“ZENER DIODE TESTER”

INDEX 1. Introduction

2. Circuit Diagram

3. List of Components

4. Working

5. PCB Layout

6. Soldering

a.)PCB Soldering

b.)Types of flux

c.)Types of soldering

7. Practical Application

8. Advantages

9. Precautions

10. Conclusion

INTRODUCTION

The uniqueness of this project is that this is zener diode tester can be used in practical labs to find breakdown voltage of a zener diode.

CIRCUIT DIAGRAM

LIST OF COMPONENTS

Part TotalQty.

Description

Resistance(R1) 1 1 KΩResistance(R2) 1 1 MΩResistance(R3) 1 10 KΩ VR1 1 10 K POT Capacitor(C1) 1 1µF/160V Capacitor(C2) 1 0.68µF/250V Capacitor(C3) 1 470µF/25V Diode(D1) 1 1N4007 Transistor(T1) 1 BC547

Transformer 1 9V-0-9V,500mASwitch 1 On/off

Zener

WORKING

Here is a handy zener diode tester which tests zener diodes with breakdown voltages extending up to 120 volts. The main advantage of this circuit is that it works with a voltage as low as 6V DC and consumes less than 8 mA current. The circuit can be fitted in a 9V battery box. Two-third of the box may be used for four 1.5V batteries and the remaining one-third is sufficient for accommodating this circuit. In this circuit a commonly available transformer with 230V AC primary to 9-0-9V, 500mA secondary is used in reverse to achieve higher AC voltage across 230V AC terminals. Transistor T1 (BC547) is configured as an oscillator and driver to obtain required AC voltage across transformer’s 230V AC terminals. This AC voltage is converted to DC by diode D1 and filter capacitor C2 and is used to test the zener diodes. R3 is used as a series current limiting resistor. After assembling the circuit, check DC voltage across points A and B without connecting any zener diode. Now switch on S1. The DC voltage across A-B should vary from 10V to 120V by adjusting potmeter VR1(10k). If every thing is all right, the circuit is ready for use. For testing a zener diode of unknown value, connect it across points A and B with cathode towards A. Adjust potmeter VR1 so as to obtain the maximum DC voltage across A and B. Note down this zener value corresponding to DC voltage reading on the digital multimeter. When testing zener diode of value less than 3.3V, the meter shows less voltage instead of the actual zener value. However, correct reading is obtained for zener diodes of value above 5.8V with a tolerance of ± 10per cent. In case zener diode shorts, the multimeter shows 0 volts.

PCB LAYOUT

SOLDERING It is a process of joining two metallic components at a relative low

temp of 600⁰K. The joints are called Alloy of joint and lead solder. The insulating rods and materials required for soldering are as follows:-

Soldering Iron: It consist of

Supply end + plug Wooden or plastic handle Metallic shift containing heating element metallic copper

etc.

SOLDER- It is an alloy of tin or lead. Melting point operates on Ratio of tin& Lead. Grades of soldier contain % of tin & lead respectively.

SOLDER FLUX-A soldier flux of plate is generally used for soldering the flux, meet & line surface of any oxide film to ensure the smoothness of Soldering.

PCB SOLDERING

A dirty light soldering made of 25w to 30w should be used to prevent damage to printed circuit.

Do not use excess wire. Soldering wire should have thin tip. When soldering a semiconductor device hold the component

to the Solder with a pair of longer file as clips (Heat sink) to prevent damage

TYPES OF FLUX:-

1. Flux consists of organic acids and salts generally used to add different materials when rapid cutting of 1 is required .Most organic ingredient are 2nCb since it melts at soldering temperature and form a convenient source of HCL to perform fluxing action.

2.Intermediate flux-They are weak in nature. They are active at soldering temperature but some of them have the active period in short because they are volatile.

3. Non-corrosive flux-For delicate instrument where it is difficult to waste residue after soldering is required pure water while an 20-25% delivered is a solvent like iso propane chain approach to a non-corrosive flux solution.

Types of Soldering

1. Man soldering-It is incorporate technique where a large no. of parts is made simultaneously using soldering both.

2. Drag soldering-A conveyer system is used to mount so that it performs usually over a fluxing station. A flux layer as per heating and flux over a surface of long soldered path. At the beginning a board is lowered at small flux horizontally along the solder surface.

3.Dip Soldering-The pre flux assembly is to vertically in to clean solder surface whit it contact and flux remove in soldier both required to depth.

4. Wave Soldering-Instead of lowering board path solder is pumped out of a narrow slot and creates a standing wave in soldering paths.

PRACTICAL APPPLICATION

In practical labs sometimes it is necessary and very difficult to find breakdown voltage of a zener diode. Then this circut will be helpful to us .

ADVANTAGE

The main advantage of this circuit is that it works with a voltage as low as 6V DC and consumes less than 8 mA current. The circuit can be fitted in a 9V battery box. Two-third of the box may be used for four 1.5V batteries and the remaining one-third is sufficient for accommodating this circuit.

PRECAUTIONS: The circuit carries 230V AC and most of its points are at mains lethal potential do not touch any point in the circuit when it is powered

CONCLUSION:During our tenure of group project we realised that practical knowledge is considered to be vital and evitable role to perform for every individual to learn anything in this world.

By doing this project we could turn our theoretical knowledge to reality. It works as cement lining that holds the bricks of theoretical knowledge together. This project uplifted our confident to work as team and improves our practical knowledge.

We are sure that after completing this project successfully we will be able to work in any organization effectively. Each stage was a unique experience to enrich our knowledge.

REFERENCE

1. ELECTRONICS FOR YOU Magazine.

2. www.efymag.com.