A rotary variable differential transformer has a specification which includes the following information:?
Ranges: ±30º, linearity error ±0.5% full range ±60º, linearity error ±2.0% full range;Sensitivity: 1.1(mV / V input) / degree;Impedance: primary 750 Ω, secondary 2000Ω;What will be (i) the error in a reading of 40º due to non-linearity when the RVDT is used on the ±60º range, and (ii)what's the output reading at 40º?
What is the difference between a squirrel cage motor and a wound-rotor (slipring) induction motor?
Squirrel Cage Induction Motor :In Squirrel cage induction motors the rotor is simplest and most rugged in construction.Cylindrical laminated core rotor with heavy bars or copper or aluminium or alloys are used for conductors.Rotor conductors or rotor bars are short circuited with end rings.Rotor bars are permanently short circuited and hence it is not possible to connect external resistance in the circuit in series with the rotor conductors.Cheaper cost.No moving contacts in the rotor.Higher efficiency.Low starting torque. It is 1.5 time full load torque.Speed control by rotor resistance is not possible.Starting current is 5 to 7 times the full load.Slip ring (wound rotor) Induction Motor :In slip ring induction motors the rotor is wound type. In the motor the slip rings, brushes are provided. Compared to squirrel cage rotor the rotor construction is not simple.Cylindrical laminated core rotor is wound for as the number of poles of the stator.At starting the 3 phase windings are connected to a star connected rheostat and during runningcondition, the windings is short circuited at the slip rings.It is possible to insert additional resistance in the rotor circuit. Therefore it is possible to increase the torque ( the additional series resistance is used for starting purposes).Cost is slightly higher.Carbon brushes, slip rings etc are provided in the rotor circuit.comparatively less efficiency.High starting torque. It can be obtained by adding external resistance in the rotor circuit.Speed control by rotor resistance is possible.Less starting current.For more info visit :https://www.electrikals.com/prod...
What is spring charging of circuit breaker?
A operating Mechanism is required to Open or Close of a Circuit Breaker. it may be a Hand operated or motorized.This mechanism simultaneously Open or close all the 3 or four terminals of a circuit breaker. In it Springs are required to provide a necessary force to these mechanism for open or close of a circuit breaker.Spring Charging means to expand it by manually or by a motor to get a necessary force.A spring charged motor mechanism is most popular. It consists a separate springs for Opening and Closing. You can see the below image for reference:Img. Source :Google.