 2Vm and 2Vm
Define the X-NOR or Exclusive-NOR Gate? This is the EX-OR gate with the output inverted, as shown by the 'o' on the output and the output Q is true if inputs A and B a
Vee vcc
what are the difference between digital and Analog storage oscilloscope ?
why armature lamination notched in outer periphery
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