Deltatron or Engetron

Engetron or Deltatron, Combination of cock-croft walton and cascaded transformers

2. Deltatron
Gohar Arslan (2K11 –EE –022)
Kumail Hassan (2K11 –EE –034)
Usman Masood (2K11 –EE –052)
Abdul Rahman (2K11 –EE –064)
Saad Khurram (2K11 –EE –136)

3. Introduction
Voltage
multiplier
circuits
Cock-Croft
Walton
Multiplier Circuit
Insulated Core
Transformer
Allibone Dynamitron Deltatron

4. Insulated core transformer (ICT)
•Series connection of full wave rectifiers
•Each rectifier produces V
ovoltages and
n rectifiers will produce nV
ovolts.
•All the rectifiers are insulated from
transformer core and from each other

5. Allibone Voltage Multiplier
•Each stage has a HV transformer and
two half wave rectifiers
•Storage capacitors are connected in series
•The main problem in this circuit is the
insulation

6. Dynamitron
•Parallel fed cascade circuit
•High frequency input of MHz
•Load-ability of this circuit is several times
of mA and voltage of MV range
•A Dynamitrontype high voltage power supply
utilized in a neutron generator in operation for 14MeV neutron
therapy at the EppendorfHospital in Hamburg.

7. Deltatron
•It is also called Engetron
•First time it was described by international conference Electronic
Materials and Nanotechnology for Green Environment (Enge) in US
patent
•Combination of Cockcroft-Walton & Cascaded Transformer DC
rectifier
•It has no iron core
•High stability

8. •Small ripple factor
•Fast regulation
•Combined R-C voltage divider is for fast regulation
•This might be limited up to 1 MV and some mA
•Termination circuit is used to stop the process

9. Why not Cockcroft-Walton?
•IfthegeneratorsuppliesanyloadcurrentI,the
outputvoltagewillneverreachthevalue2nV
max
•Therewillalsobearippleonthevoltage
•Thereforewehavetodealwithtwoquantities:
1)VoltagedropΔV
0
2)Peak-to-Peakripple2δV
•Fig.showstheshapeoftheoutputvoltage

11. Equations

12. •Foragivenload,however,V
0mayriseinitiallywiththenumberof
stagesn,butreachesanoptimumvalueandevendecreasesifnistoo
large
•For a generator with V
max= 100 kV
f = 500 Hz
C = 7µF and
I = 500 mA
n
opt= 10
Itis,however,notdesirabletousetheoptimumnumberofstages,as
thenV
0maxisreducedto2/3ofitsmaximumvalue2nV
max.Alsothe
voltagevariationsforvaryingloadswillincreasetoomuch.

13. Voltage Multiplier With Cascaded
Transformers
•DisadvantagecanbereducedofWaltoncircuitifsingle-orfull-wave
rectifiersystems,eachhavingitsownACpowersource,areconnectedin
seriesattheDCoutputonly.
•In this circuit, every transformer per stage consists of a low voltage
primary, a high voltage secondary and a low voltage tertiary coil.
•AsnoneoftheHVsecondarywindingsisongroundpotential,aDC
voltageinsulationwithineachtransformerisnecessary,whichcanbe
subdividedwithinthetransformers.

16. Disadvantage
•Limitations as far as the number of stages is concerned, as the lower
transformers have to supply the energy for the upper ones, this
circuit, excited with power frequency, provides an economical DC
power supply for HV testing purposes with moderate ripple factors
and high power capabilities.

17. Engetron
•Primarily consists of series connected transformers
(without iron-core)
•Transformers are coupled by series capacitors Cs
•Capacitors compensate stray inductance
•Acapacitors Cp is connected in parallel to provide
overcompensation of magnetizing currents
•The chain of transformers is loaded by
terminating resistor

18. Deltatron / Engetron
•Network acts like a terminated transmission line
•E.g. having ac voltages constant and a phase shift
between high frequency supply and termination
•Walton cascaded are directly series connected
providing HVDC output voltage for whole unit
•Frequency oscillator ranges from 50 to 100kHz

19. Deltatron / Engetron
•25 stages can be used in modular structure
•Modules are very small so can be stacked in cylindrical unit
•Insulated by SF
6
•Regulation due to load variations is very small (response time
typically about 1ms)
•For continuous and stable DC output high product of fCis necessary

20. Applications
•Electrostatic printing.
•As a power source of high voltage particle accelerators.
•As a source for electrostatic quadrupolelenses.

21. Limitations
•Decreased stray capacitances due to increased input frequency.
Xc=1/2πfc
•Corona effect.
•Losses due to leakage in diodes, capacitors and insulation are
significant considerations in applications using very low capacitor
values and in applications, which operate at high
temperatures(>125°C).
•Input and output voltages.

22. EnvironmentalLimitations
•Nonlinearcoronaeffectandcontaminationduetodepositing
insulatingfilmarisesduetohighaltitudes.
•Dielectricoilsorgasestosurroundthecustommultiplierassemblyto
provideexcellentisolation,reducedcoronaeffects,minimal
mechanicalstresses,andusuallygoodcooling,theycanalsodamage
ordegradesomeencapsulantsandremoveassembly
labeling.(chemicalexposure).
•Humidityseverelylimitsthevoltageisolationcapabilitiesofair-
insulatedapplications.

23. Environmental Limitations
•High temperatures can induce significant mechanical stresses, due to
mismatches in material thermal expansion coefficient. Similarly, very
low temperature extremes can induce mechanical stresses due to
material thermal expansion mismatches. Low temperatures can also
cause radical changes in the physical characteristics of the
encapsulant, making it brittle, or causing the encapsulantto exhibit
non-linear shrinkage effects.

24. Thank You…!!! 