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MULTIVIBRATOR ASTABLE

ICP PHYSICS 12PHYSICS DEPARTEMENT OF FMIPA UNMABOUT MENAME: DWI MARYANTI PUTRINICK NAME: PUTEBIRTH DATE: 20th JANUARY 1996ADDRESS: JL. BORONG RAYAFROM: SENGKANGE-MAIL: dwimaryantiputri@gmail.com PHONE : 085366284166

In digital systems, timing is very considered. Multivibrator is a circuit that can generate a continuous signal, which is used as a timer of digital sequential circuits. With the input clock generated by a multivibrator, series such as counters, shift registers and memory to perform its function properly. Based on the shape of the output signal is generated, there are three kinds of multivibrator: Multivibrator bistable, Multivibrator astable, Multivibrator monostable .INTRODOCTIONPROBLEM STATEMENTRelationship pulse frequency generated from t1 (time on red light) and t2 (time on white lights)?How to compare the character of some types of capacitor?

PURPOSESStudents are expected to find relationships frequency pulses generated from t1 (times on red light) and t2 (times on white lights)Students are expected to compare the character of some kind of capacitor

THEORYMultivibrator is a cluster that emit a beam or pulse shape voltage. Actually multivibrator amplifier transistor is connected to two levels where the output from the last level of the amplifier is connected to the first, so that both transistors will mutually feedback. Astable multivibrator is one type of multivibrator which shook free (free running) and ignited (triggering). (Anonim b, 2014)

Figure 1.1 Multivibrator Serries

Charging time (high output):t1 = 0.693 (RA + RB) CAnd release time (low output):t2 = 0.693 (RB) CTotal period:T = t1 + t2 = 0.693 (RA + 2RB) CEXPERIMENT METHODSExperiments have been done by using a flip-flop circuit (astable multivibrator), which makes the flip-flop 2 transistor has two conditions interchangeably between cut-off and saturation are on the second RC circuit transistor.

APPARATUSThe connecting cable: 6 pieces

Flip-flop circuit: 1 pieceThe capacitor (100 F, 470 F, 47 F): 6 pieces

HP: 2 piecesPower supply: 1 pieceVARIABLE IDENTIFICATIONChanged variables:Capacitance capasitor (C) in units of microfarad (F). Response variables: time (t) in the second unit. Control variables: the resistor (R1, R2) in units of ohms () and input voltage (Vi) (volt)

DEFENITION OPERATIONAL VARIABLEThe capasitance capacitor C is a variable that is manipulated by replacing capacitors used 1000 F, 470 F, 220 V, 100 F, and 47 F.T the time it takes each LED during one oscillation at the right time and the right will be extinguished flaming (t1 and t2).Resistance resistor (R1, R2) is a variable control used to inhibit the amount of charge that goes to the circuit, the resistor used is 10 k.

WORK PROCEDURESEnsuring that the tools used in the lab are all in good condition.Connect the capacitor 1 with a capacitance of 100 F in the circuit, and then turn on the flip-flop and observe the indicator light by calculating the time it takes good at the right time and the right will light would die each 20 data.Repeating activities 2 with different capacitance capacitors.

WORK PROCEDURESAfter that, connect the circuit with an oscilloscope to see the waves generated and viewed amplitude waveNoting the observations in the table below.

EXPERIMENT RESULTS

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DATA ANALYSIS

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DISCUSSIONSIn this experiment used three types of capacitor which each frequency is calculated, based on the theory, the frequency is 0.15 F to 470 Hz, 100 Hz was 0.72 F, and 47 F is 1.54 Hz frequency while based practices for capacitors to 470 F capacitor is 0.18 Hz red LED with 23.56% diff percent and 0.18 percent white LEDs with a big diff 24%, to 0.84 F capacitor 100 Hz LED red with 12.17% diff percent and 0 , 81 white LEDs with a large percent of diff 11.44%, and to 47 F capacitor is 2.6 Hz red LED diff with 5.52% percent and 2.56 percent with a large green LED 1.94% diff.

DISCUSSIONSIn the measurement of smaller percent diff obtained the more accurate the data obtained, as mentioned earlier above for the capacitor 470 F percent diff very large, this is due to the difficulty set time is needed for the LEDs do one oscillation, since the turn of the flame LED bias hardly observed, therefore praktikan difficult to determine when the stopwatch should be stopped.

CONCLUSIONSFrequency pulses are generated consisting of t1 and t2 whose condition of each other.The greater the value of the capacitors used the longer time is needed LED to light up or go out back.

REFERENCESAnonim a http://fendyhananta.wordpress.com/2012/12/05/astable-multivibrator-pengendali-sinyal-digital/Anonim b http://elektronika-dasar.web.id/teori-elektronika/astabil-multivibrator/Ahmad Jayadin.2007. Elektronika Dasar. Jakarta.Malvino. A.P . 2003. Prinsip-Prinsip Elektronika, Buku 1. Jakarta : Salemba Teknika.

THANKS FOR ATTENTION