amplitude modulated waveform, Electrical Engineering

The method by which electrical signals convey information has been described.

Systems components have been selected and interfaced to enable a chosen system to perform a desired operation.

1. a) Draw an amplitude modulated waveform and describe which part of it contains the information to be conveyed.

b) List 2 advantages and 2 disadvantages in the amplitude modulated system.

2. a) Draw a frequency modulated waveform and describe which part of it contains the information to be conveyed.

b) List 2 advantages and 2 disadvantages of a frequency modulated system.

3. a) Draw a digital signal waveform and describe where the information is contained.

 b) List 2 advantages and 2 disadvantages of a digital system.

4. A domestic gas central heating system consists of the boiler, a programmer, a pump and a boiler thermostat.

 a) Draw a single block diagram to represent the system.

b) Draw a block diagram to represent the system. Include only one radiator for simplicity.

5 A strain gauge gives an output of 25 mV for a strain input of 1.8 mm/m. The transducer output is fed into a voltage amplifier with a gain of 80 and then into a moving coil voltmeter with a deflection of 20 °/V.

 a) Draw the block diagram of the system.

 b) What are the overall units of sensitivity?

c) Calculate the overall sensitivity.

d) What will be the deflection of the pointer on the voltmeter for a change in strain of 0.75 mm/m.

6. A closed loop speed control system for a dc motor is illustrated below. The electrical energy input to the motor is controlled by a low power electrical signal (Vi).

432_low power electrical signal.png

An error-actuated pre-amplifier feeds a drive amplifier, which in turn drives a dc motor. The motor speed is sensed by a speed transducer (tachogenerator) which sends a voltage signal to an error detector.

 a) Describe the purpose and operation of the Error Detector.

b) Calculate the input voltage that is required in order to maintain a motor speed of 1500 rpm for a given value of load.

c) Calculate the instantaneous change in error voltage if the load increases, causing the speed to fall instantaneously to 1200 rpm.

7. a) Describe and give diagrams of the load waveform, as to how the load energy is controlled by the control input variable in the circuit below.

1234_control input.png

 b) What might this type of energy control be used for?
 
The processing program, contained in the micro-controller, continually reads data from each of the sensors and stores this data in its memory, for later access. It also displays any data on 7-segment LED displays, on request.

8. For the system shown above:

a) Select and specify a suitable sensor or transducer for input number 1, you should provide a data sheet as an appendix.

b) Select and specify a suitable sensor or transducer for input number 2, you should provide a data sheet as an appendix.

c) Select and specify a suitable sensor or transducer for input number 3, you should provide a data sheet as an appendix.

9. a) Describe the function served by the multiplexer and demultiplexer.

b) Describe the function served by the hand shaking lines between the ADC and the micro-controller.

c) State the type, or types, of input signal conditioning required at each of the sensor outputs.

10. a) State the type, or types, of output signal conditioning required at each of the 7-segment display inputs.

b) Given that the ADC is 8-bit, and has an input analogue range of 0 to 3 volts, calculate the required gain of each sensor output amplifier used so as to maximise the accuracy of the ADC.

c) Calculate the 8-bit code at the ADC output that corresponds to an analogue input of 2.55 volts.

d) Determine the 8-bit code connected to a 7-segment LED display when it displays the value 5. Assuming the most significant bit is unused.

Posted Date: 2/22/2013 3:05:17 AM | Location : United States







Related Discussions:- amplitude modulated waveform, Assignment Help, Ask Question on amplitude modulated waveform, Get Answer, Expert's Help, amplitude modulated waveform Discussions

Write discussion on amplitude modulated waveform
Your posts are moderated
Related Questions
principle and operation of a 3phace induction motor

Explain index mode and base address mode (with examples) available in microprocessors. Index Mode and Base Address Mode: Address supplied through the instruction is adde

Explain the working principle, Surface finish, material removal, accuracy,advantages and application of Electrochemical Grinding(ECG). (a) In electro chemical machining of pure

what are the applications of thermodynamics in Electrical Engineering?

Q. Working of On - off hook circuit in telephone hand set? On/off hook circuit (sometimes termed as a switch hook) is nothing more than a simple single-throw, double-pole (STDP

Q. Explain Emergency Repairs to rail fracture? Emergency Repairs - The fractured rails shall be joined by using the arrangements clamps, fish plates. If the gap at fracture doe

i) Calculate the eigenvalues of a 100 hp, 1150 rpm dc machine at rated flux with no extra load inertia. Use the "hot" value of the armature resistance. Calculate estimates of t

How to build a 6 bit comparator?

the forward resisitance of a semi conductor diode is 10 ohm, two such diodes used in full wave rectifier subjectto a sinusoidal voltage wave form. given by v(t)=308 , sin(100 pi t)

Step Up Chopper In this  chopper average output  voltage  is greater than  input  voltage. The circuit  different  mode  of operation and  current  waveforms are show. When