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The output of a rectifier is not pure dc. The output of a Rectifier having A.C.components called ripples. To remove these ripples we are using filter circuit across it.There are following types of Filters:
Shunt Capacitor filter Series Inductor filter CLC or π filter
1. Firstly take the out put from Full Wave Rectifier2. Take the output from Shunt Capacitor filter3. Output from CLC Filter.
IC of 7815, Connecting Wires, Power Supply, Bread-Board, multimeter.
The 3 terminal IC regulators provide regulated voltage from 5 to 24V. IC 7815 provides constant+15V at the output when the input voltage may vary over some permissible range (15 to 30 V).
Function generator, Multimeter, Two stage RC coupled amplifier Kit, connecting wires.
RC coupled amplifier is a two stage amplifier in which input is given to the first stage and outputof first stage is coupled to the input of second stage through a coupling capacitor Cc, that’s whycalled RC coupled. Plot a graph between gain and frequency; we see that gain increases as thefrequency increases. At the mid frequency gain reaches maximum and constant after that thegain starts to decreases.
(1) Positive clipper means. To remove the positive half cycles of the input voltage as shown inthe fig (1) and fig (2). When positive half cycle of the input is applied to the circuit as shown infig (1) and (2) the diode becomes reverse bias in fig (1) and forward bias in fig (2). The o/p waveform of these circuit as shown with fig (1) and (2)
(2) Negative clipper means to remove the negative half cycles of the input voltage as shown fig(3) and fig (4). The positive half cycle of the input applies in the circuit fig (3) and fig (4). In fig(3) diode becomes reverse bias, the output wave. Form as shown in fig (3) and fig (4).
Clamper: - It is a circuit that places either the positive or negative peak of a signal. At a desiredlevel is known as clamping circuit. A clamper circuit adds dc component to the input signal so asto push it either on the positive side as shown in fig (5) or negative side as shown in fig (6).Whenthe circuit pushes the signal on the positive side is called negative clamper
Experimental kit, millimeters and connecting wires.
R 12 V m
C 2
V m
C 1
D 1
D 2
2 3 0 V a c
Voltage Doublers
230Vac
D4
C4
C3
D2D1
C2
C1
D3
Voltage Quadrupler
Voltage Multiplier: - It is a circuit which is used to multiply the input voltage and give outputvoltage which can be double or triple or quadruple of the input voltage applied.
Half Wave Voltage Doubler:- During +ve half cycle of i/p voltage, D1 is forward biased i.e itconducts while diode D2 is reverse biased now the condenser C1 charges to peak value ofsecondary voltage Vm. During –ve half cycle, D2 is forward biased while D1 is reverse biasedi.e. D2 conducts. Now condenser C2 is charged voltage across C2 is sum of peak supply voltage
and voltage across C1. For –ve half cycle, cover end of secondary is +ve while upper end is –ve.Now starting from bottom of transformer secondary in clockwise direction and applyingkerchiefs voltage law to outer loop.
Voltage Tripler And Quadrupler:-
During +ve half cycle, the diode D1 conducts charging C1 to Vm with polarity indicated. In thisprocess, charge on capacitor C1 voltage Vm. In this process, charge on capacitor C1 startsdischarging. In second half +ve cycle, diode D1 & D3 all forward biased and hence conduct.Capacitor will e charged to Vm when C3 will be charged.
Vc3 =Vi+Vc2-Vc1
=Vm+2Vm-Vm=2Vm
During second –ve half cycle, D2 and D4 will conduct C4 to 2Vm.
Study of input characteristics of transistor in common base configuration.
Transistor kit, Connecting Wires, 3 Multimeters.
S
mA
S VBE S VBC
32
1
S
mA
The performance of transistors when connected in a circuit may be determined from theircharacteristics curves that relate different d.c. current.The curve drawn between emitter currentIE and emitter base voltage (VEB) for a given value of collector base voltage (VCB) is known asinput characteristics for a given value of VCB. The curve is just like that of a forward bias P-Njunction, because emitter- base junction in forward bias anode is similar to P-N junction. Infigure it is seen that with the increase in VCB. It conducts better although the effect is not verysignified. This is because large collector base voltage curve the depletion is large at the collectorbase junction to deeper into the base of the transistor. Thus, regarding the difference theresistance b/w E-B and CB regions. This exist a cut in off & set a threshold voltage below whichthe emitter current is very small sustained emitter base junction of forward biased beyond theknee of characteristics (0.7 for se.& 0.3for Ge). The emitter current IE increase rapidly with thesmall increase in VCB which means low dynamic input resistance because input resistance of a
OBJECT:
APPARATUS REQUIRED:
CIRCUIT DIGRAM:
THEORY:
CHARACTERISTICS OF TRANSISTOR INCOMMON BASE CONFIGURATION
To Study Input and Output Characteristic of Transistor in Common Emitter Configuration.
Transistor Kit, Connecting Wires, 3 millimeters.
S
mA3
2
1
S
mA
S VCESVBE
Input characteristic: The curve drawn b/w the base current IB and base emitter voltage VCEfor a given value of collector emitter voltage VCE is known as input characteristic. The currentis small as long as VBE is less than the barrier voltage. When VBE is greater voltage, the curvessimilar to that of a forward biased diode. More than 95% emitter electrons and emitter holes goto the collector to form the collector current. That is why IB is much smaller (in microampere).
Output Characteristics:- It is the curve drawn b/w collector current IC and collector emittervoltage VCE for a given value of base current IB.
APPARATUS REQUIRED:
CIRCUIT DIGRAM:
THEORY:
CHARACTERISTIC OF TRANSISTOR IN COMMONEMITTER CONFIGURATION.
1. The collector current IC varies with VCE for VCE between 0 to 1v than becomegreater than become almost constant and independent of VCE. The transistors are alwaysoperating above.
2. Output characteristics of CE configuration has same slope while CB configurationhas almost – horizontal configuration.
3. In active region, for small values of base current IB the effect of collector voltageVC, over IC is small but for large values of IB this effect increases.
4. In cut-off region, small amount of collector current IC flows even when base currentIB=0. This is called ICB moderates o/p to i/p impedance ratio makes this configurationan ideal one for coupling between various transistor stages. Output characteristics areused to find DC current gain BO.
Metal oxide semiconductor field effect transistor is an important Semi conductor device and iswidely used in many circuit applications. Instead of gate diode as in FET, here gate is formed asa small capacitor. One plate of this capacitor is the gate and the other plate is the channel withmetal oxide as the dielectric. When negative voltage is applied to the gate, electrons accumulateon it. These electrons repel the conduction band electrons in the n-channel. Therefore, lessernumber of conduction electrons are made available for current conduction though the channel.The grater the negative voltage on the gate the lesser is the current, more electrons are madeavailable in the n-channel. Consequently, current from source to drain increases the followingpoints may be noted.
(i) In a MOSFET, the source to drain current is controlled by the electric field ofcapacitor formed at the gate.
(ii) Unlike the FET, a MOSFET has no gate diode. This makes it possible tooperate the device with positive or negative gate voltage.
(iii) As the gate forms a capacitor, therefore, negligible gate current flows whetherpositive or negative voltage applied to the gate. Consequently the input impedance ofMOSFET is very higher ranging from 10,000M ohm to 10,000,00Mohm.