A d.c. chopper circuit connected to a 100 V d.c. source supplies an inductive load having 40 mH in series with a resistance of 5 Ω A freewheeling diode is placed across the load. The load current varies between the limits of 10 A and 12 A. The time ratio (Ton/Toff) of the chopper is
A 220 V dc shunt motor runs at 1500 rpm at no-load. The motor is fed through a type-A chopper. If the armature resistance is 1 Ω and duty cycle of chopper is 60%, the speed of the motor when it draw a current of 20 A would be approximately equal to
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If the motor in the previous problem is driven by an active load at 1710 rpm, then the type of chopper suitable for speed control and its duty cycle for an input voltage of 250 V will be respectively
A four-quadrant chopper is driving a separately excited dc motor load. The motor parameters are R = 0.1 Ω, L = 10 mH. The supply voltage is 200 V d.c. If the rated current of the motor is 10 A with Eb = 150 V and motor is driving the rated torque, then it is operating under
A single-quadrant type A chopper is operating with the following specifications:
Ideal battery of 220 V;
on-time ton - 1 ms;
off-time foff = 1.5 ms
The ripple and form factors will be respectively given by
Match List-1 (Chopper circuit) with List-II (Characteristic) and select the correct answer using the codes given below the lists:
Codes:
Consider the following statements:
1. DC chopper can be used in both dc and ac drives.
2. For four-quadrant operation dual converter is required.
3. Output voltage from a chopper circuit depends both on load current and duty cycle
4. In a step-down source, current can be discontinuous if duty cycle is low.
Which of the statements given above are correct?
For the type-A chopper shown below, the voltage drop across the chopper when it is on is 2 volt. If the duty cycle is 0.4, then the chopper efficiency would be approximately equal to
A boost-regulator has an input voltage of 5 V and the average output voltage of 15 V, The duty cycle is
In a 110 V de chopper drive using the CLC scheme, the maximum possible value of accelerating current is 200 A, the lower limit of the current pulsation is 140 A. The ON and OFF periods are 15 ms and 12 ms respectively. Calculate the chopping frequency.
25 docs|247 tests
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25 docs|247 tests
|