Class A Amplifier 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 94-101, Electronic Complex, Pardesipura INDORE-452010, India. Tel.: 91-731-2570301 Fax: 91-731-2555643 Email: info@scientech.bz Web: www.scientech.bz
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Class A Amplifier TABLE OF CONTENTS 1.Introduction 4 2. Theory 6 3.Experiment 7 To study the operation of Class A Amplifier. 4.Datasheet 9 5.Warranty 11 6.List of Service Centers 11 7.List of Accessories with 12 3
INTRODUCTION is a compact, ready to use Class A Amplifier experiment board. This is useful for students to understand the working and operation of various Voltage amplifier categories. 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 AB02 AB03 AB04 AB05 AB06 AB07 AB08 AB09 AB10 AB11 AB14 AB15 AB16 AB17 AB18 AB19 AB20 AB22 AB23 AB25 AB28 AB29 AB30 AB31 AB32 AB33 Name Diode characteristics (Si, Zener, LED) Transistor characteristics (CB NPN) 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 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 4
AB41 AB42 AB43 AB44 AB45 AB51 AB52 AB53 AB54 AB56 AB65 AB66 AB67 AB68 AB80 AB81 AB82 AB83 AB84 AB85 AB88 AB89 AB90 AB91 AB92 AB93 AB96 AB97 AB101 AB102 AB106 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 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
THEORY The class A amplifiers are the amplifiers which deliver maximum undistorted symmetrical output voltage swing to the low impedance load. Generally any system (like a stereo, radio or television) consists of several stages of amplification. When the signal passes through these stages, the power level of signal rises so much that the later stages require high power handling circuit elements such as power transistors. Also as the load impedance of these later stages is very small (of the order of 8 ohm for stereo amplifier speakers), heavy collector current flows. To handle this, transistors heaving power rating of 1W or more are used in power amplifiers. Power amplifiers are broadly classified as : 1. Class A (Voltage Amplifier) 2. Class B (Push-Pull Emitter Follower) 3. Class C Tuned Amplifier Class A Amplifier : Class A amplifier is basically a voltage amplifier in which transistor operates in active region for the entire cycle of input AC signal. In other words the collector current flows for 360 of AC signal Fig. 1 For class A amplifiers the Q point is located somewhere near the middle of the AC load line and thus offers maximum amplification of the input signal as shown below : 6
Fig. 2 The collector current IC is non-zero even when the input signal is zero i.e. the IC flows for 100% of time. This leads to power dissipation even in quiescent condition. EXPERIMENT Objective : To study the operation of Class A Amplifier. Apparatus required : 1. Analog board of. 2. Variable DC power supply +12V from external source or ST2612 Analog Lab. 3. Function Generator. 4. Oscilloscope. Circuit diagram : Circuit used to study the operation of Class A Amplifier is shown below : 7
Fig. 3 Procedure : Connect +12V variable DC power supplies at their indicated position from external source or ST2612 Analog Lab. 1. Connect 1Vp-p AC signal (1KHz) at the Vin input of the. 2. Gradually increase the input signal up to the value before the signal just get clipped or decrease the DC supply voltage to the value before the signal just get clipped. This is the maximum amplification of Class A Amplifier. 3. Calculate the peak-to-peak value of the output signal. Connect Oscilloscope at the output terminals of and observe the output waveform. Results Input ac signal amplitude (Vin) :...Vp-p Output ac signal amplitude (Vout) :...Vp-p 8
Voltage gain (A = Vout/Vin) :... 9
DATASHEET 10
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) Before dispatching the instrument please write to us giving full details of the fault noticed. 2) 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. 11
LIST OF SERVICE CENTERS 1. 90, Electronic Complex Pardesipura, INDORE 452010 2. First Floor, C-19, F.I.E., Patparganj Industrial Area, DELHI 110092 3. New no.2, Old no.10, 4th street Venkateswara nagar, Adyar CHENNAI 600025 4. 202/19, 4th main street Ganganagar, BANGALORE- 560032 5. 8,1st floor, 123-Hariram Mansion, Dada Saheb Phalke road, Dadar (East), MUMBAI 400014 6. 988, Sadashiv Peth, Gyan Prabodhini Lane, PUNE 411030 7. Scientech Technologies Pvt. Ltd SPS Apartment, 1st Floor 2, Ahmed Mamoji Street, Behind Jaiswal Hospital, Liluah, HOWRAH-711204 W.B. 8. Scientech Technologies Pvt. Ltd Flat No. 205, 2nd Floor, Lakshminarayana Apartments C wing, Street No. 17, Himaytnagar, HYDERABAD- 500029 Ph : (0731) 2570301 Email : info@scientech.bz Ph : (011) 22157370, 22157371 Fax : (011) 22157369 Email : ndel@scientech.bz Ph : (044) 42187548, 42187549 Fax : (044) 42187549 Email : chennai@scientech.bz Ph : (080) 51285011 Fax : (080) 51285022 Email : bangalore@scientech.bz Ph : (022) 56299457 Fax : (022) 24168767 Email : stplmum@scientech.bz Ph : (020) 24461673 Fax : (020) 24482403 Email : pune@scientech.bz Ph : +913355266800 Email : kolkata@scientech.bz Ph : (040) 55465643 Email : hyd@scientech.bz 12
LIST OF ACCESSORIES 1. 2mm Patch cord (red)...2 Nos. 2. 2mm Patch cord (black)...2 Nos. 3. 2mm Patch cord (blue)...5 Nos. 13