AB66 Wien Bridge Oscillator Analog Lab Experiment Board ... · PDF fileAB66 Wien Bridge Oscillator Analog Lab Experiment Board ... used with SCIENTECH Analog Lab ST2612 which has built

AB66 Wien Bridge Oscillator

Analog LabExperiment 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: 91-731-2555643Email: [email protected] Web: www.scientech.bz

http://www.scientech.bz/

mailto:[email protected]

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Scientech Technologies Pvt. Ltd. 2

AB66

Wien Bridge OscillatorAB66

TABLE OF CONTENTS

1.Introduction 4

2. Theory 6

3.Experiment To study Wien Bridge oscillator and effect onOutput frequency with variation in RC combination. 7

4.Datasheet 9

5.Warranty 10

6.List of Service Centers 11

7.List of Accessories with AB66 12


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INTRODUCTIONAB66 is a compact, ready to use Wien Bridge Oscillator experiment board. This is useful for students to understand functionality of Wien Bridge oscillator and the effect of RC combination on the Output frequency. 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 Name

AB01 Diode characteristics (Si, Zener, LED)AB02 Transistor characteristics (CB NPN)AB03 Transistor characteristics (CB PNP)AB04 Transistor characteristics (CE NPN)AB05 Transistor characteristics (CE PNP)AB06 Transistor characteristics (CC NPN)AB07 Transistor characteristics (CC PNP)AB08 FET characteristicsAB09 Rectifier CircuitsAB10 Wheatstone BridgeAB11 Maxwell’s BridgeAB14 Darlington PairAB15 Common Emitter AmplifierAB16 Common Collector AmplifierAB17 Common Base AmplifierAB18 Cascode AmplifierAB19 RC-Coupled AmplifierAB20 Direct Coupled AmplifierAB21 Class a AmplifierAB22 Class B Amplifier (push pull emitter follower)AB23 Class C Tuned AmplifierAB25 Phase Locked Loop (FM Demodulator & Frequency

Divider / Multiplier)AB28 Multivibrator ( Mono stable / Astable)AB29 F-V and V-F ConverterAB30 V-I and I-V ConverterAB31 Zener Voltage Regulator AB32 Transistor Series Voltage RegulatorAB33 Transistor Shunt Voltage Regulator


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AB41 Differential Amplifier (Transistorized)AB42 Operational Amplifier (Inverting / Non-inverting /

Differentiator)AB43 Operational Amplifier (Adder/Scalar)AB44 Operational Amplifier (Integrator/ Differentiator)AB45 Schmitt Trigger and ComparatorAB51 Active filters (Low Pass and High Pass)AB52 Active Band Pass Filter AB53 Notch Filter AB54 Tschebyscheff FilterAB56 Fiber Optic Analog LinkAB65 Phase Shift OscillatorAB67 Colpitt OscillatorAB68 Hartley OscillatorAB80 RLC Series and RLC Parallel Resonance AB81 Kirchoff’s Laws (Kirchhoff’s Current Law & Kirchhoff’s

Voltage Law)AB82 Thevenin’s and Maximum power Transfer TheoremAB83 Reciprocity and Superposition TheoremAB84 Tellegen’s TheoremAB85 Norton’s theoremAB88 Diode ClipperAB89 Diode ClampersAB90 Two port network parameterAB91 Optical Transducer (Photovoltaic cell)AB92 Optical Transducer (Photoconductive cell/LDR)AB93 Optical Transducer (PhotoTransistor)AB96 Temperature Transducer (RTD & IC335)AB97 Temperature Transducer (Thermocouple)AB101 DSB Modulator and DemodulatorAB102 SSB Modulator and DemodulatorAB106 FM Modulator and Demodulator

………… and many more


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THEORY

Oscillators are circuits that produce periodic waveforms without input other than perhaps a trigger. They generally use some form of active device, lamp, or crystal, surrounded by passive devices such as resistors, capacitors, and inductors, to generate the output.

There are two main classes of oscillator: relaxation and sinusoidal. Relaxation oscillators generate the triangular, sawtooth and other non sinusoidal waveforms. Sinusoidal oscillators consist of amplifiers with external components used to generate oscillation, or crystals that internally generate the oscillation. The focus here is on sine wave oscillators, created using operational amplifiers op amps. Sine wave oscillators are used as references or test waveforms by many circuits.

An oscillator is a type of feedback amplifier in which part of the output is fed back to the input via a feedback circuit. If the signal fed back is of proper magnitude and phase, the circuit produces alternating currents or voltages. Two requirements for oscillation are :

1. The magnitude of the loop gain AVB must be at least 1.

2. The total phase shift of the loop gain AvB must be equal to 0° or 360°. If the amplifier causes a phase shift of 180°, the feedback circuit must provide an additional phase shift of 180° so that the total phase shift around the loop is 360°.

Wien Bridge Oscillator :

The Wien Bridge is one of the simplest and best known oscillators and is used extensively in circuits for audio applications. Figure 1 shows the basic Wien Bridge circuit configuration. On the positive side, this circuit has only a few components and good frequency stability.

Because of its simplicity and stability, it is the most commonly used audio-frequency oscillator. In the Fig shown the Wien Bridge circuit is connected between the amplifier input terminals and the output terminal. The bridge has a series RC network in one arm and a parallel RC network in the adjoining arm. In the remaining two arms of the bridge, resistor R1 and Rf are connected.The phase angle criterion for oscillation is that the total phase shift around the circuit mudt be 0°. This condition occurs only when the bridge is balanced, that is at resonance. The frequency of oscillation Fo is exactly the resonant frequency of the balanced Wien Bridge and is given by


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Fo = 1/2 π RC = 0.159 / RC

Assuming that the resistors are equal in the value, and the capacitors are equal in the value in the reactive leg of the Wien Bridge. At this frequency the gain required for sustained oscillation is given by

Av = 1/B = 3

That is, 1+ Rf / R1 = 3

Or Rf = 2R1

Wien-Bridge Circuit Schematic

Fig. 1EXPERIMENT

Objective :

To study Wien Bridge Oscillator and effect on output frequency with variation in RC combination.

Apparatus required :

1. Analog board of AB66.

2. DC power supplies -12V, +12V from external source or ST2612 Analog Lab.

3. 2 mm patch cords.


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Circuit diagram : Circuit used to study Wien Bridge Oscillator is shown in Fig 2.

Fig. 2Procedure :• To study Wien Bridge oscillator proceed as follows :1. Connect +12V,-12V dc power supplies at their indicated position

from external source or ST2612 Analog Lab.2. Connect a 2mm patch cord between test point I and H.3. Switch ON the power supply.4. Vary Rf Pot to make gain (Rf / Rl) greater than 2.5. Record the value of output frequency at test point G.6. Compare measured frequency with the theoretically calculated value.7. Vary gain Pot of 470K to adjust gain of the amplifier in case of

clipped waveform.8. Switch OFF the power supply.9. Connect a 2 mm patch cord between test points A and B, D and E. 10. Repeat the above steps from step 3 to 8.11. Switch OFF the power supply


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12. Connect a 2 mm patch cord between test points B and C, E and F. 13. Repeat the above steps from step 3 to 8.


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DATASHEET


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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 fully 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.


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LIST OF SERVICE CENTERS

1. Scientech Technologies Pvt. Ltd.90, Electronic Complex Ph : (0731) 2570301Pardesipura, Email : [email protected] INDORE – 452010

2. Scientech Technologies Pvt. Ltd.First Floor, C-19, Ph : (011) 22157370, 22157371F.I.E., Patparganj Industrial Area, Fax : (011) 22157369DELHI – 110092 Email : [email protected]

3. Scientech Technologies Pvt. Ltd.New no.2, Old no.10, 4th street Ph : (044) 42187548, 42187549

Venkateswara nagar, Adyar Fax : (044) 42187549CHENNAI – 600025 Email : [email protected]

4. Scientech Technologies Pvt. Ltd. 202/19, 4th main street Ph : (080) 51285011 Ganganagar, Fax : (080) 51285022 BANGALORE- 560032 Email : [email protected]. Scientech Technologies Pvt. Ltd.

8,1st floor, 123-Hariram Mansion, Ph : (022) 56299457 Dada Saheb Phalke road, Fax : (022) 24168767 Dadar (East), Email : [email protected] MUMBAI –400014 6. Scientech Technologies Pvt. Ltd. 988, Sadashiv Peth, Ph : (020) 24461673 Gyan Prabodhini Lane, Fax : (020) 24482403 PUNE – 411030 Email : [email protected]. Scientech Technologies Pvt. Ltd SPS Apartment, 1st Floor Ph : +913355266800 2, Ahmed Mamoji Street, Email : [email protected]

Behind Jaiswal Hospital, Liluah, HOWRAH-711204 W.B.8. Scientech Technologies Pvt. Ltd Flat No. 205, 2nd Floor, Ph : (040) 55465643 Lakshminarayana Apartments Email : [email protected] ‘C’ wing, Street No. 17, Himaytnagar, HYDERABAD- 500029


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LIST OF ACCESSORIES

1. 2mm Patch cord (red) .........................................................2 Nos.

2. 2mm Patch cord (black) ......................................................2 Nos.

3. 2mm Patch cord (blue) ........................................................3 Nos.


Documents

AB66 Wien Bridge Oscillator Analog Lab Experiment Board ... · PDF fileAB66 Wien Bridge Oscillator Analog Lab Experiment Board ... used with SCIENTECH Analog Lab ST2612 which has built