lab report ee 2

8/10/2019 LAB REPORT EE 2

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PROCEDURE

3.0 Experiments

1) All the equipments needed are set up before starting the experiment.

2) The circuits are constructed using the schematics provided. The observation is recorded foreach experiment.

Experiment 1

1) The variable resistor is used and the potentiometer of 1K is tried out.

2) The potentiometer knob is turned, while any voltage from zero to the full voltage V is picked. In this case, 5V is used.

Experiment 2

1) The resistors are tried out in various combination to make different colors.

2) Then, the potentiometers are added to the leads.

3) 5V of power supply is used.

5V

5V



Experiment 3

1) The photoresistors are used to change their resistance by the amount of light detected.

2) 5V is supplied from the power source.

Experiment 4

1) The capacitors are used, where they can provide energy, however briefly and they cansmooth out a signal.

2) The battery is attached briefly to fill the capacitor.

Experiment 5

1) A voltage regulator are made into the circuit.

2) Two capacitors are used and 9V is supplied from the power source.

5V

9V



Experiment 6

1) After the circuit is set up, the direction of the diode is changed.

2) The situation in the circuit and the condition of the motor is observed.



OBSERVATIONS AND RESULTS

Experiment 1

Resistor used : (Resistance value : 470 ohms +/-5%)

Minimum value of resistance : 0.00 Maximum value of resistance : 1.07

1) As we turn the potentiometer knob, while we pick any voltage from zero to the fullvoltage V, this circuit permits you vary the voltage to the chosen resistor with the

potentiometer, and to measure the voltage and current to it. The lower the resistance, thehigher the brightness.

Experiment 2

1) The intensity of the RGB LED changes when the 1K POT is added.

2) As RGB led contains a red, a green and a blue LED in a single pack. we can vary theresistance in the circuit by using a pot, which results in varying intensity of the particularcolour.

3) Intensity of LED changes on turning the pot knob. When the resistance varies, the LEDwith the least resistance glows with more brightness.



Experiment 3

1) Photoresistor is a resistor which has high resistance normally and very low resistance whenthere is lots of light falling on it.

2) As light falling on the LDR increases, its resistance decreases. As a result more currentflows through the LED, increasing its brightness. When you cover the LDR, its resistanceincreases. So due to high resistance, brightness of the LED reduces.

Condition ResultsLDR covered in hands No light from LEDLDR in open There is light from LED

Experiment 4

1) When the switch is closed, the capacitor is charged up for some time and then the switch isopened. There is some light from the LED with a low brightness ( as the capacitor’s charge islow ).

2) The charge is decreasing very slowly, and then a more rapid decrease as the capacitordischarges through the resistor.

3) The capacitor should remain at its present voltage, with a very slow drop over time. Thisindicates that the charge you placed on one of the capacitor plates has no way to move over

and neutralize the opposite charge on the other plate.



Experiment 5

1) In this case, we are using a LM7805, which outputs 5 volts. In order for the regulator tooutput 5 volts, the voltage entering has to be larger than the voltage that the regulatorregulates out.. However, for experimental purposes and ease of getting parts, we use a 9 volt

as our input voltage.

2) Pin 1 is the Input pin. The output voltage of whatever voltage source you want to regulatedown is fed into this pin. So, the output of the power supply is fed into the regulator input(pin 1) so that the regulator can regulate it down to our wanted voltage (5 volts). Pin 2 isGround. Without ground, the circuit couldn't be complete because the voltage wouldn't haveelectric potential and the circuit wouldn't have a return path. Pin 3 is the Output pin. This isthe pin that gives out the regulated voltage, which, in this case, is 5 volts. At the end of thisexperiment, when our circuit is hooked up, we read out the voltage and it gives out close to 5volts.

5) The first capacitor, cleans up the signal if any (ac) noise is present on this. It shorts thisnoise to ground and allows the pure DC signal into the regulator. The regulator regulates thisvoltage down to 5 volts. After it comes out of the regulator, the other capacitor, cleans up anyhigh-frequency or ac noise that may come out, again to produce a clean DC signal. Now thisDC voltage, clean and crisp, is ready to give out power whatever you want it to.

Experiment 6



1) When the direction of the diode is changed, the motor will not move and the LED do notlight up.

2) To decrease speed, the voltage supplied to the motor needs to be decreased. And toincrease speed, the voltage supplied to the motor needs to be increased.

CONCLUSION



As a conclusion, this experiment is designed fully to understand the function of basicelectrical component and recognize the components itself. The resistor is an electroniccomponent that has electrical friction. It opposes the flow of electrons in the circuit.Capacitors are components that can store electrical pressure (voltage) for long periods of

time. It has polarity, i.e positive and negative terminal marked on its sides. Potentiometers arevariable resistors and when its knob is turned, it can varies its resistance. Photoresistor is aresistor which has high resistance normally and very low resistance when there is lots of lightfalling on it. Diode is basically an electronic device that allows current to flow in onedirection only while transistor is a device that amplifies or switches the flow of current,

between its terminals (Collector and Emitter). The switching or amplification is controlledthrough Base. LED (Light Emitting Diode) is a device which emits light when powered ON,available in various colours and works only in one direction. Switch is a mechanical devicewhich opens or closes a circuit, used to turn ON or turn OFF lights and speakers.

From the experiment, we managed to construct working circuit on the breadboardfrom the schematics and at the same time, we can identified either the circuit is the open orclosed one, and either the arrangement is in series or parallel. A closed circuit has a complete

path for current to flow while an open circuit doesn't, which means that it's not functional.

During the experiment, we should have some precautions. While handling the board,we should be gentle and keep the board on a dry surface. The circuit must be checked once

before starting the experiment. We should not ever change any or make new connectionswhen power is on. As we know, the capacitors have polarity, (POSITIVE and NEGATIVE)marked on them so, do not connect 5V to NEGATIVE of the capacitor or ground to

POSITIVE of the capacitor as it will explode. Transistors have three pins( Emitter, Base andCollector). They should be connected properly as shown in the wiring diagram. RGB LEDhad 4 pins in which + pin goes to +5v and the rest 3 pins goes to resistors. For the

potentiometer, the POT should be handled very carefully using hands and the POT can’t bemoved beyond the given limit as shown below. LED also have polarity, so it must beconnected by to ways, the positive terminal to the resistor and the negative terminal toground.

Lastly, based on the experiment, basically we just focus on DC circuit and wemanaged to construct the circuit with the help of the schematics and from the results now we

are just being familiar with the behaviours and funtions of the components.

lab report ee 2

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