PART7 Amplifier Circuit(Transistor AMP)

Experiment 1 : Amplifier Biasing

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PART7Amplifier Circuit(Transistor AMP)

Experiment Purpose

  • 1.Investigate characteristics of Amplifier Biasing.
  • 2.characteristics of Complementary AMP through experiment.
  • 3.Investigate characteristics of Common Emitter AMP through experiment.
  • 4.Investigate characteristics of Darlington AMP through experiment.
Fig. 7-1AReS-EO-M07 Transistor AMP Module

Experiment 1 :Amplifier Biasing

Theory

In common emitter composition, the current gain β of the transistor can be defined as below.

=(∆I_C)/(∆I_B )(V_CE const)

The bias conditions of β gained here are as below.

  • Emitter-base junction is forward bias.
  • Collector-base junction is reverse bias.

fig7-2

Fig. 7-2Emitter Earthing Amplifier of NPN Transistor

Transistor AMP is used for amplifying DC or AC current or voltage. Faig. 7-2 is the circuit of NPN transistor where the emitter is connected as earthed AC amplifier. R1 and R2 are used for forward biasing of base-emitter circuit. Vcc supplies power voltage for R1 and R2, which are the distributor of the collector current and base bias voltage. Input signal Vin is connected to the base through C1. In the experiment for the transistor characteristic, it is known that small increase of base current brings relatively big increase of collector current. Also, small decrease of base current causes relatively big decrease of collector current. Therefore, the currents of base and collector circuit are of same phase. In emitter common circuit, the degree of collector current depends on β of transistor.

Way of Biasing and Stabilization

To amplify without distortion, the base should be biased properly so that the input signal is operated within the linear area of transistor characteristic. Otherwise, the output is operated in cutoff or saturation area so it is distorted. That is, according to the way of transistor biasing, the fidelity of output signal following the input signal.

Experiment Process

fig7-3

Fig. 7-3Amplifier Biasing Circuit
tab1

Experiment 7-1.1 Measuring Amplifier Biasing (In Circuit-1 of M-07, compose a circuit as in fig. 7-3.)

Fig. 7-3 Circuit (a)

1.Connection(Circuit-1 of M-07)
1.Circuit Connection

Connect between 1h terminal and 1j terminal of Circuit-1 with yellow line.

2.Power Connection

It is connected internally

3.Measuring Instrument Connection

Ammeter Connection for DC Amplification Degree

Measure by using the current measurement function of separate Digital Multimeter.

Measuring the current(IB) flowing on Q1 base: Connect the red line of Digital Multimeter to 1f terminal of Circuit-1 and the black line to 1o terminal.

Voltmeter Connection for DC Amplification Degree

Measuring the voltage(VR3) of R3’s both ends: Connect between 1d terminal of Circuit-1 and High terminal on the front panel of Multimeter with red line, and between 1e terminal and Low terminal with black line.

Voltmeter Connection for AC Amplification Degree

Measuring input voltage: Connect between 1a terminal of Circuit-1 and A+ terminal of Signal Input CH A on the front panel of Multimeter with red line, and between 1b terminal and A- terminal with black line.

Measuring output voltage: Connect between 1k terminal of Circuit-1 and B+ terminal of Signal Input CH B on the front panel of Multimeter with red line, and between 1l(1n) terminal and B- terminal with black line.

2.Wiring Diagram

1) Wiring Diagram for DC Amplification Degree Measurement

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2) Wiring Diagram for AC Amplification Degree Measurement

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3.Measurement
  1. 1DC Amplification Degree Measurement

    Compose as in 2. Wiring Diagram> 1) DC Amplification Degree Measurement.

    Choose multimeter at the left menu of Touch LCD panel and choose dcv.

    Adjust variable resistance R2 and make VR3 as 4.7V, and record the values of base current(IB) on the separate Digital Multimeter in the relevant columns of table 7-1.

    DigitalMultiMeter

  2. 2AC Amplification Degree Measurement

    Compose as in 2. Wiring Diagram> 2) AC Amplification Degree Measurement.

    In 3) Measuring Instrument Connection>Ammeter Connection, remove the measuring measurement lead wire of Digital Multimeter between 1f and 1o terminal of Circuit-1 and connect them with yellow. line.

    Remove the connection wire for 3) Measuring Instrument Connection>Voltmeter Connection>Measuring the voltage(VR3) of R3’s both ends.

    Plug in BNC cable to Signal Output and connect red lead wire to 1a terminal, and black lead wire to 1b terminal.

    Choose signal output on the left of front panel, click Function Generator and set up Amplitude Range as 200mVpp, Amplitude as amplitude 10 , Frequency as 1k , Signal as sine and click on to output 1kHz 20mVpp.

    FunctionGenerator

    Click signal input on the front panel and set up the Oscilloscope screen to show input/output wave form.

    Oscilloscope

    Click quick launch on the left bottom of the screen, choose Analog Output and click arrow right at 10% to increase output voltage. Increase it until the signal wave form of CH B is not distorted, draw the wave form of Oscilloscope, calculate input voltage of CH A and distortionless output voltage of CH B and record it in the relevant column of table 7-1.

    AnalogOutput Function

    Oscilloscope

    VoltAndAmpereMeter

  3. 3Measure the amplification degree when IC is 1.25mA, 1.5mA, 1.75mA.

    Execute 1)DC Amplification Degree Measurement, 2) AC Amplification Degree Measurement and record the result in the relevant column of table 7-1. The wire connection for 1) DC Amplification Degree Measurement 3) Measuring Instrument Connection>Ammeter Connection and 3) Measuring Instrument Connection>Voltmeter Connection>Measuring the voltage(VR3) of R3’s both ends.

    Adjust the value of IC as 1mA following the formula of IC=VR3/R3
    In the formula above, VR3=IC R3 so when IC=1mA, R3 = 4.7kΩ, VR3= 4.7V.
    When IC=1.25mA, R3 = 4.7kΩ, VR3= 5.87V
    When IC=1.5mA, R3 = 4.7kΩ, VR3= 7.05V
    When IC=1.75mA, R3 = 4.7kΩ, VR3= 8.225V

    Oscilloscope

    When IC=1.25mA, R3 = 4.7kΩ, VR3= 5.87V

    When IC=1.25mA, R3 = 4.7kΩ, VR3= 5.87V

    Oscilloscope

    When IC=1.5mA, R3 = 4.7kΩ, VR3= 7.05V

    When IC=1.5mA, R3 = 4.7kΩ, VR3= 7.05V

    Oscilloscope

    When IC=1.5mA, R3 = 4.7kΩ, VR3= 8.225V

    When IC=1.5mA, R3 = 4.7kΩ, VR3= 8.225V
4.Calculation

1. Calculate DC amplification degree(βdc) and AC amplification degree(βdc) and record in the relevant column of table 7-1.

β_dc=〖∆I〗_C/〖∆I〗_B ,β_ac=V_out/V_in

2. Calculate the saturation current and cutoff voltage and record the load line and operating point(Q).

Saturation Current
I_(C(max))=V_CC/(R_C+R_E )

Cutoff Voltage
V_(CE(Cutoff))=V_CC

Using the graph, calculate the current of operating point(Q) and voltage between collector-emitter.

Fig. 7-3 Circuit (b)

1.Connection(Circuit-1 of M-07)
1.Circuit Connection

Connect between 1g terminal and 1i terminal, between 1f terminal and 1o terminal with yellow lines.

2.Power Connection

It is connected internally

3.Measuring Instrument Connection

Voltmeter Connection for DC Amplification Degree

Measuring the voltage(VR3) of R3’s both ends by using the voltage measurement function of separate Digital Multimeter: Connect the red line of Digital Multimeter to 1d terminal of Circuit-1 and the black line to 1e terminal.

Measuring the voltage(VR4) of R4’s both ends: Connect between 1h terminal of Circuit-1 and High terminal on the front panel of Multimeter with red line, and between 1i(1j,1n) terminal and Low terminal with black line.

Voltmeter Connection for AC Amplification Degree

Measuring input voltage: Connect between 1a terminal of Circuit-1 and A+ terminal of Signal Input CH A on the front panel of Multimeter with red line, and between 1b terminal and A- terminal with black line.

Measuring output voltage: Connect between 1k terminal of Circuit-1 and B+ terminal of Signal Input CH B on the front panel of Multimeter with red line, and between 1l terminal and B- terminal with black line.

2.Wiring Diagram

1) Wiring Diagram for DC Amplification Degree Measurement

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2) Wiring Diagram for AC Amplification Degree Measurement

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3.Measurement
  1. 1DC Amplification Degree Measurement

    Compose as in 2. Wiring Diagram> 1) DC Amplification Degree Measurement.

    Adjust variable resistance R2 and make VR3 as 4.7V, and record the values on the front panel of separate Digital Multimeter in the relevant columns of table 7-2.

    Adjust the value of IC as 1mA following the formula of IC=VR3/R3.
    In the formula above, VR3=IC R3 so when IC=1mA, R3 = 4.7kΩ, VR3= 4.7V.

  2. 2AC Amplification Degree Measurement

    Compose as in 2. Wiring Diagram> 2) AC Amplification Degree Measurement.

    Choose analog output on the left of front panel, click Function Generator and set up Amplitude Range as 2Vpp , Amplitude amplitude 10 , Frequency as 1k, Signal as sine and click on to output 1kHz 2Vpp.

    FunctionGenerator

    Click signal input on the front panel and set up the Oscilloscope screen to show input/output wave form.

    Oscilloscope

    Click quick launch on the left bottom of the screen, choose Analog Output and click arrow right at 10% to increase output voltage. Increase it until the signal wave form of CH B is not distorted, draw the wave form of Oscilloscope, click Volt& Ampere Meter tab and record input voltage of CH A and distortion less output voltage of CH B in the relevant column of table 7-2.

    AnalogOutput Function

    When IC=1.5mA, R3 = 4.7kΩ, VR3= 7.05V

    When IC=1.0mA, R3= 4.7kΩ, and VR3= 4.70V

    VoltAndAmpereMeter

  3. 3Measure the DC and AC amplification degree when IC is 1.1mA, 1.2mA, 1.3mA.

    Execute 1)DC Amplification Degree Measurement, 2) AC Amplification Degree Measurement and record the result in the relevant column of table 7-2.

    Adjust the value of IC as 1mA following the formula of IC=VR3/R3 In the formula above, VR3=IC R3 so when IC=1mA, R3=4.7kΩ, VR3=4.7V.
    When IC=1.1mA, R3 = 4.7kΩ, VR3= 5.17V
    When IC=1.2mA, R3 = 4.7kΩ, VR3= 5.64V
    When IC=1.3mA, R3 = 4.7kΩ, VR3= 6.11V

    When IC=1.1mA, R3 = 4.7kΩ, VR3= 5.17V

    When IC=1.1mA, R3 = 4.7kΩ, VR3= 5.17V

    VoltAndAmpereMeter

4.Calculation

1. Calculate DC amplification degree(βdc) and AC amplification degree(βac) and record in the relevant column of table 7-2.

β_dc=〖∆I〗_C/〖∆I〗_B ,β_ac=V_out/V_in

2. Calculate the saturation current and cutoff voltage and record the load line and operating point(Q).

Saturation Current
I_(C(max))=V_CC/(R_C+R_E )

V_C=V_CC-I_C I_R

Cutoff Voltage
V_(CE(Cutoff))=V_CC

Using the graph, calculate the current of operating point(Q) and voltage between collector-emitter.

Fig. 7-3 Circuit (c)

1.Connection(Circuit-1 of M-07)
1.Circuit Connection

Connect between 1g terminal and 1i terminal, between 1f terminal and 1o terminal, between 1h terminal and 1p terminal, between 1m terminal and 1n terminal with yellow lines.

2.Power Connection

It is connected internally.

3.Measuring Instrument Connection

Connection for DC Amplification Degree

Measuring the voltage(VR3) of R3’s both ends by using the voltage measurement function of separate Digital Multimeter: Connect the red line of Digital Multimeter to 1d terminal of Circuit-1 and the black line to 1e terminal.

Measuring the voltage(VR4) of R4’s both ends: Connect between 1h terminal of Circuit-1 and High terminal on the front panel of Multimeter with red line, and between 1b(1i,1j,1n) terminal and Low terminal with black line.

Voltmeter Connection for AC Amplification Degree

Measuring input voltage: Connect between 1a terminal of Circuit-1 and A+ terminal of Signal Input CH A on the front panel of Multimeter with red line, and between 1b(1i,1j,1n) terminal and A- terminal with black line.

Measuring input voltage: Connect between 1a terminal of Circuit-1 and A+ terminal of Signal Input CH A on the front panel of Multimeter with red line, and between 1b(1i,1j,1n) terminal and A- terminal with black line.

2.Wiring Diagram

1) Wiring Diagram for DC Amplification Degree Measurement

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2) Wiring Diagram for AC Amplification Degree Measurement

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3.Measurement
  1. 1DC Amplification Degree Measurement

    Compose as in 2. Wiring Diagram> 1) DC Amplification Degree Measurement.

    Adjust variable resistance R2 and make VR3 as 4.7V, and record the values on the front panel of separate Digital Multimeter in the relevant columns of table 7-3.

    Adjust the value of IC as 1mA following the formula of IC=VR3/R3.
    In the formula above, VR3=IC R3 so when IC=1mA, R3 = 4.7kΩ, VR3= 4.7V.

  2. 2AC Amplification Degree Measurement

    as in 2. Wiring Diagram> 2) AC Amplification Degree Measurement.

    Choose analog output on the left of front panel, click Function Generator and set up Amplitude Range as 1mV , Amplitude as amplitude 10, Frequency as 10k , Signal as sine and click on to output 1kHz 20mVpp.

    FunctionGenerator

    Click signal input on the front panel and set up the Oscilloscope screen to show input/output wave form.

    Oscilloscope

    Click quick launch on the left bottom of the screen, choose Analog Output and click arrow right at 10% to increase output voltage. Increase it until the signal wave form of CH B is not distorted, draw the wave form of Oscilloscope, click Volt& Ampere Meter tab and record input voltage of CH A and distortion less output voltage of CH B in the relevant column of table 7-2.

    AnalogOutput Function

    When IC=1.0mA, R3 = 4.7kΩ, and VR3= 4.70V

    When IC=1.0mA, R3 = 4.7kΩ, and VR3= 4.70V

    VoltAndAmpereMeter

  3. 3Measure the DC and AC amplification degree when IC is 1.1mA, 1.2mA, 1.3mA.

    Execute 1)DC Amplification Degree Measurement, 2) AC Amplification Degree Measurement and record the result in the relevant column of table 7-2.

    Adjust the value of IC as 1mA following the formula of IC=VR3/R3
    In the formula above, VR3=IC R3 so when IC=1mA, R3=4.7kΩ, VR3=4.7V.
    When IC=1.1mA, R3 = 4.7kΩ, VR3= 5.17V
    When IC=1.2mA, R3 = 4.7kΩ, VR3= 5.64V
    When IC=1.3mA, R3 = 4.7kΩ, VR3= 6.11V

    When IC=1.1mA, R3 = 4.7kΩ, VR3= 5.17V

    When IC=1.1mA, R3 = 4.7kΩ, VR3= 5.17V

    VoltAndAmpereMeter

4.Calculation

1. Calculate DC amplification degree(βdc) and AC amplification degree(βac) and record in the relevant column of table 7-3.

β_dc=〖∆I〗_C/〖∆I〗_B ,β_ac=V_out/V_in

2. Calculate the saturation current and cutoff voltage and record the load line and operating point(Q).

Saturation Current
I_(C(max))=V_CC/(R_C+R_E )

VC=VCC-ICRC

Cutoff Voltage
V_(CE(Cutoff))=V_CC

Using the graph, calculate the current of operating point(Q) and voltage between collector-emitter.

print

Experiment Result Report

result
Amplifier Biasing
1. Experiment Result Table

Table 7-1

result_table
DCIC Setup Value [㎃] 11.251.51.75
IB Setup Value [㎂]
βdc
ACDistortionless Maximum Output [VP-P]
Distortionless Maximum Input [mVP-P]
βac
1) Calculate DC amplification degree(βdc) and AC amplification degree(βac).

β_dc=〖∆I〗_C/〖∆I〗_B ,β_ac=V_out/V_in

2) Draw input/output wave form.

section paper

Table 7-2

result_table
DCIC Setup Value [㎃] 11.11.21.3
R3(4.7kΩ)’s
Both Ends Voltage
R4(2.2kΩ) ‘s
Both Ends Voltage
IE Calculated Value [㎃]
IB Calculated Value [㎂]
βdc
ACDistortionless Maximum Output [VP-P]
Distortionless Maximum Input [VP-P]
βac
1) Calculate DC amplification degree(βdc) and AC amplification degree(βac).

β_dc=〖∆I〗_C/〖∆I〗_B ,β_ac=V_out/V_in

2) Calculate value of IB using Ie=Ve/R4, IB=Ie-IC formula.
3) Draw input/output wave form.

section paper

Table 7-3

result_table
DCIC Setup Value [㎃] 11.11.21.3
R3(4.7kΩ)’s
Both Ends Voltage
R4(2.2kΩ) ‘s
Both Ends Voltage
IE Calculated Value [㎃]
IB Calculated Value [㎂]
βdc
ACDistortionless Maximum Output [VP-P]
Distortionless Maximum Input [VP-P]
βac
1) Calculate value of IB using Ie=Ve/R4, IB=Ie-IC formula

β_dc=〖∆I〗_C/〖∆I〗_B ,β_ac=V_out/V_in

2) Calculate DC amplification degree(βdc) and AC amplification degree(βac).
3) Draw input/output wave form.

section paper

2. Review and Explanation

Circuit 7-2(a)

1) Calculate the saturation current and cutoff voltage and record the load line and operating point(Q).

Saturation Current
I_(C(max))=V_CC/(R_C+R_E )

Cutoff Voltage
VCE(Cutoff)=VCC

Using the graph, calculate the current of operating point(Q) and voltage between collector-emitter.

section paper

Circuit 7-2(b)

Calculate DC amplification degree(βdc) and AC amplification degree(βac).

I_(C(max))=V_CC/(R_C+R_E )

2) Calculate the saturation current and cutoff voltage and record the load line and operating point(Q).

Saturation Current
I_(C(max))=V_CC/(R_C+R_E )

VC=VCC-ICRC

Cutoff Voltage
VCE(Cutoff)=VCC

Using the graph, calculate the current of operating point(Q) and voltage between collector-emitter.

section paper

3. Discuss the experiment result.
1) Compare the characteristics of circuits (a)~(c) in fig. 7-2. Discuss focusing on the factors below.

- (a) circuit : The AC and DC amplification degree is high but it is weak to noise.
- (b) circuit : The AC and DC amplification degree is low but it is strong to noise.
- (c) circuit : The DC amplification degree is low, while AC amplification degree is high, and it is strong to noise.