A Guide to online information
A couple of items set me on the path
to look into the realm of High Voltage this month. The first being
that I had a simple home experiment project and needed to power a
NE2 (A1A) neon bulb, where I needed to get up to 100VDC to get the
bulb to strike, the second being I needed to track down some High-Voltage
*AC* capacitors for my job in the
Real World. So I thought I'd do this month's topic on High Voltage.
When I asked Steve what he thought of the idea, he asked in effect
what is 'High'? In some systems today 5VDC is a High Voltage.
Is saying High Voltage like saying, "How
high is up?" Does an official definition
for High Voltage exist?
When I come up against such a high-voltage
question, the first place I turn is usually the High Voltage mailing
list. The HV list is archived at http://anchorage.ab.umd.edu/hvlist.html
and is currently unindexed and unsearchable, but is collected into
months and available for download.
If you're interested in joining this
mailing list, e-mail Steve Roys, at email@example.com
You can also find the Richard
Hull/TCBOR Budget Electrometer construction project in the HV
This is the question I posed on the High
Voltage list, and the replies that I received. Slightly edited to
remove non-pertinent information:
>I thought I'd do a Resource Page that
>topic of High Voltage.
>This begs the question what is High Voltage?
>Is there an official definition or starting voltage?
>In some of today's modern computer
>systems 5VDC would be considered high
>enough voltage to damage the system.
>If any one has any links to High Voltage sites,
>I'd love to have them. Nothing like having lots
>of people help with your homework
>now is there? :-)
From: Jim Lux ---
My site: http://home.earthlink.net/~jimlux/hv/hvmain.htm
The electrical code considers HV anything
over 50 V, 300 V or 600 V, depending on where it is.
Most cheap wire is rated at 300 V. My
own general guideline is that when corona and surface leakage become
a problem, and you can't just use ordinary hookup wire, it is HV,
which is around 3-5 kV.
[Jim covers something I've always personally
found interesting: Electro-optical
measurements (Kerr, Pockels, and Faraday). All of these techniques
rely on various mechanisms by which a material rotates the polarization
of light passing through. The amount of rotation depends on the electric
or magnetic field.]
Jim's page serves as a repository for
all the bits and pieces he is collecting towards creating a modern
version of the classic 1954 work by Craggs and Meek: High Voltage
Laboratory Technique. That work, long out of print, but available
from good university libraries, provided a wealth of practical information
to those interested in experimentation with high voltage, either for
itself, or as a necessary component of some other experiment. However,
back in 1954, they didn't have high-voltage silicon rectifiers, nor
were such modern construction materials as Teflon, Silicone Elastomers,
and fiberglass structural components available.
Maybe you have something that you can
contribute to the project.
From: Richard Hull --- No definition
of high voltage is suitable. It is, of course, relative.
If one figures HV starts where you get
a shock or at least feel the voltage on dry skin, then 50-70 V would
be HV. I would think this list considers 1 KV the lowest voltage to
call HV, with 10 KV being the point where you are really just starting
to talk turkey about high voltage. Many of this list's folks who often
discuss van Degraf generators, multipliers, or Tesla coils would probably
consider 100,000 V a fairly wimpy high voltage.
A good site to add to your list would
be Jochen Kronjaegers web page. http://www.mathematik.unimarburg.de/~kronjaeg/hv/
From: Antonio Carlos M. de Queiroz ---
A reasonable definition would be: High
enough to cause sparks.
This means, in air, electric fields greater
than about 30 kV/cm, and voltages above ~300 V (there are no sparks
in air at voltages below a value close to 300 V [I don't have at hand
the exact value, or how it varies], no matter what the electric field
My site about electrostatic machines
is at: http://www.coe.ufrj.br/
~acmq/electrostatic.html [He has more types of Electrostatic Machines
than I knew existed.]
From: Robert Michaels --- "It's all relative."
A hundred volts will seem quite high
to someone accustomed to working with, say, 3-V integrated circuits.
- - - - - - - -
I come from the old school. To me a voltage
has to be capable of jumping a gap to be considered high. The minimum
voltage required to jump a pair of needle gaps in dry air at STP is
approximately 350-V. That is the lowest high voltage (or the highest
low voltagetake your pick).
PS: Under reduced pressure, a rather
lowish voltage will jump an appreciable gap. For example, 100-V is
good for a solid 1/8" jump at around several millimeters of mercury.
This poses quite a problem in the design
of airborne electronics for use in high-altitude craft.
It also explains (in part) why cosmic
rays can really light up the atmosphere at extreme altitudes but don't
do diddly-squat down here at ground level where we could enjoy the
Likewise, it's why you have to climb
the high mountains (such as Pike's Peak in Colorado) if you want to
see really good lightning displays.
From: "Dr. Resonance" ---
In the industrial sense, HV means any
potential above 208/220/ 240 VAC. The next level is usually 480 VAC
and this is considered high voltage from an industrial standpoint
(i.e., for insurance matters, etc.). Companies that sell "Danger:
High Voltage" industrial stickers/decals usually start also at the
480-V level (i.e., you can purchase Danger: High Voltage 480 V, but
not such stickers for 220 V, etc.).
Rather than the usual disclaimer of High
Voltage Can Lead To Injury or Death, I thought I'd
put some links to pictures of HV Electrical burns and electrical flash
burns, taken from a medical database, to make the point that this
hobby (or profession) has the potential to kill those who do not respect
the voltages and currents involved.
The pictures gave me nightmares, so I
decided against including them. Once you put something like that into
your head it is very hard to take it out.
The Department-of-Energy Electrical
Safety handbook is worth a review (324 pages, PDF 1543 KB DOE-HDBK-1092-98).
Some other DOE hand books of interest:
Fundamentals Handbook, Classical Physics (142 pages, PDF 1120KB
Fundamentals Handbook, Electrical Science, Volume 1 of 4 (166
pages, PDF 4255KB, DOE-HDBK-1011/1-92).
Fundamentals Handbook, Thermodynamics, Heat Transfer, and Fluid Flow,
Volume 1 of 3 (138 pages, PDF 2994 KB, DOE-HDBK-1012/1-92).
Online Approved DOE Technical Standards can be found here.
To see a good FAQ on High Voltage safety,
go to: http://www.pupman.com/safety.htm
The first approach I tried for my Neon
Bulb power supply was to use National
Semiconductor's LM317HV part, based on their Linear
Brief #47 High Voltage Adjustable Power Supplies (pdf). Although
the circuit worked, it had the annoying habit of exploding every once
in a while when turning it on. That is the price you pay for using
leftover transistors from the junk box. After rebuilding the circuit
a couple of times, I decided that there must be alternatives to this
High-Voltage regulator circuit.
I found that the Texas
adjustable three-terminal High-Voltage regulator had the output range
of 1.25 V to 125 V that I was looking for. The circuit worked fine,
no more random explosions at powerup, but I was still not happy. The
TL783 has a minimum load requirement of 15 mA to maintain regulation.
My Neon Bulb load required at most 1 mA, leaving me to waste 14 mA.
Because I wanted to run off of a series of 9-V batteries, this did
not make me a happy camper.
I finally found the solution in Supertex's
Constant Current Sources and Depletion-Mode FETs application notes
(pdf) and AN-D18
(pdf). [For those not familiar with Depletions-Mode FETs, these
FETs are normally on. Most of the FETs you see in 99% of circuits
are Enhancement-Mode FETs that are normally off.]
entire line of products, such as FETS and ICs, is oriented toward
the High-Voltage (up to 500 V) spectrum. They also have a many useful
High Voltage application notes, such as �500
Volt Protection Circuit and High
Voltage Ramp Generator.
High Voltage Component
High Voltage is the world leader in high-voltage power supplies
and can meet virtually every power supply requirement, from lab to
OEM. Their industrial customers use Bertan standard and/or custom
product in applications as diverse as: medical instrumentation, medical
x-ray imaging, analytical x-ray, elemental analysis, semiconductor
fabrication, precision CRT displays, biochemistry instrumentation,
nuclear instrumentation and detectors, scanning electron microscopes,
ATE, E-Beam and I-Beam applications.
Electronics Inc. manufactures precision resistors and resistor
networks. Caddock uses unique film and process technologies to create
solutions for harsh environments, high-power density, and long-term
stability. The product line consists of over 250 models, including
high-voltage resistors, current-sense resistors, chip resistors, high-frequency
resistors, RF resistors, load resistors, pulse resistors, non-inductive
power resistors. Custom resistors and resistor network solutions are
Corporation offers two extensive families of electronic devicesCeramic
Disc Capacitors and PTC Thermistors.
Electronics, Inc. manufactures high-voltage mica paper capacitors
and electronic modules.
is now the world's third largest manufacturer of surge arrester gas
tubes. Citel is also a major supplier to the wireless industry and
has developed a complete surge protection package for AC power, T1,
and coaxial cables.
Motion offers a line of High-Voltage
is a leading manufacturing resource of standardized and customized
precision, high-voltage, high-power non-inductive thick film resistors.
High Voltage Corporation claims to have the world's
smallest 5,000-V power supply at just 0.125 cubic inches.
Devices, Inc. offers High-Voltage diode assemblies, such as 3
A @ 50 kV. They also offer special devices such as night vision diodes
Associates, Inc. and CKE Inc. specialize in custom devices, as
well as High-Current rectifiers, Selenium surge suppressers, MOVs,
TVPs, and Full Wave Bridges.
High Voltage/Fast Recovery Diodes (up to 12 kV).
Voltage Film Capacitor
Voltage Technology: High Voltage products for science and industry
HVT represents a number of manufacturers worldwide, bringing together
an impressive list of principals and serving customers needs with
these High Voltage products:
Capacitors - NWL Inc.
Cable - Dielectric Sciences Inc.
Diodes - HVCA Inc.
Resistors - Victoreen Inc.
Pulse transformers - Stangenes Industries Inc.
Attenuators - Barth Electronic Inc.
Pulse generators - Kentech Instruments Ltd.
Rotary switches - High Voltage Technology
offers High-Voltage multilayer SMT ceramic chip capacitors in voltages
up to 5 kV.
The business of John
Chubb Instrumentation is the design, development, manufacture,
and marketing of high-performance instruments for electrostatic measurements.
The JCI 131 Electrostatic Fieldmeter is particularly suitable for
long-term continuous monitoring of atmospheric electric field conditionssuch
as those associated with thunderstorm and volcano activity.
M Electronics, Inc. has a number of High
Voltage items such as power supplies, electron multipliers, and
componentsprecision high-voltage resistors, ceramic capacitors,
diode arrays, voltage dividers, and custom hybrids.
is a supplier of all types of high-voltage and radio-frequency
Electronics, the Lambda Group can provide power solutions ranging
from a few watts of DC, to DC on a single chip, to over 1 MW of High
Voltage in a turnkey system, as well as capacitor charging power supplies.
J. Lesker Company deals in vacuum equipment.
Energy Products, Inc. makes High-Voltage capacitors, High-Voltage
fuses, and High-Voltage resistors. Alas, it took me a long time to
actually find the relevant web
site from their home page. Surplus
Sales of Nebraska gave me the relevant information about Maxwell
High-Voltage capacitors that I needed quickly, rather than a lot
of non-relevant financial information. Too bad more engineers don't
design web sites for these companies.
also makes capacitor charging power supplies, spark gap switches,
trigger generators, arc lamp power supplies, and nuclear event detectors.
In some areas of High Voltage there are
items that don't exist "off the shelf" and you have to build them
yourself. Tedd Payne
sells some of the most interesting High-Voltage parts you're likely
to need. There are also items wanted (to buy or trade for) and
automatic update notification of newly listed items available from
Tedd's site. Check his links
to other HV sites as well.
Materials Corporation has a nice table to be used as a Ceramic
Engineering Corporation of Campbell, California, designs, tests,
and manufactures High-Voltage Devices. Systems, control, measurement
and safety equipment, and energy sources are marketed world-wide.
Typical applications are in HV power supplies, cyclotrons, lasers,
radar, TV, and high power communication transmitters; almost any equipment,
industrial plant or utility where high voltage or high current is
High-Voltage Electronics is your source for high-voltage power
supplies for OEM, laboratory, and PCB mount applications.
Inc. is a world-leading manufacturer of High-Voltage power supplies
ranging from 62 V to 35 kV, in miniature "palm of the hand" sizes
for power levels ranging from 4 to 250 Watts.
With the name of Voltage
Multipliers Inc., you can probably guess that they sell voltage
multipliers, but they also sell, diodes, rectifier assemblies, and
Components has High-Voltage/High-Value
Resistors (Over 1 GOhms, up to 50 kV).
Brush's electricity page has pictures of HVcomponents as well
as covering Tesla Coil, Arc Lamps, Jacob's Ladders, Stress Tests,
and Cooking With HV.
Applications of High
We've all seen them as we drive along
the road, the big substation transformers. But, if you don't work
in the industry you probably never knew where to buy this kind of
equipment, until now.
is a globalized technology and engineering company serving customers
in power transmission and distribution. They have a paper Why
HVDC? giving the reasons behind a choice of HVDC instead of
AC in the cases of power distribution. You can learn more about HVDC
in the tutorial "Understanding
The Instrument Transformer of ALSTOM
Transmission and distribution satisfies all of the needs for metering
or relaying applications in high-voltage networks.
Electricity Forum Web Site covers, you guessed it, electricity.
More accurately, the electricity industry.
has a link directory, a buyers guide, and a resource locator for the
electrical power industry. . . thousands of links . . .
If you design, manufacture, construct,
startup, test, repair, service, calibrate, maintain, or sell electrical
equipment, power apparatus, plant electrical facilities or generation,
transmission or distribution equipment or systems, ElectricNet's 5,500+
pages are your gateway to valuable industry information.
Does your job seem like something right
from a Dilbert cartoon? Maybe
you'd like training in a new field? Graduates from the High
Voltage electricity program can look forward to and expect career
opportunities with public service companies, utility construction
companies, and power generating companies.
Voltage control and monitoring tutorial.
Bob Kruger has a tutorial x-ray
production, one of the areas where High Voltage is used.
High Voltage Page covers several items of interest, especially
the tables of dielectric and magnet wire.
High Voltage Generating Circuits
Things you can do with high voltage:
Electrophotographs Kirlian-like, uses thermal fax paper
Other information and tables:
Flyback types to look for
Transformers to look for
Dielectric table of common and not so common materials
Magnet wire table
Spark length voltage measurements.
of High Voltage Technique at the Universities
of Kosice covers High-Voltage technique, degradation of High-Voltage
elements, measuring methods in High-Voltage engineering, Electric
eliminators and separators, diagnostics of High-Voltage and ultra
High-Voltage equipment, computer networks and electronic equipment
High-Voltage Association web site is a resource of High-Voltage
Information for use within the electronic original equipment Market.
They have links
to numerous High Voltage supplies, as well as a Message
Papers related to High-Voltage engineering
written by faculty and staff members and students affiliated with
State University High-Voltage laboratory can be found here.
Applications Website provides a broad range of services related
to the field of electrostatics. The Electrostatic
Source Bookstore is particularly educational.
is a repository of scientific instruments, information, and technological
services relating to the early history of electricity, magnetism,
and atomic physics. They also offer a comprehensive selection of reprints
of classical masterworks on topics related to the construction and
use of early electrical devices.
While you're probably not
going to be building a High-Voltage
Electron Microscope Laboratory in your garage or basement, it
is a interesting mix of technologies.
has some of the most detailed pictures of fusors that I came across,
but be warned these pictures are big and slow to load. They have this
to say about High-Voltage fusor work:
In the presence of the proper
atmosphere and at high enough voltages, the Fusor is capable of actually
doing fusion. It was invented by Philo T. Farnsworth, inventor of
the television, in the 1960's. Today his research is being rekindled
for many reasons. One application currently being utilized is that
of neutron generation. Massive accelerators or radioactive material
has always been needed for the production of neutrons. However, similar
Fusor systems being studied are currently capable of over 10^9 neutrons/second
and are small enough to be easily transported. This technique of doing
fusion is called Inertial Electrostatic Confinement (IEC). It eliminates
the need for massive superconducting magnets and costly facilities
for doing simple fusion research. Perhaps one day this method will
lead to a better than break-even fusion process for nuclear power.
In this space, visitors are invited to
post any comments, questions, or skeptical observations about Philo
T. Farnsworth's contributions to the field of Nuclear Fusion research.
Pool has information on Philo T. Farnsworth, such as his patents,
including ion pumps, and his Nuclear Fusion Plasma devices. Bert has
among his High Voltage construction projects: "Powerful UV Laser Plans:
A pulsed cross-field molecular nitrogen laser."
More fusor related links can be found
at fus.x0r.com, pronounced fusor.com.
Because air itself can be a conductor,
many High Voltage experiments are done in vacuum.
Vacuum enthusiasts can find helpful,
practical information, including articles, announcements and more
links, on the Bell
Jar's home page. The site which is dedicated to the perfection
Also check out the bimonthly magazine
from the Institute of Physics Publishing. This magazine is
more oriented to the laboratory scientist.
J. Lesker Company deals in vacuum equipment.
Vacuum Products, Inc. has a useful Conversion
Factors For High Vacuum table.
Equipment New - Used - Rebuilt.
Plasma Sphere Secret
some natural High-Voltage
Sprites and Blue Jets http://www.cnn.com/NATURE/9904/05/
Atmospherics people have some interesting Lightning Information
on their site.
David Tweed's unofficial Circuit
shows that lightning has been a frequent topic in Circuit
has some beautiful pictures
American, Inc. has covered some interesting areas:
the Earth's Electricity by Shawn Carlson.
a Charge out of Rain by Shawn Carlson.
Associates, Inc. has a few simple-to-build Weather Circuits.
Detector (HTML) Detects radio pulses from approaching lightning
Detector (15k pdf) [12/95] Stick this out the window instead of
Barometer (HTML) This liquid barometer features a temperature-controlled
air chamber for excellent accuracy.
Monitor (59.4k pdf) [10/96]. Watch the electrical charges dance
in the clouds above during a thunderstorm!
The highest man-made voltage that I came
across in working on this Resource
Page seems to be the Pelletron�
charging chain used in NationalElectrostatics
Corporation devices. These are an improvement over the older Van
de Graff charging belts. The chain does not limit ultimate terminal
potential, and it is in use in electrostatic accelerators up to and
above 25 MV.
National Laboratory (ORNL) is one of the users of Pelletron charging
systems. Doing a search for "High Voltage" at ORNL yields over 300
related documents. As one example: Compact
Arrangement of High Voltage Grading Resistors with Surge Protection.
High-Voltage and Electromagnetic Compatibility Section at the
Eindhoven University of Technology (TUE)
in the Netherlands has some interesting abstracts like Pulsed
corona, a new technology to clean gas and liquid flows.
DoD SBIR Phase I Awards ---------- Agency: DARPA ----------
ALAMEDA APPLIED SCIENCES CORP.
6250 Bullard Drive
Oakland, CA 94611
PI: Rahul Prasad
Topic#: DARPA 95-008
Title: High Voltage, High Power Diamond
Solid-State Switch for Pulsed Power and Other Applications
Alameda Applied Sciences Corporation
(AASC) proposes a three phase effort with the ultimate goal of producing
a marketable diamond switch suitable for several pulsed power and
other applications in the defense arena. The presently used spark
gaps have several drawbacks including switch jitter, large and variable
inductance, lifetime and physical size. A low inductance solid-state
switch capable of switching 100 kV, 100 kA at a high repetition
rate would be desirable. The physical and electrical properties
of diamond make it uniquely suited to very high power electrical
switching applications. Electron beam controlled diamond switches
have been demonstrated at moderate (22 kV) voltages and current
densities >5 kA/cm2. Diamond, normally a good insulator, can carry
large currents when electron-hole pairs are created by the absorption
of an energetic electron beam. The objectives of the Phase I research
is to study the switching properties of diamond under high field
stress (1-10 MV/cm) to develop a design for a practical diamond
switch. The switch will be fabricated and validated in Phase II.
Commercialization is planned for Phase
III. Anticipated Benefits: DoD's pulsed power supplies for nuclear
weapons effects simulators and other applications including high
power lasers would benefit from the low inductance, low jitter,
fast rise-time, high-power diamond switch to be developed under
the proposed effort. Potential applications include switching systems
for the nation's power grid, high power accelerators, the More Electric
Aircraft, automobiles, and drilling rigs.
A Regulated 2400-VDC Power Supply:
Look at this great power-supply idea. SCRs on the transformer primary
adjust input duty cycle based on output voltage. Output voltage drops
about 3 V with a 1 kW Load! by A. R. (Al) Williams, VE6AXW,appeared
in the July/Aug 1999 issue of QEX.
is the ARRL's "Forum for Communications
Experimenters." Published bimonthly, it features technical articles,
columns, and other items of interest to radio amateurs and communications
Dr. Tesla probably deserves a Resource
Page of his own, but one cannot help run into his work when looking
for information on High Voltage. So until a Tesla Resource Page comes
to light, check out the Tesla
links member web sites together to form their sites into linked circles.
Their purpose: to allow more visitors to reach them quickly and easily.
To your benefit, you can locate related sites that don't always show
up in the Search Engines.
Some of the following applications of
High Voltage are, to say the least, odd. Even if you don't agree that
the application is possible in the realm of accepted physics today,
don't overlook the fact that the methods used for generating the required
High Voltage power supplies are still valid.
Jean-Louis Naudin in France builds some
of the coolest experiments I've ever seen. For example, his Poynting
Flow Thruster project (PFT motor mk1) runs on 24 uA of current
at 28 kVDC (672 mW). His Quest
of OVERUNITY and ElectroGravitic
Research sites have some interesting High-Voltage applications as
One cannot bring up ElectroGravitic Research
and not bring up The Thomas
Townsend Brown Site.
Brown, as a young student working under
Dr. Biefeld, discovered what has become known as the Biefeld-Brown
Effect in conventional physics. The tendency for a highly charged
(50 kVDC to 300 kVDC), high-K dielectric capacitor to move in the
direction of its positive plate. [If anyone has info on high-K dielectric
let me know.]
If anyone still has a doubt about electrostatic
type motors, you might find some of the items by Dr.
Oleg D. Jefimenko at the Department of Physics Morgantown, WV,
If none of those items get your head
banging then maybe some Electrostatic
ZONE** All aspects of High-Voltage photography
There is also a message
board that covers Kirlian Photography.
Space Craft Journal. A network of interactive research seeking
electrodynamic field propulsion techniques for space travel by investigating
electrostatics, electromagnetics, atomic physics, gravity, inertia,
energy, and aether concepts. To learn about NASA's visionary program
to promote research toward the development of alternatives to jet
propulsion, visit the Breakthrough Propulsion Physics pages:
Wonderful World of Science covers such items as:
Resonance Spectral Analysis with a home-built Cyclotron
Demonstrating Particle Mass Resonance with a home-built Cyclotron
Subatomic Particle Interactions with a 100 keV Linear Accelerator
Plasma: The Fourth State of Matter
Centre and Planetarium located in Wollongong in New South Wales,
Australia, describes the Van de Graaf Generator:
The Van de Graaf Generator has three
main sections, the base platform, the shaft, and the bulb. The shaft
has a belt running inside it in a continuous loop. The belt picks
up an electric charge at the base of the generator. This charge
is carried to the top where it is passed on to the bulb. The upper
section consists of a large metallic bulb, which becomes charged
with static electricity.
When a person stands on a sheet of
insulating plastic on the platform, the charge is passed on to them.
As a result, the person's hair, and sometimes shoelaces, stand on
end. Because the body has the same charge all over, in effect certain
parts of the body try to repel each other.
Page has step by step construction plans for your own Van
De Graaf Generator.
you would like to add any information on this topic or request a
specific topic to be covered, contact Bob
provides up-to-date information for engineers. Visit www.circuitcellar.com
for more information and additional articles.
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