Analog Lab Experiment Board Ver. 1.0

Transcription

1 Common Base NPN Transistor Characteristics Analog Lab Experiment Board Ver. 1.0 QUALITY POLICY To be a Global Provider of Innovative and Affordable Electronic Equipments for Technology Training by enhancing Customer Satisfaction based on Research, Modern manufacturing techniques and continuous improvement in Quality of the products and Services with active participation of employees. An ISO 9001: 2000 company , Electronic Complex, Pardesipura INDORE , India. Tel.: Fax: info@scientech.bz Web:

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3 Common Base NPN Transistor Characteristics TABLE OF CONTENTS Table of Contents Introduction...4 THEORY...6 EXPERIMENT...9 DATASHEET...16 WARRANTY...18 LIST OF SERVICE CENTERS...19 List of Accessories

4 Introduction is a compact, ready to use Transistor Characteristics experiment board. This is useful for students to plot different characteristics of NPN transistor in common base configuration and to understand various region of operation of PNP transistor. It can be used as stand alone unit with external DC power supply or can be used with SCIENTECH Analog Lab ST2612 which has built in DC power supply, AC power supply, function generator, modulation generator, continuity tester, toggle switches, and potentiometer. List of Boards : Model AB01 AB03 AB04 AB05 AB06 AB07 AB08 AB09 AB10 AB11 AB14 AB15 AB16 AB17 AB18 AB19 AB20 AB21 AB22 AB23 AB25 AB28 AB29 AB30 AB31 AB32 AB33 AB41 AB42 AB43 AB44 AB45 AB51 AB52 AB53 AB54 AB56 AB65 AB66 AB67 AB68 AB80 AB81 AB82 AB83 AB84 AB85 AB88 AB89 Name Diode characteristics (Si, Zener, LED) Transistor characteristics (CB PNP) Transistor characteristics (CE NPN) Transistor characteristics (CE PNP) Transistor characteristics (CC NPN) Transistor characteristics (CC PNP) FET characteristics Rectifier Circuits Wheatstone Bridge Maxwell s Bridge Darlington Pair Common Emitter Amplifier Common Collector Amplifier Common Base Amplifier Cascode Amplifier RC-Coupled Amplifier Direct Coupled Amplifier Class a Amplifier Class B Amplifier (push pull emitter follower) Class C Tuned Amplifier Phase Locked Loop (FM Demodulator & Frequency Divider / Multiplier) Multivibrator ( Mono stable / Astable) F-V and V-F Converter V-I and I-V Converter Zener Voltage Regulator Transistor Series Voltage Regulator Transistor Shunt Voltage Regulator Differential Amplifier (Transistorized) Operational Amplifier (Inverting / Non-inverting / Differentiator) Operational Amplifier (Adder/Scalar) Operational Amplifier (Integrator/ Differentiator) Schmitt Trigger and Comparator Active filters (Low Pass and High Pass) Active Band Pass Filter Notch Filter Tschebyscheff Filter Fiber Optic Analog Link Phase Shift Oscillator Wien Bridge Oscillators Colpitt Oscillator Hartley Oscillator RLC Series and RLC Parallel Resonance Kirchoff s Laws (Kirchhoff s Current Law & Kirchhoff s Voltage Law) Thevenin s and Maximum power Transfer Theorem Reciprocity and Superposition Theorem Tellegen s Theorem Norton s theorem Diode Clipper Diode Clampers 4

5 AB90 AB91 AB92 AB93 AB96 AB97 AB101 AB102 AB106 Two port network parameter Optical Transducer (Photovoltaic cell) Optical Transducer (Photoconductive cell/ldr) Optical Transducer (PhotoTransistor) Temperature Transducer (RTD & IC335) Temperature Transducer (Thermocouple) DSB Modulator and Demodulator SSB Modulator and Demodulator FM Modulator and Demodulator and many more 5

6 THEORY Transistor characteristics are the curves, which represent relationship between different dc currents and voltages of a transistor. These are helpful in studying the operation of a transistor when connected in a circuit. The three important characteristics of a transistor are: 1. Input characteristic. 2. Output characteristic. 3. Constant current transfer characteristic. Input Characteristic : In common base configuration, it is the curve plotted between the input current (IE) verses input voltage (VBE) for various constant values of output voltage (VCB). The approximated plot for input characteristic is shown in Fig. 1. This characteristic reveal that for fixed value of output voltage VCB, as the base to emitter voltage increases, the emitter current increases in a manner that closely resembles the diode characteristics. Fig. 1 6

7 Output Characteristic : This is the curve plotted between the output current IC verses output voltage VCB for various constant values of input current IE. The output characteristic has three basic region of interest as indicated in fig.2 the active region, cutoff region and saturation region. In active region the collector base junction is reverse biased while the base emitter junction if forward biased. This region is normally employed for linear (undistorted) amplifier. In cutoff region the collector base junction and base emitter junction of the transistor both are reverse biased. In this region transistor acts as an OFF switch. In saturation region the collector base junction and base emitter junction of the transistor both are forward biased. In this region transistor acts as an ON switch. Fig. 2 7

8 Constant current transfer Characteristic : This is the curve plotted between output collector current IC verses input emitter current IE for constant value of output voltage VCB. The approximated plot for this characteristic is shown in Fig 3. Fig. 3 8

9 EXPERIMENT Objective : To study the characteristics of NPN transistor in common base configuration and to evaluate 1. Input resistance 2. Output resistance 3. Current gain Apparatus required : 1. Analog board of. 2. DC power supplies +12V, -5V from external source or ST2612 Analog Lab. 3. Digital Multimeter (3 numbers) mm patch cords. Circuit diagram : Circuit used to plot different characteristics of transistor is shown in Fig 4. Fig. 4 9

10 Procedure : Connect -5V and +12V dc power supplies at their indicated position from external source or ST2612 Analog Lab. To plot input characteristics proceed as follows : 1. Rotate both the potentiometer P1 and P2 fully in CCW (counter clockwise direction). 2. Connect Ammeter between test point 2 and 3 to measure input emitter current IE(mA). 3. Short or connect a 2mm patch cord between test point 4 and 5 4. Connect one voltmeter between test point 1 and ground to measure input voltage VBE other voltmeter between test point 6 and ground to measure output voltage VCB. 5. Switch ON the power supply. 6. Vary potentiometer P2 and set a value of output voltage VCB at some constant value (1V, 2V ) 7. Vary the potentiometer P1 so as to increase the value of input voltage VBE from zero to 0.9V in step and measure the corresponding values of input current IE for different constant value of output voltage VCB in an observation Table Rotate potentiometer P1 fully in CCW direction. 9. Repeat the procedure from step 6 for different sets of output voltage VCB. 10. Plot a curve between input voltage VBE and input current IE as shown in Fig 1 using suitable scale with the help of observation Table l. This curve is the required input characteristic. 10

11 Observation Table 1 : S.no. Input Input current IE(mA) at constant value of voltage output voltage VBE V V V V V V V V V V VCB = 1V To plot output characteristics proceed as follows: 1. Switch OFF the power supply. VCB = 3V VCB =5V 2. Rotate both the potentiometer P1 and P2 fully in CCW (counterclockwise direction). 3. Connect voltmeter between test point 6 and ground to measure output voltage VCB. 4. Connect one Ammeter between test point 2 and 3 to measure input current I E(mA) and other Ammeter between test point 4 and 5 to measure output current IC(mA). 5. Switch ON the power supply. 6. Vary potentiometer P1 and set a value of input current IE at some constant value (0mA, 1mA...) 7. Vary the potentiometer P2 so as to increase the value of output voltage VCB from zero to maximum value in step and measure the corresponding values of output current IC for different constant value of input current IE in an observation Table Rotate potentiometer P2 fully in CCW direction. 9. Repeat the procedure from step 6 for different sets of input current IE. 10. Plot a curve between output voltage VCB and output current IC as shown in Fig 2 using suitable scale with the help of observation Table 2. This curve is the required output characteristic. Observation Table 2 : 11

12 Input S.no. Input current IC (ma) at constant value of input voltage voltage VCB V V V V V V V V V V IE = 0mA IE = 1mA IE = 2mA IE = 3mA IE = 4mA To plot constant current transfer characteristics proceed as follows: 1. Switch OFF the power supply. 2. Rotate both the potentiometer P1 and P2 fully in CCW (counter clockwise direction). 3. Connect voltmeter between test point 6 and ground to measure output voltage VCB. 4. Connect one Ammeter between test point 2 and 3 to measure input current IE (ma) and other Ammeter between test point 4 and 5 to measure output current IC (ma). 5. Switch ON the power supply. 6. Vary potentiometer P2 and set a value of output voltage VCB at maximum value. 7. Vary the potentiometer P1 so as to increase the value of input current I E from zero to 10 ma in step and measure the corresponding values of output current IC in an observation Table Plot a curve between output current IC and input current IE as shown in Fig 3 using suitable scale with the help of observation Table 3. This curve is the required Transfer characteristic. Observation Table 3 : 12

13 S.no. Input current IE (ma) ma ma ma ma ma ma ma ma ma ma Output current IC (ma) at constant output voltage VCB = 10 V 13

14 Calculations : 1. Input resistance: It is the ratio of change in the input voltage VBE to change in the input current IE at constant value of output voltage VCB or it is the reciprocal of the slope obtained from the input characteristic. Mathematically To calculate input resistance determine the slope from the input characteristic curve obtained from observation Table 1. Reciprocal of this slope will give the required input resistance. 2. Output resistance: It is the ratio of change in the output voltage VCB to change in the output current IC at constant value of input current IE or it is the reciprocal of the slope obtained from the output characteristic. Mathematically To calculate output resistance determine the slope from the output characteristic curve obtained from observation Table 2. Reciprocal of this slope will give the required output resistance. 3. Current gain: It is the ratio of change in the output current IC to change in the input current IE at constant value of output voltage VCB or it is the slope obtained from the constant current transfer characteristic. It is denoted by αac 14

15 Mathematically αac = Slope of constant current transfer characteristic = IC IE To calculate current gain, determine the slope from the constant current transfer characteristic curve obtained from observation Table 3. This slope is the required current gain. Results: Input resistance Rin = Output resistance Rout = Current Gain αac = 15

16 DATASHEET 16

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18 WARRANTY 1) We guarantee the instrument against all manufacturing defects during 24 months from the date of sale by us or through our dealers. 2) The guarantee covers manufacturing defects in respect of indigenous components and material limited to the warranty extended to us by the original manufacturer, and defect will be rectified as far as lies within our control. 3) The guarantee will become INVALID. a) If the instrument is not operated as per instruction given in the instruction manual. b) If the agreed payment terms and other conditions of sale are not followed. c) If the customer resells the instrument to another party. d) Provided no attempt have been made to service and modify the instrument. 4) The non-working of the instrument is to be communicated to us immediately giving full details of the complaints and defects noticed specifically mentioning the type and sr. no. of the instrument, date of purchase etc. 5) The repair work will be carried out, provided the instrument is dispatched securely packed and insured with the railways. To and fro charges will be to the account of the customer. DESPATCH PROCEDURE FOR SERVICE Should it become necessary to send back the instrument to factory please observe the following procedure: 1) 2) Before dispatching the instrument please write to us giving fully details of the fault noticed. After receipt of your letter our repairs dept. will advise you whether it is necessary to send the instrument back to us for repairs or the adjustment is possible in your premises. Dispatch the instrument (only on the receipt of our advice) securely packed in original packing duly insured and freight paid along with accessories and a copy of the details noticed to us at our factory address. 18

19 LIST OF SERVICE CENTERS 1. 90, Electronic Complex Pardesipura, INDORE First Floor, C-19, F.I.E., Patparganj Industrial Area, DELHI New no.2, Old no.10, 4th street Venkateswara nagar, Adyar CHENNAI /19, 4th main street Ganganagar, BANGALORE ,1st floor, 123-Hariram Mansion, Dada Saheb Phalke road, Dadar (East), MUMBAI , Sadashiv Peth, Gyan Prabodhini Lane, PUNE Scientech Technologies Pvt. Ltd SPS Apartment, 1st Floor 2, Ahmed Mamoji Street, Behind Jaiswal Hospital, Liluah, HOWRAH W.B. 8. Scientech Technologies Pvt. Ltd Flat No. 205, 2nd Floor, Lakshminarayana Apartments C wing, Street No. 17, Himaytnagar, HYDERABAD Ph : (0731) info@scientech.bz Ph : (011) , Fax : (011) ndel@scientech.bz Ph : (044) , Fax : (044) chennai@scientech.bz Ph : (080) Fax : (080) bangalore@scientech.bz Ph : (022) Fax : (022) stplmum@scientech.bz Ph : (020) Fax : (020) pune@scientech.bz Ph : kolkata@scientech.bz Ph : (040) hyd@scientech.bz 19

20 List of Accessories 1. 2mm Patch cord (red)...2 Nos. 2. 2mm Patch cord (black)...2 Nos. 3. 2mm Patch cord (blue)...1 Nos. 20