- The document describes different types of voltage multiplier circuits including Cockcroft-Walton, insulated core transformer, Allibone, Dynamitron, and Deltatron circuits. - The Deltatron circuit is a combination of Cockcroft-Walton and cascaded transformer DC rectifier circuits that has no iron core, high stability, small ripple factor, and fast regulation. - It uses a chain of coupled transformers to generate high voltage DC and can achieve output voltages up to 1 MV and currents of some mA.

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 Vo voltages and
n rectifiers will produce nVo volts.
• 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 Dynamitron type high voltage power supply
utilized in a neutron generator in operation for 14MeV neutron
therapy at the Eppendorf Hospital 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?
• If the generator supplies any load current I, the
output voltage will never reach the value 2nVmax
• There will also be a ripple on the voltage
• Therefore we have to deal with two quantities:
1) Voltage drop ΔV0
2) Peak-to-Peak ripple 2δV
• Fig. shows the shape of the output voltage

11. Equations

12. • For a given load, however, V0 may rise initially with the number of
stages n, but reaches an optimum value and even decreases if n is too
large
• For a generator with Vmax= 100 kV
f = 500 Hz
C = 7µF and
I = 500 mA
nopt= 10
It is, however, not desirable to use the optimum number of stages, as
then V0max is reduced to 2/3 of its maximum value 2nVmax. Also the
voltage variations for varying loads will increase too much.

13. Voltage Multiplier With Cascaded
Transformers
• Disadvantage can be reduced of Walton circuit if single- or full-wave
rectifier systems, each having its own AC power source, are connected in
series at the DC output only.
• In this circuit, every transformer per stage consists of a low voltage
primary, a high voltage secondary and a low voltage tertiary coil.
• As none of the HV secondary windings is on ground potential, a DC
voltage insulation within each transformer is necessary, which can be
subdivided within the transformers.

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
• A capacitors 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 SF6
• Regulation due to load variations is very small (response time
typically about 1ms)
• For continuous and stable DC output high product of fC is necessary

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

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. Environmental Limitations
• Non linear corona effect and contamination due to depositing
insulating film arises due to high altitudes.
• Dielectric oils or gases to surround the custom multiplier assembly to
provide excellent isolation, reduced corona effects, minimal
mechanical stresses, and usually good cooling, they can also damage
or degrade some encapsulants and remove assembly
labeling.(chemical exposure).
• Humidity severely limits the voltage isolation capabilities of air-
insulated applications.

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 encapsulant to exhibit
non-linear shrinkage effects.

24. Thank You…!!! 