SHRI G.S. INSTITUTE OF TECHNOLOGY AND SCIENCE

DEPARTMENT OF ELECTRONICS AND TELECOMMUNICATION ENGINEERING

A PROJECT REPORT

ON “VOLTAGE DOUBLER”

SUBMITTED TO :- SUBMITTED

BY :- DEEPAK KUSHWAH

JAGDISH PAUL VIKASH SINGH

VIKRAM PAUL

Table of contents

● Acknowledgment ● Component used ● Introduction ● Types of voltage multiplier ● Circuit diagram ● Working ● Applications ● Bibliography

ACKNOWLEDGEMENT

I am glad to my gratitude to all those helped me in drafting this report and in making of this project on

“voltage doubler”. We thank Mr.--------- sir for

helping us draft this report and in making of our project. We would like to thank all the professors and staff members who helped us. We also thank our family members and friends who guided us and provided us the necessary resources which proved valuable in completion of the report and project.

CERTIFICATE This is to certify that DEEPAK KUSHWAH, JAGDISH PAUL, VIKASH SINGH, VIKRAM GURJAR of S.G.S.I.T.S. studying in BE IInd year in july to november 2014-15

____________

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COMPONENTS USED  PCB (PRINTED CIRCUIT BOARD)    A printed circuit board (PCB) mechanically supports and electrically connects electronic                     

components using conductive tracks, pads and other features etched from copper sheets                       

laminated onto a non­conductive substrate. PCBs can be single sided (one copper layer),double                         

sided (two copper layers) or multi­layer. Conductors on different layers are connected with                         

plated­through holes called vias. Advanced PCBs may contain components ­ capacitors,                     

resistors or active devices ­ embedded in the substrate. 

 

Dotted PCB 

Printed circuit boards are used in all but the simplest electronic products. Alternatives to PCBs                             

include wire wrap and point­to­point construction. PCBs require the additional design effort to lay                           

out the circuit but manufacturing and assembly can be automated. Manufacturing circuits with                         

PCBs is cheaper and faster than with other wiring methods as components are mounted and                             

wired with one single part. Furthermore, operator wiring errors are eliminated. 

 

 

 

DIODES 

A diode allows        electricity to flow     

in one direction only        and blocks the     

flow in the opposite        direction. They   

may be regarded as        one­way valves   

and they are used in          various circuits,   

usually as a form of          protection. There   

are different types of        diode but their     

basic functions are      the same.  

 

CAPACITOR 

A capacitor (originally known as a condenser) is a passive two­terminal                       electrical component used to store energy electrostatically in an electric field. The forms of                           practicalcapacitors vary widely, but all contain at least two electrical conductors (plates)                       separated by a dielectric (i.e. insulator). 

 

 

   

TRANSFORMER

A transformer is an electrical device that transfers energy                   

between two or more circuits through electromagnetic induction. 

A varying current in the transformer's primary winding creates a varying                     

magnetic flux in the core and a varying magnetic field impinging on the                         

secondary winding. This varying magnetic field at the secondary induces a                     

varying electromotive force (emf) or voltage in the secondary winding.                   

Making use of Faraday's Law in conjunction with high magnetic                   

permeability core properties, transformers can thus be designed to                 

efficiently change AC voltages from one voltage level to another within                     

power networks. 

INTRODUCTION  

A voltage doubler is an electronic circuit which charges capacitors from                     

the input voltage and switches these charges in such a way that, in the                           

ideal case, exactly twice the voltage is produced at the output as at its                           

input. 

The simplest of these circuits are a form of rectifier which take an AC voltage as input and                                   

output a doubled DC voltage. The switching elements are simple diodes and they are                           

driven to switch state merely by the alternating voltage of the input. DC to DC voltage                               

doublers cannot switch in this way and require a driving circuit to control the switching. They                               

frequently also require a switching element that can be controlled directly, such as a                           

transistor, rather than relying on the voltage across the switch as in the simple AC to DC                                 

case. 

Voltage doublers are a variety of voltage multiplier circuit. Many (but not all) voltage doubler                             

circuits can be viewed as a single stage of a higher order multiplier: cascading identical                             

stages together achieves a greater voltage multiplication. 

Voltage Doubler is a voltage multiplier circuit which has a voltage multiplication factor of                           two. The circuit consists of only two diodes, two capacitors and an oscillating AC input                             voltage (a PWM waveform could also be used). This simple diode­capacitor pump circuit                         gives a DC output voltage equal to the peak­to­peak value of the sinusoidal input.     

CIRCUIT DIAGRAM     

WORKING   The circuit shows a half wave voltage doubler. During the negative half cycle of the sinusoidal input                                   

waveform, diode D1 is forward biased and conducts charging up the pump capacitor, C1 to the peak value of                                     the input voltage, (Vp). Because there is no path for capacitor C1to discharge into, it remains fully charged                                   and acts as a storage device in series with the voltage supply. At the same time, diode D2 conducts via D1                                         charging up capacitor, C2. 

During the positive half cycle, diode D1 is reverse biased blocking the discharging of C1 while diodeD2 is                                   forward biased charging up capacitor C2. But because there is a voltage across capacitor C1already equal                               to the peak input voltage, capacitor C2 charges to twice the peak voltage value of the input signal. 

In other words, V(positive peak) + V(negative peak) as on the negative half­cycle, D1 charges C1 toVp and                                   on the positive half­cycle D2 adds the AC peak voltage to Vp onC1 and transfers it all to C2. The voltage                                         across capacitor, C2 discharges through the load ready for the next half cycle. 

Then the voltage across capacitor, C2 can be calculated as: Vout = 2Vp, (minus of course the voltage drops                                     across the diodes used) where Vp is the peak value of the input voltage. Note that this double output voltage                                       is not instantaneous but increases slowly on each input cycle, eventually settling to 2Vp. 

As capacitor C2 only charges up during one half cycle of the input waveform, the resulting output voltage                                   discharged into the load has a ripple frequency equal to the supply frequency, hence the name half wave                                   voltage doubler. The disadvantage of this is that it can be difficult to smooth out this large ripple frequency in                                       much the same way as for a half wave rectifier circuit. Also, capacitorC2 must have a DC voltage rating at                                       least twice the value of the peak input voltage. 

 

Application 

Voltage multipliers are used in high voltage, low current applications such as for accelerating 

purpose in a cathode ray tube. Generally these are used where both the supply voltage and load 

are maintained constant. 

Voltage doublers are extensively used in television and radar equipments as an alternative to 

heavier, larger, and expensive transformer and rectifier arrangements, which also perform the 

same function as that of voltage doublers. 

    

BIBLIOGRAPHY   

➢  http://en.wikipedia.org/wiki/Voltage_doubler ➢ http://en.wikipedia.org/wiki/Capacitor ➢ http://www.technologystudent.com/elec1/diode1.htm ➢ http://www.electronics­tutorials.ws/blog/voltage­multiplier­circuit.html ➢ APPLIED ELECTRONICS BY R.S. SEDHA ➢ INTERNET RESOURCES