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!
Speed Control of DC Series Motor
A half wave circuit for the speed control of DC series motor is shown in figure and corresponding wave from is shown in figure consists diac and diode to give the triggering pulses to the SCR. Here SCR is used to control the armature voltage of the DC motor. By varying R2 firing angle α can be controlled of SCR. During the positive half cycle of input ac voltage capacitor C will through R1 and R2.
SCR will get turned on when the capacitor voltage Vc is equal to the addition of back emf Eb of motor and break over voltage VBO of the diac. By varying the resistance R2 the charging time of capacitor (r= R2C) hence the speed of motor can be controlled. Basically it is the armature voltage control method. In case when SCR is not conducting the armature voltage will be there due to the residual flux which is approximate proportional to the speed .
Due to the fluctuation in load will results the change in speed of motor and according back emf of the motor will change. Since the break over voltage of diac is constant and back emf is varying means the difference of Vc and ( VBO + EB) may increase or decrease as EB is increased or decreased respectively. The firing of SCR depends on this difference. As a results the average dc voltage across the armature will change and speed of motor can control accordingly.
Intel's 80386 was the first 32-bit processor, and as the company had to backward-support the 8086. All the modern Intel-based processors run in the improved mode, capable of switch
we work as a group on Automoted guided vehicles project, with 2 vehicles one is leading and the other is guided and following the first one, i was assigned to write an obstacle avo
Q. In an RLC series circuit excited by a voltage source v(t), for R = 10 , L = 1 H, and C = 0.1F, determine v(t) if the capacitor voltage vC(t) = 5e -10t V.
Q. Compare RC coupled and Transformer coupling?
A two-pole, three-phase, 60-Hz, wye-connected, round-rotor synchronous generator has N a = 12 turns per phase in each armature phase winding and flux per pole of 0.8Wb. Find the r
Discuss important properties and uses of Ceramics. Ceramics - These are materials made by high temperature firing treatment of natural clay and specific inorganic matters. The
A 25KVA, 3 phase, wye-connected, 400v synchronous generator has a synchronous impedance of 0.05 +j1.6 ohms per phase. Determine the full load voltage regulation at (a) 0.8 power
Q. (a) An ampli?er with F 0 = 3 or 4.77 dB, f 0 = 4 GHz, and BN = 14 MHz is used with an antenna forwhich T a =200K. The connecting path loss is 1.45, or 1.61 dB at a physical t
charactersticks of pn junction
Consider the following signals, sketch each one of them and comment on the periodic nature: (a) x(t) = A cos(2πf 0 t + θ), where A, f 0 , and θ are the amplitude, frequency, and
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