Other Products / Services #919399

We offer Linear Variable Differential Transformer useful for control labs. The present experimental unit comprises of a LVDT in a transparent box with lead screw based slow motion displacement, a mm scale for displacement measurement, and main unit consisting of excitation signal source, balanced demodulator, a 3 digit DVM and necessary power supplies. The signals are provided to the LVDT box through a cable from the main unit. >>Highlights Large size LVDT for classroom experimentTransparent casing for proper viewingAC and DC outputSlow motion displacement >>Experiments Variation of modulated output with displacementInput-Output characteristicsDetermination of linear range and transducer gain >>Features and Specifications LVDTRange: 50mm or total 100mmSensitivity: 25mV/cmOperating frequency: 5KHz5% Displacement measurement on a mm scale with fine motion controlCarrier source (internal): 5KHz5%; 1.5V (nominal)Built-in 3 digit DVM for output readingIC based balanced demodulator circuitIC controlled internal power suppliesEssential accessory a CRO The experiment is complete in all respect, except a CRO.

High Voltage Power Supply, EHT-11:We offer precision High Voltage Power Supply very useful for general laboratory and R&D labs. EHT-11 is designed to meet the power requirements of a broad range of radiation detectors: G.M. Counters, ionization Chambers, Scintillation Detectors, Photo-multiplier Tubes and any application where a high voltage source with high degree of regulation and stability is required.Specifications Output: 0-1500V continuously adjustableCurrent: 1mA (max.)Polarity: +ve or -ve, as requiredRegulation: 0.05% for 0 to 1mA loadStabilization: 0.02% for 10% mains variationDisplay: 3 digit, 7 segment LED DPMConnection: Output through a amphenol connector on the front panelProtection: Fully protected against overload and short circuit by current limiting techniquePower requirements: 220V 10%, 50HzWeight: 5KgDimensions: 240mm X 390mm X 130mm.

We offer Study of Second Order Networks useful for control labs. Second order networks are important because of the fact that these are the simplest networks that produce the complete range of transient response from over damping to near oscillations. Although theoretical discussions are normally confined to passive RLC networks, such networks are limited in their performance due to the rather large resistance of any reasonable value inductance that might be constructed to operate at frequencies of few kHz. In the present unit active RC-network has been designed which span the complete behavior of an equivalent passive RLC network. The user thus has the experience of studying a near ideal passive second order network complete with all theoretical computations and their experimental verifications. >>Highlights Active second order networkDamping controlover-, critical-, and under-dampingBuilt-in sine wave signalNeeds an external CRO for response studyOperates with 220V/50 HzDetailed technical literature and experiment results supplied >>Experiments Observe and trace from the CRO screen the step response for different values of .Compute approximate values of equivalent network parameters.Plot the frequency response for various of and observe resonance >>Features and Specifications Active RLC network using 3-Op AmpsDamping 1.1-0.1 (approx)Square Wave 35-700 Hz., 0-1V (typical)Sine Wave 35-700 Hz., 0-1V (typical)Essential accessory: a CRO The experiment is complete in all respect, except a CRO.

We Offer D.c. Motor Study Usefull in Control Laboratory Experiment. a D.c. Motor is Commonly Used as An Actuator in Many Industrial Control Applications Because of Its Features Large Torque and Ease of Speed Variation. the Dynamic Characteristics of such a System Therefore Depends On the Motor Parameters, Viz., Moment of Inertia, Coefficient of Friction, Time Constant and also the Resistance and Inductance of the Control Winding. It is Therefore Important to Experimentally Determine the Mechanical and Electrical Parameters of the D.c. Motor and also to Evaluate Its Transfer Function. the Present Unit is Designed to Study a Small Permanent Magnet D.c. Motor. a Still Smaller Generator Directly Coupled to the Motor is Used for the Dual Purposes of Speed Signal Pick Up and Providing Electrical Loading. the Shaft Speed in Rpm is Displayed Automatically On a 4-digit Panel Meter. When the Motor is Suddenly Switched On, a Novel Circuit Computes and Displays the Time Constant in Milliseconds On a 3-digit Panel Meter. this Avoids the Need for An Expensive Storage Cro. the Motor Unit is Housed in a Cabinet with Transparent Panels, Providing a Good View of the Mechanical System. highlights of Equipment: Torque-speed CharacteristicsDetermination of Motor Parameters - Inertia and FrictionDigital Display of Time ConstantTransfer Function Evaluation experiments: Determination of Torque-speed CharacteristicsEvaluation of Inertia and Friction Parameters Determination of Back E.m.f. ConstantDetermination of Time ConstantDetermination of Transfer Functions of the Motor and the Generator features and Specifications Study of a 12v, 8w D.c. MotorSmall Generator (2w) for Speed Pick Up and Loading4-digit Speed Display3-digit Time Constant Display3 Digit Voltmeter and Current Meter for D.c. MeasurementIc Regulated Power SupplySupporting Literature with Experiment Details

We offer Study of Digital-to-Analog Converter, DTA-01 useful for control labs. Measurement of the speed of a rotating shaft is a common requirement in many industrial and laboratory applications. Stroboscope, is a convenient-to-use, direct reading speed measuring instrument. A highly stable function generator IC based circuit provides the basic variable frequency timing pulses.These are read on an IC based LCD/LED counters with direct speed display in rpm. The flasher unit generates the high intensity flashes at a suitably scaled rate directed towards the rotating shaft. Precision potentiometer's makes the task of speed setting very precise. The portable model, fitted into a light weight and strong plastic body is more suited for industrial / class room environment. >> Highlights:- Basic 4-bit weighted resistance4-bit R-2R network module10-bit IC Type AD7533 with mechanical switchesMIcroprocessor interfaced 10-bit converter >> Experiments:- Study of the circuit diagram and performance of a 4-bit weighted resistance type D/A converter. The digital inputs are to be given by operating four mechanical switches.The above experiment is conducted on a 4-bit discrete component R-2R network based unit. Manual operation of a 10-bit IC D/A converter type AD7533 through 10 mechanical switches.Operation of the IC based circuit through the microprocessor kit provided. Some typical waveform generation exercises are suggested and solutions are provided. More problems can be attempted by the student with help from his supervisor. >> Features and Specifications:- Advanced Experiments-arbitrary waveform generationPanel Meter for all measurementsA measuring CRO is needed for viewing the waves forms The experiment is complete in all respect, except a CRO.

We Offer Study of Synchro Devices Useful for Control Labs.highlightssynchro Transmitter-receiver Pair with Calibrated Dialslocking System for Receiver Rotorreceiver Use as Control Transformerbuilt-in Balanced Demodulator Circuitpanel Meter for Ac/dc Voltagesall Internal Power from the 220 V/50 Hz Mains Only An External Cro Required >>introduction Basic Characteristics Study - Stator Voltages as a Function of the Rotor Angle Using the Built-in Ac Voltmeter. this Shows the Space Variation of the Three Voltages, Vs1s2, Vs2s3, and Vs3s1, Causing Rotation of the Resultant Magnetization in the Stator Which is Fundamental to the Error Detection Process.Operation and Error Study of the Transmitter-receiver Pair as a Simple Open Loop Position Control At a Very Low Torque. this is a Rarely Used Application But is Used to Demonstrate the Direction of the Resultant Magnetic Field in the Receiver.Plotting the Error Voltage Output as a Function of the Transmitter Rotor Angle with the Receiver Rotor Locked. Observing the 180 Phase Reversal Around the Zero Error is Significant as this the Basic Method Through Which the Direction of the Error is Detected in An Ac SystemUse of Balanced Demodulator to Develop Dc Error Signal with Appropriate Polarity and Compare It with the Ac Error. this Block Would Be Needed if a Mixed System Were to Be Designed Using Both Dc and Ac Components. the Experiment is Complete in all Respect Except a Cro.

We offer Four Probe Method it is one of the standard and most widely used method for the measurement of resistivity. In its useful form, the four probes are collinear. The error due to contact resistance, which is significant in the electrical measurement on semiconductors, is avoided by the use of two extra contacts (probes) between the current contacts. In this arrangement the contact resistance may all be high compare to the sample resistance, but as long as the resistance of the sample and contact resistance's are small compared with the effective resistance of the voltage measuring device (potentiometer, electrometer or electronic voltmeter), the measured value will remain unaffected. Because of pressure contacts, and 2 way motion, the arrangement is specially useful for quick measurement on large samples at room temperature. Features Easy resistivity mapping of large sample2-way movement with vernier scales (0.01mm)Spring loaded contacts for firm connections Experiment consists of the following: 1. Probes Arrangement, FPA-01It has four individually spring loaded probes. The probes are collinear and equally spaced. The probes are mounted in a teflon bush, which ensure a good electrical insulation between the probes. A teflon spacer near the tips is also provided to keep the probes at equal distance. The probe arrangement is mounted in a tube, which also provide leads for connections to Constant Current Power Supply and D.C. Microvoltmeter. The tube containing four probes is mounted on a travelling microscope type system, scales and verniers are made of stanless steels with following specification: Horizontial: 20 cm least count 0.001 cmLaterial: 6 cm least count 0.001 cmVertical: 15 cm least count 0.001 cm The bed is of heavy casting, thoroughly aged and machined, is fitted with leveling screws. A large platform is provided for fixing the sample. 2. Constant Current Source a) Constant Current Source, Model : CCS-01(for low resistivity samples)The current source is suitable for the resistivity measurement of low to medium resistivity samples such as thin films of metals/ alloys and semiconductors like germanium. SpecificationsOpen Circuit Voltage: 12 VCurrent Range: 0-20mA, 0-200mAResolution: 10AAccuracy: 0.25% of the readingDisplay: 3 digit, 7 segment LEDLoad Regulation: 0.1% for 0 to full loadLine Regulation: 0.1% for 10% changes b) Low Current Source, Model : LCS-02(for high resistivity sample)This current source is especially suitable for the resistivity measurement of polymer ceramics and Si crystals. SpecificationsOpen Circuit Voltage: 15VCurrent Range: 0-2A, 0-20A, 0-200A & 0-2AResolution: inA at 0-2A rangeAccuracy: 0.25% of the reading 1 digitDisplay: 3 digit, 7 segment LCD with autopolarityLoad Regulation: 0.1% for 0 to full loadPower: 3 x 9V batteries 3. D.C. Microvoltmeter, DMV-001 The experiment complete in all respects.

We offer Magnetic Field Measurement Apparatus, this experiment consists of two coils, Constant Current Power Supply and Gaussmeter. The Gaussmeter probe is mounted on a rail with a scale. It can move smoothly and precisely for measurement of magnetic field along the centre of the coils. The following studies can be carried out with the set-up:1. Study of magnetic field due to one coil and calculation of its diameter.2. Study of Principal of super-imposition of magnetic field due to 2 coils by keeping the distance between the coils at a, >a and aLine 2- Magnetic Profile when the distance between coils is =aLine 3- Magnetic Profile when the distance between coils is

We are offering Ionisation Potential Setup useful in Physics and Material Science Lab. The ionisation potential i.e. The energy required to remove an electron completely from the atom. The experiment is consists of the following: Argon filled tetrodeFilament Power SupplyPower Supply for VG1KPower Supply for VKAPower Supply for VG2KSaw tooth waveform for CRO displayMultirange VoltmeterMultirange Ammeter All this is housed in a cabinet with meters and adjustment knobs on the front panel. The set-up can also directly display the anode current variation with VG2K on the oscilloscope screen. It can thus be used as a laboratory experiment as well as for demonstration to a group of students. Analysis of the Data Point by point data for the anode current with VG2K changing in steps of 1V at VG1K equal to 1.5V and VKA equal to 3.0V can be verified experimentally by drawing a graph. The on-set of the anode current and the point where the slope of the current changes can be determined by locating the points of intersection of the lines. These points are at 16V and 31V respectively. The former corresponds to the ionization potential and the latter for the ionization again. The average value of the ionization potential thus found is 15.5 eV compared with the accepted value of 15.6eV.

We offer Study of Magnetic Levitation System useful for control labs. Magnetic Levitation, lifting of objects under the influence of a magnetic field, has numerous application including some advance locomotives designed on the repulsive force of a magnet. The present unit, based on the attractive force of an electromagnet, is inherently unstable. There is no way to keep an iron object suspended in air by manually adjusting the current in the electromagnet. Even a feedback control with forward path gain control alone is ineffective. These facts are brought out by studying and experimenting with the dynamics of the system. The next task consists of the design of suitable controller and implementing the same to achieve the desired objective. A sound knowledge of MATLAB and its availability should be highly desirable, though not essential, for the conduct of this experiment. The basic theory, analysis and sample calculation are described in the accompanying literature. >>Highlights Object suspended in air by magnetic force excellent visual impactController design to maintain stability Up-down position setting by reference control >>Experiments To develop the transfer function of the system through laboratoryTo design/implement PD and lead compensation with different parameterTo simulate the system in MATLAB and study in detail various control option and their response >>Features and Specifications Object suspended in air by magnetic forceController design to maintain stabilityPosition changing by referenceBuilt-in power supplies, meters etc220V/50Hz operation Detailed technical literature included The experiment is complete in all respect.

Our Dielectric Constant Setup is a laboratory experiment to demostrate to the students the concept of Dielectric Constant, its measurement, measurement of curie temperature. Dielectric or electrical insulating materials are understood as materials in which electrostic field can persist for long times. Layers of such substances are commonly inserted into capacitors to improve their perfomance, and the term dielectric refers specifically to this application.An electric field polarizes the molecules of dielectric, producing concentrations of charge on its surface that create an electric field opposed (antiparallel) to that of capacitor. This reduces the electric potential. Considered in reverse, this means that, with a dielectric, a given electric potential causes the capacitor to accumulate a larger charge. All ferroelectric materials have a transition point called the Curie point (Tc). At T>Tc, the crystal does not exhibit ferroelectricity, while for T

We offer A.C. Servomotor Study usefull for control laboratory experiments. Two phase a.c. servomotor is one of the very important electromechanical actuators having applications in the area of control systems. The study of its operating principle and features form a part of the first course on automatic control systems in electrical engineering curriculum. It's small size, low inertia and almost noise and frictionless operation makes the a.c. servomotor particularly attractive in aircraft and spacecraft applications.The characteristics of an a.c. motor is usually non-linear. To simplify the analysis a linearized model is developed. The experimental work revolves around determination of the parameters of the motor and thus its transfer function.Important subsystems of the unit includes, (a) an integrated speed sensor with 4-digit display in r.p.m.(b) an electrical loading system to compute torque(c) a time-constant measurement circuit with 3-digit display in milli seconds(d) a three step a.c. source with built-in r.m.s. voltmeter, and(e) a digital voltmeter on the panel for load measurementThe unit has been designed such that expensive equipment like storage CRO is not needed. Also the hassle of direct torque measurement using spring balance etc. is avoided by linearization of the motor characteristics analytically. Highlights of Equipment Torque computation through electrical loadingDetermination of motor para-meters - inertia and frictionDigital display of time constantTransfer function evaluation Experiments Inertia and friction parametersTime constantTransfer function Features and Specifications 2-phase a.c. servomotor - 12V/ 50Hz per phaseSmall generator for loading4-digit speed display3-digit time constant display3 digit r.m.s. voltmeter 3 digit d.c. panel meterVoltage regulated internal suppliesDetailed literature with sample results The experiment is complete in all respect.

IntroductionWe offer D.C. Speed Control System, DCS-201 usefull for control laboratory. Closed loop speed control of dc motor is a common experiment for studying various features of automatic control systems like control, regulation and disturbance rejection. The present unit is designed to demonstrate the working of PWM and SCR based controllers and show the resulting waveforms of the voltage supplied to the motor. Measurement of the timings on the waveforms under various conditions has been suggested to get a good insight into the operation of the system. The experiment is complete with all the sub-systems and a detailed operating literature is included which introduces the basic theory, suggested experiments and an interpretation of the results. An external CRO is all that is needed to view the waveforms and measure the timings. Highlights PWM Power ControlSCR Power ControlCRO Display of Waveforms4-Digit Speed Display in rpmContactless Eddy Current Braking Experiments Open loop speed control for PWM Controller, with and without loadOpen loop speed control for SCR Controller, with and without loadClosed loop speed control for PWM Controller with loadClosed loop speed control for SCR Controller with loadObservation and measurements on the voltage waveforms Features and Specifications Speed control of a 12V, 4W permanent magnet d.c. motorSpeed range: 0 to 2000 rpm (typical)Opto-interrupter based speed sensing4-digit speed display in rpmElectronic tachogenerator for feedbackSeparate unit for motor in a see-through cabinetSmooth, non-contact eddy current brake 220V10%, 50Hz mains operationSupporting literature and patch cords includedEssential accessory a CRO The experiment is complete in all respect except a CRO.

We offer IC Regulated Power Supply, it is general purpose power supply consists of four independent fixed voltage regulated sources viz. +12 V, -12 V, +5 V and -5 V referred to a common ground. The current rating for each is specified at 300 mA, although it is possible to exceed this limit safely when all four sources are not operating simultaneously.The compact power supply unit is well suited for any general laboratory which uses linear and digital circuits and IC's. At the same time the excellent performance of the 3-terminal regulators enables the supplies to be used equally satisfactorily for sophisticated inst-rumentation applications. The built-in protection of the regulator in the form of over current and safe area shutdown ensure continued fault free operation of the unit without any maintenance. SPECIFICATIONS : Output voltage: + 12 V, - 12 V, + 5 V, - 5 V fixedCurrent: 300 mA (each supply)Line Regulation: 0.05 % for 10 % variation of mains voltage.Load Regulation: 0.1% for a full load of 300 mAProtection: Thermal and overcurrent.Dimensions: 210 m.m. X 180 m.m. X 100 m.m.Weight: 2.25 Kg

We offer D.C. Speed Control System useful for control labs. The present unit, built around a small permanent magnet d.c. motor, is designed to bring out the salient features of such a system. Facilities are available to directly measure the principal performance features of the speed control system, viz., steady state error and load disturbance rejection, as a function of the forward path gain. In addition, the experimental work involves the determination of the motor transfer function and the characteristics of the tachogenerator. Highlights: Closed loop motor speed control with eddy current brakeCompact system-no mechanical hasslesOptoelectronic speed sensorDigital display of speed on the panel Experiments: Effect of loading on the speed of the motor in the open loopSteady state error variation with forward gainSystem time constant variation with forward gainEffect of forward gain on disturbance rejectionDetermination of the motor transfer function and tachometer characteristics Features and Specifications Speed control of a 12V, 4W permanent magnet d.c. motorSpeed range: 0 to 3000 rpm (typical)Opto Interrupter based speed sensing4-digit speed display in rpmElectronic tachogenerator for feedbackSeparate unit for motor in a see-through cabinetSmooth, non-contact eddy current brake for loadingBuilt-in 3 digit DVM for signal measurementsBuilt-in IC regulated internal power supplySupporting literature and patch cords includedEssential accessory a CRO The experiment is complete in all respect, except a CRO.

Offering Study of Planck's Constant, PCA-01.We offer Study of Planck's Constant very useful for Physics and Material Science labs. Several proposals to measure the Plancks Constant for didactic purposes, using the current voltage (I-V) characteristics of a light emitting diode (LED) have been made quite regularly in the last few years. The physical interpretation however is not completely clear and this has raised many discussions, which have been published almost with same regularity as the proposals themselves.The present experiment is based on diode current for V

We offer A.C. Position Control System usefull in control laboratory experiment. 2-phase ac servomotors have been traditionally used for position/ speed control applications especially in light weight, precision instrumentation area in airborne systems. The present unit is designed around a 12V ac servomotor and exposes the basic characteristics and dynamics of a position control system. A block diagram of the system is shown in figure below.Besides introducing the basic features like balanced modulation of the error signal, phase reversal around the set point and phase difference between the reference and control phases of the motor, the experiment involves study of the step response of the closed loop system. Being a mechanical system the response is too slow for a comfortable viewing on a CRO, except on an expensive storage oscilloscope. A microprocessor based waveform capture/ display card in the unit stores the step response in real time and displays the same once steady state is reached. Highlights of Equipment: 2-phase A.C. ServomotorServo Potentiometer for position sensingTransient response capture/displayIn-built rms voltmeter on panel Experiments: Error detector characteristics, phase reversalAmplifier gain measurementPhase difference between control and reference windingsStep response study Features and Specifications 2-phase servomotor 12 volt/phase, 50Hz, 10 wattPower amplifier for drivingServo potentiometer type error detectorIn-built 10.00 volt (rms) panel meterStep response capture/display card Detailed literature with typical results includedComplete unit except a measuring CRO220 volts, 50 Hz mains operation The experiment is complete in all respect

We offer Two Probe Method, it is one of the standard and most commonly used method for the measurement of resistivity of very high resistivity samples like sheets/films of polymers. The resistivity measurement of such samples is beyond the range of Four Probe Method. The experimental Set-up consists of the following: 1. Two Probes Arrangement, TPA-01It has two spring load contact probes. These probes move in a pipe and are insulated by Teflon washers. This probes arrangement is mounted in suitable stand, which also hold the sample plate and RTD sensor. The stand also serves as the lid of PID controlled Oven. Teflon coated leads are provide for connecting with High Voltage Power Supply EHT-11 and Digital Picoammeter DPM-111. With the set-up assuming max. voltage = 1500V; current 100x10-12 A (max) and thickness of sample 1mm. The resistivity of the sample could be measured upto 1014 ohm.cm. 2. PID Controlled Oven, PID-200This is a high quality temperature controlled oven suitable for Four Probe Set-up. The oven has been designed for fast heating and cooling rates, which enhances the effectiveness of the controller. While the basic design of the controller is around the PID configuration for its obvious advantages, wastage of power is avoided by using a Pulse Width Modulated (PMW) switch. This combination has the advantages of both on-off controller and linear PID controller. The result is a good stable and accurate temperature control. Platinum RTD has been used for sensing the temperature. A wheatstone bridge and an instrumentation amplifier are used for signal conditioning. Feedback circuit ensures offset and linearity trimming to a great degree of accuracy. The set and measured temperature are displayed on 3 digit DPM through selector switch. Specifications of the Oven Temperature Range: Ambient to 200CResolution: 0.1CShort Range Stability: 0.2CLong Range Stability: 0.5CMeasurement Accuracy: 0.5C (typical)Oven: Specially designed for Two Probe Set-UpSensor: RTD (A class)Display: 3 digit, 7 segment LEDPower: 150W 3. High Voltgae Power Supply, EHT-11 Output: 0-1500V continuously adjustableCurrent: 1mA (max.)Polarity: +ve or -ve, as requiredRegulation: 0.05% for 0 to 1mA loadStabilization: 0.02% for 10% mains variationDisplay: 3 digit, 7 segment LED DPMConnection: Output through a amphenol connector on the front panelProtection: Fully protected against overload and short circuit by current limiting techniquePower requirements: 220V 10%, 50HzWeight: 5KgDimensions: 240mm X 390mm X 130mm. 4. Digital Picoammeter, DPM-111 Multiplier: X1, X10, X102, X103 , X104 , X105Accuracy: 0.2% for all rangesResolution: 1pA, 10pA, 100pA, 1nA, 10nA, 100nAInput Resistance: 2.5K, 0.25K, 25, 2.5, 0.25, 0.025Display: 3 digit, 7 segment LED (12.5mm height) with auto polarity and decimal indication.Input: Through Amphenol connector.Power Supply: 220V10%, 50Hz.Weight: 2.5Kg.Dimensions: 240mm X 275mm X 120mm. The experimental set-up is complete in all respect.

We offer Study of Integrated Circuit Regulator, the following studies can be carried out:(i) Study of a voltage regulator.(ii) Study of a current regulator.The experimental set-up consists of an IC 723 with facilities for convenient connections, an unregulated power supply, voltmeter, an ammeter and all the other components required to perform the experiments.The set-up is so designed that no high voltage is exposed and hence safe in handling by the students.

We offer Semiconductors Diodes Characteristics with this following characteristics can be studied:Forward and reverse characteristics of Ge, Si diodes and LEDsStudy of Zener diode characteristicsCRO display of forward and reverse characteristics. The set-up is provided with a booklet which contains its theory of operation, description, suggestions and discussion of the experiments that my be performed with it. The circuit is all electronic using transformer and electronic components Viz. ICs, transistors, capacitors and resistance etc. The whole circuit operates on 200V 10% 50 Hz AC and mounted in a metallic cabinet which is grounded through the grounding lead of power connector and hence safe towards electrical hazard, if any.

We offer Magnetoresistance set-up, it is noticed that the resistance of the sample changes when the magnetic field is turned on. The phenomenon, called magnetoresistance, is due to the fact that the drift velocity of all carriers is not same. With the magnetic field on; the Hall voltage V = Eyt = v X H compensates exactly the Lorentz force for carriers with the average velocity; slower carriers will be over compensated and faster one undercompensated, resulting in trajectories that are not along the applied field. This results in an effective decrease of the mean free path and hence an increase in resistivity.Here the above referred symbols are defines as: v = drift velocity; E = applied electric field; t = thickness of the crystal; H = Magnetic field. The set-up consists of the following: (1) Four Probe arrangement, MRA-01It consists of 4 collinear, equally spaced (2mm) and individually spring loaded probes mounted on a PCB strip. Two outer probes for supplying the constant current to the sample and two inner probes for measuring the voltage developed across these probes. This eliminates the error due to contact resistance which is particularly serious in semiconductors. A platform is also provided for placing the sample and mounting the Four Probes on It. (2) SampleGe Crystal (n-type) dimensions: 10 x 10 x 0.5mm. (3) Magnetoresistance Set-up, Model DMR-01This unit consists of a digital millivoltmeter and constant current power supply. The voltage and probe current can be read on the same digital panel meter through a selector switch. (a) Digital MillivoltmeterIntersil 3 digit single chip ICL 7107 have been used. Since the use of internal reference causes the degradation in performance due to internal heating an external reference have been used. Digital voltmeter is much more convenient to use, because the input voltage of either polarity can be measured. SpecificationsRange : 0-200mV (100V minimum)Accuracy : 0.1% of reading 1 digit (b) Constant Current Power SupplyThis power supply, specially designed for Hall Probe, provides 100% protection against crystal burn-out due to excessive current. The supply is a highly regulated and practically ripple free dc source. SpecificationsCurrent : 0-20mA Resolution : 10AAccuracy : 0.2% of the reading 1 digitLoad regulated : 0.03% for 0 to full loadLine regulation : 0.05% for 10% variation (4) Electromagnet, EMU-50V (5) Constant Current Power Supply, DPS-50 (6) Digital Gaussmeter, DGM-102/DGM-202 The Set-up complete in all respect.

We offer Study of a Transistor Amplifier (Rc Coupled) Cum Feed-Back Amplifier with this following studies can be carried out with this set-up Study of the basic circuit of a RC Coupled Amplifier.Frequency response of RC Coupled Amplifier.Effect of negative feedback on the gain and frequency response of the amplifierEffect of positive feedback on the gain and frequency response of the amplifier.Verification of the condition of oscillation.Study of different classed of amplifier. Accessories Required (i) R.F. Oscillator(ii) True RMS A.C. Millivoltmeter, ACM-102 The set-up is so designed that no high voltage is exposed and hence safe in handling by the students.

We offer Characteristics of Semiconductors Diodes, this experiment set-up consists of the following: Diodes: 1N4007, 1N34, 5.1V Zener and LED.3 digit DPM for voltage measurementPrecision resistances for measurement of forward and reverse current.IC regulated power supply. The following studies can be carried out with this set-up: Forward and reverse characteristics of both Ge, Si diodes & LEDs.Study of Zener diode characteristics. The set-up is so designed that no high voltage is exposed and hence safe in handling by the students.

An Experiment Designed for Study Basic Working of 741-ic Measurement of Its Bias and Offset Currents, Study of Inverting & Non-inverting Configuration and Study of Amplifier Drift.

We offer Study of a Solid State Power Supply, following studies can be carried out with this set-up(1) Study of rectification.(a) Full wave rectification(b) Half wave rectification. (2) Study of ac component (Ripples):(a) Efficiency of various type of filters - ???, T type etc(b) The effect of load(c) The effect on regulation (3) Regulation characteristics:(a) The effect of load on regulation.(b) The effect of change in mains voltage. Accessories Required : (i) Multimeter, (ii) Oscilloscope The set-up is so designed that no high voltage is exposed and hence safe in handling by the students.

We offer em Experiment, our arrangement for measuring em, the charge to mass ratio of the electron is a very simple set-up. It is based on Thomsons method. The em-tube is bulb-like and contains a filament, a cathode, a grid, a pair of deflection plates and an anode. The tube is filled with helium at a very low pressure.Some of the electrons emitted by the cathode collide with helium atoms which get excited and radiate visible light. The electron beam thus leaves a visible track in the tube and all manipulations on it can be seen. The tube is placed between a pair of fixed Helmholtz coils which produce a uniform and known magnetic field. The socket of the tube can be rotated so that the electron beam is at right angles to the magnetic field. The beam is deflected in a circular path of radius r depending on the accelerating potential V, the magnetic field B and the charge to mass ratio em. This circular path is visible and the diameter d can be measured and em obtained from the relationem = 8VB2d 2This set-up can also be used to study the electron beam deflection for different directions of the magnetic field by varying the orientation of the em-tube.Description of the Experimental Set-UpThe central part of the set-up is the em-tube. This is energized by(i) Filament current supply(ii) Deflection plates voltage supply(iii) Continuously variable accelerating voltage supply to the anode.SpecificationsHelmholtz coils of radii: 14 cmNumber of turns: 160 on each coilAccelerating Voltage: 0 250VDeflection plates voltage: 50V 250VOperating Voltage: 220V AC 50Hz

An Experiment Designed for Study of Carrier Signal, Variation of Modulated Wave and Detector Circuit.

We offer Study of a Modulation and Demodulation with Built-in Carrier Frequency Source (Solid State), the following studies can be carried out with this set-up: Carrier signal testing.Variation of modulated wave with the modulation signal.Study of detector circuit. The experimental set-up is provided with a built-in power supply.Accessories Required:(i) Function Generator, FG-01(ii) OscilloscopeThe set-up is so designed that no high voltage is exposed and hence safe in handling by the students.

We offer Study of 741 Applications, Features Study of linear and non linear applications as: - Integrator - Differentiator - Summer - Subtractor - Voltage to Current converter - Current to Voltage converter - Astable Mode - Precision rectifier Built-in power supply Built-in square wave and triangular wave Generator Built-in current source. The set-up is so designed that no high voltage is exposed and hence safe in handling by the students.

We offer Study of Multivibrators, this experiment consists of the following: Free Running vibratorUnivibratorBistable MultivibratorsRegulated Power Supply The free running multivibrator also serve as a pulse generator for the study of bistable multivibrator and univibrator. The set-up is so designed that no high voltage is exposed and hence safe in handling by the students.

We offer Study of Astable & Monostable Multivibrator using Timer Ic, TYPE-555, the following studies can be carried out with this setup: Operation as a free running multivibratorOperation as a monostable multivibratorOperations as a preset time delay. The set-up is so designed that no high voltage is exposed and hence safe in handling by the students.

We offer Hall Effect in Metals, it enables the charge carrier concentration and mobility to be determined by experiment. Direction of the Hall Voltage in silver indicates negative charge carriers, which is in agreement with concepts of the model of the free electron gas. Limitations of this model are shown by the so called abnormal Hall Effect of tungsten. The experiment carried out under identical conditions for tungsten show the Hall Voltage to have about same magnitude but opposite direction as in silver.This can be explained by the Energy Band diagram. The tungsten atom has .5s2 5p6 5d4 6s2 electronic structure. When the atoms come close together to form the solid, the close lying states 5d and 6s broaden into bands, with s band broadening considerably more than the d band. This is because of the larger size of the s orbital. The figure schematically shows the allowed energies as a function of the interatomic distance. The number of allowed states is ten per atom in the d band and two in the s band. In tungsten there are six electrons to be shared between these two bands. The result is that at the interatomic distance in tungsten there are holes in the d band and electrons in the s band, making tungstenpredominantly a hole conductor. The apparatus consists of the following: a) Hall Probe-Silver (HP-Ag)Material: Silver Strip (8 x 6 x 0.05 mm)Contacts: Press type for currentSpring Type for VoltageHall Voltage: 17 V/10A/10KG b) Hall Probe-Tungsten (HP-W)Material: Tungten Strip (8 x 6 x 0.05 mm)Contacts: Press type for currentSpring Type for VoltageHall Voltage: 15 V/10A/10KG c) High Current Power Supply, Model PS-20ARange: 0-20A continuosly variableAccuracy: 0.5%Regulation: 0.5% for 10% variation of mainsDisplay: 3 digit, 7 Segment LED d) Digital Microvoltmeter, DMV-001 Range: 1mV, 10mV, 100mV, 1V & 10V with 100% over-ranging.Resolution: 1V.Accuracy: 0.2%.Stability: Within 1 digit.Input Impedance: >1000M (10M on 10V range).Display: 3 digit, 7 segment LED with auto .polarity and decimal indication e) Electromagnet, Model EMU-75TPole Pieces: 75mm tappered to 25mmMag. Field: 17KG 5% at 10mm airgapEnergising Coils: Two of approx. 13W eachPower: 0-90Vdc, 3A, for coils in series0-45Vdc, 6A, for coils in parallelf) Constant Current Power Supply, Model DPS-175 g) Gaussmeter, DGM-202 The experiment is complete in all respect.

We offer Four Probe Method is one of the standard and most widely used method for the measurement of resistivity. In its useful form, the four probes are collinear. The error due to contact resistance, which is significant in the electrical measurement on semiconductors, is avoided by the use of two extra contacts (probes) between the current contacts. In this arrangement the contact resistance may all be high compare to the sample resistance, but as long as the resistance of the sample and contact resistance's are small compared with the effective resistance of the voltage measuring device (potentiometer, electrometer or electronic voltmeter), the measured value will remain unaffected. Because of pressure contacts, the arrangement is also specially useful for quick measurement on different samples or sampling different parts of the sample. The experiment consists of the following: 1. Probes Arrangement, FPA-RM:The probes arrangement is mounted in a suitable stand, which holds the sample plate and RTD (A class) sensor. 2. PID Controlled Oven, PID-200 Temperature Range: Ambient to 200C Resolution: 0.1CShort Range Stability: 0.2C Long Range Stability: 0.5CMeasurement Accuracy: 0.5C (typical)Oven: Specially designed for Four Probe Set-UpDisplay: 3 digit, 7 segment LED with autopolarity 3. Constant Current Source a) Constant Current Source, Model : CCS-01(for low resistivity samples)The current source is suitable for the resistivity measurement of low to medium resistivity samples such as thin films of metals/ alloys and semiconductors like germanium. SpecificationsOpen Circuit Voltage: 12 VCurrent Range: 0-20mA, 0-200mAResolution: 10AAccuracy: 0.25% of the readingDisplay: 3 digit, 7 segment LEDLoad Regulation: 0.1% for 0 to full loadLine Regulation: 0.1% for 10% changes b) Low Current Source, Model : LCS-02(for high resistivity sample)This current source is especially suitable for the resistivity measurement of polymer ceramics and Si cryustals. SpecificationsOpen Circuit Voltage: 15VCurrent Range: 0-2A, 0-20A, 0-200A & 0-2AResolution: inA at 0-2A rangeAccuracy: 0.25% of the reading 1 digitDisplay: 3 digit, 7 segment LCD with autopolarityLoad Regulation: 0.1% for 0 to full loadPower: 3 x 9V batteries 4. D.C. Microvoltmeter, DMV-001 Range: 1mV, 10mV, 100mV, 1V & 10V with 100% over-ranging.Resolution: 1V.Accuracy: 0.2%.Stability: Within 1 digit.Input Impedance: >1000M (10M on 10V range).Display: 3 digit, 7 segment LED with auto .polarity and decimal indication The experiment complete in all respect

We offer Electromagnet, EMU-75 is useful in general laboratory and R&D labs. It has the most widely used 'U' shaped soft iron yoke. The soft iron is of a special quality, structurally uniform, well machined and finished to meet the rigid standards. The pole pieces are made from dead annealed soft iron blocks of the best quality available. They are well shaped, machined and finished. The air-gap is continuously variable up to 75mm with two way knob bed wheel screw adjusting system. Normally flat pole pieces are supplied. Tapered pole pieces can be supplied on special request. The coils are wound on non-magnetic formers with uniform layers of S.E. copper wire. The new and modern design of the coils provides good thermal conductivity characteristics and eliminates troublesome hot spots even at high magnetic fields. Specifications of EMU-75Pole Pieces: 75mm flat in EMU-75: 75mm tapered to 25mm in EMU-75TField: EMU-75: 10.75KG at 10mm air gap: EMU-75T: 17.5KG at 10mm air gapEnergizing Coils: Two, each having a resistance of approx. 13Power Requirement*0-90Vdc, 3A, if coils are connected in series*0-45Vdc, 6A, if coils are connected in seriesConstant Current Power Supply DPS-175 is designed to be used with the Electromagnet, Model: EMU-75 as a constant current power supply to generate magnetic field up to 11KG. Specifications of DPS-175Current: 0-3A per coil Smoothly adjustableLine Regulation: 0.1% for 10% mains variationLoad Regulation: 0.1% for load variation from 0 to max.Display: 3 digit, 7 segment LED displayProtection: Protected against overload, short circuit and transients caused by the load inductance.Power: 220V 10%, 50Hz or 110V 10%, 60Hz as requiredWeight: 13Kg.

Electromagnet & power supply EMU-50 & DPS-50.We are offering Electromagnet & Power Supply. These electromagnets have the most widely used U shaped soft iron yoke. The soft iron is of a special quality, structurally uniform, well machined and finished to meet the rigid standards.The air-gap is continuously variable with two way knobbed wheel screw adjusting system. EMU-50V is supplied with flat pole pieces and EMU-50T is supplied with tappered pole pieces. SpecificationsPole Pieces: 50mm diameter flat in EMU-50: 50mm tapered to 20 mm in EMU-50TField: EMU-50: 7.5KG, at 10mm airgap: EMU-50T: 9.5KG at 10mm airgapEnergizing Coils: Two, each with a resistance of about 3WPower Requirement: 0-30Vdc, 4A, if coils are connected in seriesDPS-50 is an inexpensive and high performance constant current source suitable for small and medium sized electromagnets. Although the equipment is designed for the Electromagnet, Model: EMU-50, it can be used satisfactorily with any other electromagnet provided the coil resistance does not exceed 6. SpecificationsCurrent Range: Smoothly adjustable from 04ALoad Regulation: 0.1% for load variation from 0 to max.Line Regulation: 0.1% for 10% mains variationDisplay: 3 digit, 7 segment LED DPMPower: 220V 10%, 50HzWeight: 9KgDimensions: 335mm X 305mm X 155mm

We offer Study of a power supply (Solid State) physics ans electronics experimental setup. The Set-up consists of a step-down transformer, a rectifier circuit (can be used as a half-wave or a full-wave rectifier), a filter circuit (an inductance and two capacitors) - the arrangement can be used for the study of various configuration of filters and a regulator circuit. A built-in electronic load is used to smoothly vary the load current while a digital panel meter on the board measures the load current and load voltage. FEATURES 1. Study of rectification: (a) Full wave rectification(b) Half wave rectification(c) Bridge rectification 2. Study of ac component: (a) Efficiency of various (Ripples) type of filters L, , T type etc.(b) The effect of load(c) The effect of regulation 3. Regulation characteristics: (a) The effect of load on regulation(b) The effect of change in mains voltage 4. Electronic Load: To draw the load current smoothly SPECIFICATIONS Output: 0-12 voltsMax. Current: 200 mARegulation: 1%Metering: Output Voltahe/ Current on the switchable DPM The experimental set-up is complete in all respect, except a Multimeter and a CRO

We offer Study of P-N Junction, this is an advanced level experiment to be performed on commercially available diodes viz. germanium or silicon diodes, various types of LEDs and also on the base-emitter/collector-base junctions of a transistor. The results of the experiments not only give the device characteristics but also provide an insight into the properties of the materials used in the fabrication of the junction. In the set-up, all the necessary instrumentation is integrated as a result of which a minimum of external connections need to be made by the user. A CRO is the only accessory that is required. The following studies can be carried out. (i) Reverse saturation current l0 and material constant h(ii) Temperature coefficient of junction voltage dV/dt(iii) Energy band-gap VG0(iv) Junction capacitance The experimental set-up consists of the following: (1) Study of P-N Junctions, Model PN-1 (a) 3 digit DPM for current/ temperature measurement.(b) 3 digit DPM for bias voltage/ junction voltage measurements.(c) To connect the diode one for experiment 1 & 2 and other for experiment 3.(d) Two fixed frequency oscillators (5KHz & 20KHz) with the same output (200mV). (2) Fast temperature controlled oven with sensor, PNO-01 (3) PNJ-Sample (a) Transistor BC109 (base-emitter)-Si(b) Transistor AC128 (base-emitter)-Ge(c) Diode: IN 5408/IN 4002-Si The unit is supplied complete with a detailed instruction manual. Sufficient theoretical description is included for a proper understanding. This is followed by a step-by-step procedure and a typical set of readings and results. The set-up is complete in all respect, except a CRO which is required for measurement of junction capacitance. The experiment is complete in all respect.

We offer Light Intensity Control System useful for control labs. The light intensity control system is designed to bring out the basic features of closed loop systems in the form of a laboratory experiment. The light panel comprises of a number of filament lamps which get power from amplifier. Average intensity of the panel is sensed by a light sensor and a suitable voltage level is produced. Error detector, reference input and error amplifier are of standard configurations found in any linear control system. In addition to the above, the light panel also contains a few uncontrolled lamps which may be used as disturbance source. Further a square wave signal is available for dynamic response studies.Highlights Feedback control of light intensityStudy of inherent non-linearties-sensor, lampsPI controlDynamic response displays >>Experiments Characterization of light panel and light sensor blocksStudy of a practical single loop feedback control system which includes: Disturbance studyError monitoring Performance improvement through P-I controlEvaluation of dynamic behavior >>Features and Specifications Built-in 3 digit DVMBuilt-in IC regulated power suppliesLiterature and patch cords includedSeven lamps 6V/300mA5Hz square wave and triangular wave for dynamic response study The experiment is complete in all respect.

We Offer Apparatus for Measurement of Susceptibility of Paramagnetic Solids By Gouys Method in This, the Solid Sample in the Form of a Long Cylinder (area of Cross Section A) is Hung from the Pan of a Balance and is Placed such that One End of the Sample is Between the Pole-pieces of the Magnet (field H ) and the other One is Outside the Field. the Force Exerted On the Sample By the Inhomogeneous Magnetic Field is Obtained By Measuring the Apparent Change in the Mass of the Sample.the Set Up Consists of the Following:(a) Scientific Balance, Ksb-07Capacity: 200 Gms Sensitivity: 110 Mg. By Vernier Beam: Hard Bronze BrassArrestment: Circular, Falling Away Type Air Damping: Very Quick and Positive, Beam Coming to Rest in 2-3 Sec (b) Sample in the Form of a Long Rod:Set of 4 Samples, 2 Each of Ebonite and Wood(c) Electromagnet, Model Emu-75tPole Pieces: 75mm Tapered to 25mmMag. Field: 20kg At 6mm Air-gapEnergizing Coils: Two of Approx. 13w EachPower: 0-90vdc, 3a, for Coils in Series0-45vdc, 6a, for Coils in Parallel(d) Constant Current Power Supply, Model Dps-175 (e) Gauss-meter, Model Dgm-202 or Dgm-102 the Experiment is Complete in all Respect.

We offer Study of Stepper Motor useful for control labs. This experimental set-up aims at providing an exposure to the basic operation of a stepper motor, its drive and logic, and limitations as far as the internal dynamics is concerned. >>Highlights Stepper motor operation through pulse circuitStepper motor operation through 8085 mp kitBuilt-in programs in EPROMDynamic response study >>Experiments Manual stepping through push button switch. Measurement of step angle.Speed and direction control logic by recording the pulse sequence.Study of resonance effect at various speedsDisplay and measurement of the dynamic characteristics of the motor in the wobble mode.Calculation of single stepping and slew regions.Programming the microprocessor kit to implement features like direction, speed, angle of rotation, number of steps or an arbitrary motionStudy of the effect of inertial and frictional loading on the dynamic performance >>Features and Specifications Single stepping and free running modes of operation with speed variation and direction reversal - internal TTL circuit.360 motion Servo-Potentiometer position -pickup for motor dynamicsOperation through microprocessor kit sample control programs providedStepper motor specification Torque: 2.8 Kg-cmStep angle: 1.8Power: 12V, 1A/phase Essential accessory a CRO The experiment is complete in all respect except a CRO.

We offer Four Probe Method, it is one of the standard and most widely used method for the measurement of resistivity of semiconductors. The experimental arrangement is illustrated. In its useful form, the four probes are collinear. The error due to contact resistance, which is specially serious in the electrical measurement on semiconductors, is avoided by the use of two extra contacts (probes) between the current contacts. In this arrangement the contact resistance may all be high compare to the sample resistance, but as long as the resistance of the sample and contact resistances are small compared withthe effective resistance of the voltage measuring device (potentiometer, electrometer or electronic voltmeter), the measured value will remain unaffected. Because of pressure contacts, the arrangement is also specially useful for quick measurement on different samples or sampling different parts of the same sample. The experiment consists of the following: (i). Four Probes Arrangement, FPA-02:It has four individually spring loaded probes. The probes are collinear and equally spaced. The probes are mounted in a teflon bush, which ensure a good electrical insulation between the probes.A teflon spacer near the tips is also provided to keep the probes at equal distance. The whole arrangement is mounted on a suitable stand and leads are provided for the voltage measurement. (ii). Sample (Ge-n type)Germanium crystal in the form of a chip (iii). Oven FPO-02 (upto 200C)It is a small oven for the variation of temperature of the crystal from the room temperature to about 200C (max.) (iv). Thermometer DFP 02-THR (0-150C) (v). Four Probe Set-up, DFP-02The set-up consists of three units in the same cabinet. (a) Multirange Digital VoltmeterRange: X1 (0-200mV) & X10 (0-2V) Resolution: 100mV at X1 range Accuracy: 0.1% of reading 1 digit Impedance: 1MDisplay: 3 digit, 7 segment LED (b) Constant Current GeneratorOpen Circuit: 18VCurrent range: 0-20mAResolution: 10mAAccuracy: 0.25% of the reading 1 digitLoad regulation: 0.03% for 0 to full loadLine Regulation: 0.05% for 10% changes (c) Oven Power Supply: Built-in for the above oven. Typical results obtained from this set-up are shown in the datasheet. The experimental set-up is complete in all respect.