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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
____________
____________
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
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