Name: CABRITO, Maverick John L. Crs/Yr/Sec: BSEE 3-3 Date: July 5, 2014 Professor: Engr. Jeffrey Odtohan EXPERIMENT NO: 1 TITLE: Application of Diodes (Forward & Reverse Bias, Rectifier) MATERIALS: Breadboard 5 resistors 6 Diodes Wire Alligator Clips Cutter/Wire stripper Long nose pliers Oscilloscope Function Generator Oscilloscope Probe Multi-Tester PROCEDURE: 1.Prepare all the materials and equipment needed: 2.Cutwiresinto1-2inchesoflengthandremovetheinsulation(1cm)onbothendsusingwire cutter of a wire stripper.3.Using long nose pliers, bend the ends of cut wires and also, the ends of the resistors and diodes as well. 4.Basedonwhatyouhavediscussedonthelectures,produceormakeacircuitshowingthe diodes on forward and reverse bias. Also, make a rectifier using 4 diodes and a resistor. 5.Once done, check the connection of the Forward and Reverse Bias circuits by connecting it on a DC Source and checking the components by a multi-tester. 6.Usingtheoscilloscope,functiongeneratorandoscilloscopeprobe,checkthewaveformed.It must be half wave for the forward bias and full wave for the rectifier. DATA AND OBSERVATION: FORWARD AND REVERSE BIAS Circuit Diagram for Forward Bias Circuit Diagram for Reverse Bias Abreadboardisaconstructionbaseforprototypingofelectronics.Placingcomponentsinitwill showhowandwhatshouldbeadjustedandbemodifiedtoreduceexpendituresoftimeandeffort.For forwardbiaseddiodes,wehaveconsideredtheconditionthatthepolarityofitshouldcomplywiththe source.Forforwardbias,thepositiveterminalshouldbeconnectedontothepositiveterminalofthe source. However, for the reverse bias, the polarity of the diode is opposite the forward bias. The gray part of the diode should be connected to the positive terminal of the source. Upon doing the experiment, I have observed to different things; one is that when we have connected the circuits into the DC source and check the current and voltage using the multi-tester we have, I have seen that the forward biased circuit lets the currenttoflow.Thus,themulti-testerhasshownmovementsimplyingthatthereiscurrentflowing. However,connectingthereversebiasedcircuitontotheDCsourceanddoingthesamethingaswiththe forward bias, it has shown that there is no current flowing. FORWARD BIAS REVERSE BIAS Afterwards,usingtheoscilloscope,the forwardbiashasproducedhalfwavesasshown in the photograph. FULL-WAVE RECTIFIER Circuit Diagram for Rectifier Arectifierrequiresabitunderstandingon howitshouldbemade.Itsdifferentinmaking forwardandreversedbiasedcircuits.Fourdiodes, a resistor and a breadboard are what we will need. Takethefourdiodesandfollowtheschematic diagram as shown above. Pick two diodes; connect theirtwoendsmarkedwiththewhitebands,by insertingitonthebreadboard.Fortheremaining twodiodes,thistimewiththeirendshavingno bandsalsoconnectandinsertitontothe breadboard. And finally, insert a resistor.

Usingtheoscilloscope,attachthealligator clipsontheresistorsandonthetwoconnected diodes.Aswecheckedthewaveformed,wehave seenthatithasproducedafullwave.Thus,giving usthe ideathatwehave conductedthe experiment right. CONCLUSION: Breadboardssuredoeshelpinmakingsuchexperimentseasyandmoremanageable.Itherefore conclude that diodes do possess characteristics that help in modifying and handling such circuits. Once they are in forward biased, it puts the direction of the current in one direction just like what is its real purpose. However,puttingitinreversemakethecircuitopen,thusnocurrentisflowing.Itisbecausethereverse biased diode opposes the flow of current. Diodes allow electric current to flow in one direction. This makes them useful for many applications, including the design of circuits called rectifiers. The simplest (full wave) bridge rectifier is made up of just four diodes. These are components which allow electricity to flow in just one direction. Name: CABRITO, Maverick John L. Crs/Yr/Sec: BSEE 3-3 Date: August 2, 2014 Professor: Engr. Jeffrey Odtohan EXPERIMENT NO: 2 TITLE: Clipper and Clamper MATERIALS: Breadboard 1 Capacitor 2 Resistors 2 Diodes Wire Alligator Clips Cutter/Wire stripper Long nose pliers Oscilloscope Function Generator Oscilloscope Probe Multi-Tester PROCEDURE: 1.Prepare all the materials and equipment needed: 2.Cutwiresinto1-2inchesoflengthandremovetheinsulation(1cm)onbothendsusingwire cutter of a wire stripper.3.Usinglongnosepliers,bendtheendsofcutwiresandtheendsofthecapacitor,resistorsand diodes as well. 4.Based on what you have discussed on the lectures, produce or make a diode network of clipper and clamper. 5.Oncedone,checktheconnectionoftheclipperandclampercircuitsbycheckingthe components by a multi-tester. 6.Usingtheoscilloscope,functiongeneratorandoscilloscopeprobe,checkthewaveformed. Capture the image thatll be shown. DATA AND OBSERVATION: DIODE NETWORKS OF CLIPPER AND CLAMPER CIRCUITS Circuit Diagram for Clipper Circuit Diagram for Clamper Fortheclippercircuit,wehaveconsideredseveralconditions:Aresistorandadiodearethetwo main components of the circuit. The positive terminal of the source must be connected to the anode of the diode and the resistor is connected to the circuit in series. This is for the clipper that will show clips on the negative waves on the oscilloscope.However, for the clamper circuit, we have considered several conditions: A resistor, a diode and by this time, we needed a capacitor to make a clamper circuit. The positive terminal should be connected onto the capacitor (polarized or non-polarized) and connected to the diode and parallel to the resistor.

CLIPPERCLAMPER Afterwards, using the oscilloscope, we have connected the contacts to the inputs and outputs of the circuit. Upon doing it, we have seen waveforms. In this case, the wave formed was clipped on the negative portion. Thus, we can conclude that the circuit we have created is correct. The same thing with the clamper, however,thewaveformedshiftedeitheraboveorbelowthe0-axisyetitmusthavethesameamplitude and with no distortion.

Wave Formed by Clipper Wave Formed by Clamper CONCLUSION: Upondoingtheexperiment,Ihavegatheredseveralideasthatcomplywiththerealpurposeand definitionoftheclipperandclamper.Aclipperisacircuitthatisusedtoeliminateaportionofaninput signal.Andaclamperisacircuitdesignedtoshiftawaveformaboveorbelowadcreferencevoltage withoutalteringtheshapeofthewaveform.Anegativeclampershiftsitsinputwaveforminanegative direction, so that it lies below some dc reference voltage. A positive clamper shifts its input waveform in a positive direction, so that it lies above some dc reference voltage. Name: CABRITO, Maverick John L. Section: BSEE III-3 Date: Professor: Engr. Jeffrey Odtohan EXPERIMENT NO. 3 TITLE: Transistor as a Switch and as an Amplifier MATERIALS: Breadboard 2 resistors KSP 2222A Transistor Wire Alligator Clips Cutter/Wire stripper Long nose pliers Oscilloscope Function Generator Oscilloscope Probe Multi-Tester PROCEDURE: 1.Prepare all the materials and equipment needed: 2.Cut wires into 1-2 inches of length and remove the insulation (1cm) on both ends using wire cutter of a wire stripper.3.Using long nose pliers, bend the ends of cut wires and also, the ends of the resistors. 4.Based on what you have discussed on the lectures, produce or make a circuit showing the circuitry of a transistor used as a switch. 5.Oncedone,checktheconnectionofthecircuitbyconnectingitonaDCSourceandcheckingthe components by a multi-tester. 6.Using the oscilloscope, function generator and oscilloscope probe, check the wave formed. DATA AND OBSERVATION: Circuit Diagram of Transistor as a Switch Circuit Diagram of Transistor as an Amplifier Wave Formed by Transistor as a Switch Wave Formed by Transistor as an Amplifier Because a transistors collector current is proportionally limited by its base current, it can be used as a sort ofcurrent-controlledswitch.Aswhatwehaveseeninwaveformed,thewavehasflipped.Therearetransistors that are referred to as switching transistors due to the speed with which they can switch from one voltage level to the other. TheCommonEmitterAmplifiercircuithasaresistorinitsCollectorcircuit.Thecurrentflowingthrough thisresistorproducesthevoltageoutputoftheamplifier.Thevalueofthisresistorischosensothatatthe amplifiers quiescent operating point, Q-point this output voltage lays half way along the transistors load line. CONCLUSION: Transistors sure do make a circuit more useful. Through its characteristics, it can be used as a switch or as anamplifier.Withthehelpofseveralcomponentssuchasresistors,LED(forindicators),capacitorsandothers, you can do what you wish to have. The use of a transistor as a switch is that when acting as a switch the transistor is either: (1) off, because the base-emitter junction does not have a sufficient forward-bias voltage applied to it; or (2)saturated,becausealargebase-emitterforward-biascurrentisapplied.AndfortheamplifierAsimpleand effective way to construct a transistor gain stage is to supply the transistors base bias using a voltage divider and to capacitively couple the input and output signals.