diac characteristic trainer nv6531 - cgi bharatpur, best

DIAC Characteristic TrainerNV6531

Learning Material

Ver 1.1

141-B, Electronic Complex,

Pardeshipura, Indore- 452 010 India

Tel.: 91-731- 4211500

Toll-free:1800-103-5050

Email: [email protected]

Website: www.nvistech.com

mailto:[email protected]

NV6531

Nvis Technologies Pvt. Ltd. 2

DIAC Characteristic TrainerNV6531

Table of Contents

1. Introduction 3

2. Features 4

3. Technical Specifications 5

4. Theory 6

5. Experiment 9To study the VI Characteristic of DIAC with positive biasing and plot thecurve between V & I.

6. Warranty 13

7. List of Accessories 14

www.nvistech.com

NV6531


Introduction

“NV6531 DIAC Characteristic Trainer” is remarkable and frequently used laboratoryequipment which is designed to explain basic fundamentals of DIAC and theirworking. Using this Trainer student can understand the basic concept of DIAC whichis a basic part of Power Electronics. A VI Characteristic can be drawn by the studentwhich helps students to understand the behaviour of DIAC.

NV6531


Features

A low cost trainer demonstrating VI Characteristic of DIAC.

Exclusive presentation and easy illustration.

Provided with inbuilt Power supply of +35V & -35V.

DPM Based Highly preceised Voltmeter & Ammeter.

Learning Material CD

2 year warranty

NV6531


Technical Specification

Mains Supply : 230 V AC ±10%, 50 Hz

Power Supply Output : +35V DC (250 mA)

-35V DC (250 mA)

Voltmeter : 0-35V (max.)

Ammeter : 0-50mA (max.)

Dimensions (mm) : 345×240×110

NV6531


TheoryPower Electronics:

Introduction:Power electronic converters can be found wherever there is a need to modify theelectrical energy form (i.e modify its voltage, current or frequency). Therefore, theirpower range from some milliwatts (as in a mobile phone) to hundreds of megawatts(e.g in a HVDC transmission system). With "classical" electronics, electrical currentsand voltage are used to carry information, whereas with power electronics, they carrypower.

The first very high power electronic devices were mercury arc valves. In modernsystems the conversion is performed with semiconductor switching devices such asdiodes, thyristors and transistors. In contrast to electronic systems concerned withtransmission and processing of signals and data, in power electronics substantialamounts of electrical energy are processed. An AC/DC converter (rectifier) is themost typical power electronics device found in many consumer electronic devices,e.g., television sets, personal computers, battery chargers, etc. The power range istypically from tens of watts to several hundred watts. In industry the most commonapplication is the variable speed drive (VSD) that is used to control an inductionmotor. The power range of VSDs start from a few hundred watts and end at tens ofmegawatts.

The power conversion systems can be classified according to the type of the input andoutput power

AC to DC (rectification)

DC to AC (inversion)

DC to DC (chopping)

AC to AC

Principle:

As efficiency is at a premium in a power electronic converter, the losses that a powerelectronic device generates should be as low as possible. The instantaneous dissipatedpower of a device is equal to the product of the voltage across the device and thecurrent through it (P = VI). From this, one can see that the losses of a power deviceare at a minimum when the voltage across it is zero (the device is in the On-State) orwhen no current flows through it (Off-State). Therefore, a power electronic converteris built around one (or more) device operating in switching mode (either On or Off).With such a structure, the energy is transferred from the input of the converter to itsoutput by bursts.

NV6531


Applications:

Power electronic systems are virtually in every electronic device. For example,around us:

DC/DC converters are used in most mobile devices (mobile phone, pda.) tomaintain the voltage at a fixed value whatever the charge level of the batteryis. These converters are also used for electronic isolation and power factorcorrection.

AC/DC converters (rectifiers) are used every time an electronic device isconnected to the mains (computer, television,...)

AC/AC converters are used to change either the voltage level or the frequency(international power adapters, light dimmer). In power distribution networksAC/AC converters may be used to exchange power between utility frequency50 Hz and 60 Hz power grids.

DC/AC converters (inverters) are used primarily in UPS or emergency light.During normal electricity condition, the electricity will charge the DC battery.During blackout time, the DC battery will be used to produce AC electricity atits output to power up the appliances.

DIAC

The DIAC, or diode for alternating current, is a trigger diode that conducts currentonly after its breakdown voltage has been exceeded momentarily. When this occurs,the resistance of the diode abruptly decreases, leading to a sharp decrease in thevoltage drop across the diode and, usually, a sharp increase in current flow throughthe diode. The diode remains "in conduction" until the current flow through it dropsbelow a value characteristic for the device, called the holding current. Below thisvalue, the diode switches back to its high-resistance (non-conducting) state. Thisbehavior is bidirectional, meaning typically the same for both directions of currentflow.

Most DIACs have a breakdown voltage around 30 V. In this way, their behavior issomewhat similar to (but much more precisely controlled and taking place at lowervoltages than) a neon lamp.

DIACs have no gate electrode, unlike some other thyristors they are commonly usedto trigger, such as TRIACs. Some TRIACs contain a built-in DIAC in series with theTRIAC's "gate" terminal for this purpose.

DIACs are also called symmetrical trigger diodes due to the symmetry of theircharacteristic curve. Because DIACs are bidirectional devices, their terminals are notlabeled as anode and cathode but as A1 and A2 or MT1 ("Main Terminal") and MT2.

NV6531


Symbol of DIAC:

The basic arrangement of the semiconductor layers of the DIAC is shown in figure

Figure 1

where:

T1 : Main Terminal 1

T2 : Main Terminal 2

DIAC is basically a two terminal parallel inverse combination of semiconductor layerthat permits triggering in either direction. The characteristic of the device clearlydemonstrated that there is breakdown voltage in either direction.

DIAC Characteristics:

Figure 2

NV6531


Experiment

Objective :To study the VI Characteristic of DIAC with positive biasing and plot the curvebetween V & I.

Apparatus Required :

1. NV6531 DIAC Characteristic Trainer

2. 2mm Patch Cord

Circuit Diagram:

Figure 3

Procedure:

Positive Biasing:

1. Make the connections as shown in the above figure.

2. Connect the +35V DC supply to the circuit by connecting the point 1 withpoint 4 with the help of patch cord.

3. Rotate the potentiometer P1 in fully anti-clock wise direction.

4. Now connect point 2 with point 8 to make the grounds common.

NV6531


5. Connect the voltmeter across the DIAC. For that connect the +Ve terminal ofVoltmeter with the point 7 and connect the -Ve terminal of the voltmeter withthe point 8.

6. Now connect the Ammeter in the circuit for that connect the +Ve terminal ofthe ammeter to the point 5 and connect the -Ve terminal of the Ammeter to thepoint 6.

7. Connect the mains cord to the trainer & switch ‘On’ the supply.8. Here you will observe that there is no current flow in the circuit and as well as

no voltage across the DIAC.

9. Increase the voltage across the DIAC in steps of 1V by rotating the potentiometerP1 in clockwise direction and note down the readings for Voltage and Current inthe following table.

10. Now plot the VI curve for taken readings.

Observation Table 1:

Serial Number DIACEVoltage Va

DIACECurrent Ia

DIACEVoltage -Va

DIACECurrent Ia

1

2

3

4

5

6

7

8

9

10

NV6531


Negative Biasing:

10. Now connect the -35V DC supply to the circuit by connecting the point 3with point 4 with the help of patch cord.

11. Repeat the process from step 3 to step 9.

12. Now plot the VI curve for taken readings.

Result Analysis:

VI Characteristic with Positive Biasing

Sr.No. DAIC VoltageVa (in Volt)

DIAC CurrentIa (in mA)

1 0 0

2 1 0

3 2 0

4 3 0

5 4 0

6 5 0

7 6 0

8 7 0

9 8 0

10 9 0

11 10 0

12 11 0

13 12 0

14 13 0

15 14 0

16 15 0

17 16 0

18 17 0

19 18 0

20 19 0

21 20 0

22 21 0

23 22 0

24 23 0

25 24 0

26 25 0

27 26 0

28 27 0

29 28 0

30 29 0

31 30 0

32 30.9 0

33 20.6 6.78

34 20.1 10.42

35 19.9 13.64

36 19.7 15.41

NV6531


VI Characteristic with Negative Biasing

NV6531


Warranty

1. We guarantee the instrument against all manufacturing defects during 24months from the date of sale by us or through our dealers.

2. The guarantee covers manufacturing defects in respect of indigenouscomponents and material limited to the warranty extended to us by the originalmanufacturer 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 learningmaterial.

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 immediatelygiving full details of the complaints and defects noticed specificallymentioning the type and sr. no. of the

5. instrument, date of purchase etc.

6. The repair work will be carried out, provided the instrument is dispatchedsecurely packed and insured with the railways. To and fro charges will be tothe account of the customer.

DISPATCH PROCEDURE FOR SERVICE

Should it become necessary to send back the instrument to factory please observe thefollowing procedure.

1. Before dispatching the instrument please write to us giving full details of thefault noticed.

2. After receipt of your letter our repairs dept. will advise you whether it isnecessary to send the instrument back to us for repairs or the adjustment ispossible in your premises.

Dispatch the instrument (only on the receipt of our advice) securely packed in originalpacking duly insured and freight paid along with accessories and a copy of the detailsnoticed to us at our factory address.

NV6531


List of Accessories

1. Mains Cord……………………………………………………………...1 No.

2. 2mm Patch Cords 12”………………………………………………….10 Nos.

3. Learning Material CD………………………………………………….1 No.

diac characteristic trainer nv6531 - cgi bharatpur, best

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