High voltage capacitors are passive electronic components that store charge and energy for use in high voltage applications. They consist of two conducting plates separated by an insulating material called the dielectric. Film capacitors are high voltage capacitors made out of plastic. There are two basic types:   Film-foil capacitors include one or more layers of a plastic film dielectric wound alternately with metal foil electrodes. Metallized film ...
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Q & A on High Voltage Capacitors

We asked our users for their input on High Voltage Capacitors. Here are the results of 56 users familiar with High Voltage Capacitors.

Who Took Our Poll? | Design Trends | Applications and Use | Features | Buying Advice

Who Took Our Poll?Top

Design TrendsTop

Q:
What new technologies are influencing high voltage capacitor design?
6 answers
Answers:
As to film/foil capacitors there has been slow, steady evolution in volume reduction. We hope that some of the monolithic (ceramic chip) capacitor technology that has allowed huge C x V / Volume increases in Low Voltage parts will someday enable compact, low ESR, ESL high voltage capacitors.
~David P, Engineering Consultant, West Dundee, IL
Leak current (the smaller the better) The power to withstand short circuit (a firing xenon flash tube behaves as a short-circuiting) Dimensions (the smaller the better)
~Arthur P, PEAC, Naaldwijk, The Netherlands
Need to improve volumetric efficiency in all capacitor types is the major driver.
~John B, Research & Development, Greenville, SC
High voltage capacitor for medium frequency range application and energy storage application.
~Goman Siu, Manufacturer, Hong Kong
Insulating fluid and size.
~Robert S, Manager, Power Test LAb, Horseheads, NY
Better insulators
~Juan C. N., Project Manager, Buenos Aires, Argentina

Q:
From your perspective, which companies are creating the most innovative high voltage capacitors?
8 answers
Answers:
Cornell Dubiler Several Japanese manufacturers
~Arthur P, PEAC, Naaldwijk, The Netherlands
SB Electronics, i.e. POWER RING; Bycap Inc. Excellent customer service and great optimization at minimum cost/size.
~David P, Engineering Consultant, West Dundee, IL
Really none, as 500v capacitors are being dropped by many manufacturers.
~Marketing/Sales, Paris, Canada
Hong Kong Film Capacitor (Shun Tai) Co Ltd
~Goman Siu, Manufacturer, Hong Kong
Hopefully my company, Kemet.
~John B, Research & Development, Greenville, SC
Panasonic are the best
~Architect/Builder/Contractor, Guaynabo, Puerto Rico
GA-ESI
~Juan C. N., Project Manager, Buenos Aires, Argentina
GE
~Robert S, Manager, Power Test LAb, Horseheads, NY

Applications and UseTop

Q:
What are some of the applications you have used high voltage capacitors for?
16 answers
Answers:
We have a 5 megajoule capacitor bank that we use as the power source for doing short circuit tests on vacuum interrupters. The individual capacitors are 15 kVDC, 75 microfarads. These units specially made power factor correction capacitors that do not have built in discharge resistors. As such they are fully reversible in voltage. We have other smaller capacitors rated to 120 kVDC that are used as TRV control capacitors.
~Robert S, Manager, Power Test LAb, Horseheads, NY
Applications in DC-DC power supplies, snubber capacitors in applications ranging from Medical to Industrial.
~John B, Research & Development, Greenville, SC
Photographic strobes, for use above and under water. I design them and build them on a small scale.
~Arthur P, PEAC, Naaldwijk, The Netherlands
>100MW pulse power generation, >100KV power supplies, magnetron pulseforming networks
~David P, Engineering Consultant, West Dundee, IL
High voltage high current discharge for high intensity magnetic fields.
~Roberto B, Engineer, Pesaro, Italy
Transcranial magnetic stimulation
~Research & Development, MONTREAL, Canada
X Ray Generators (diode capacitor multiplier).
~Juan C. N., Project Manager, Buenos Aires, Argentina
The capacitors I supply are specifically for vintage Kenwood and Yaesu Ham Radio transceivers from the 1970's-80's.
~Marketing/Sales, Paris, Canada
PFN Energy Storage RC Networks
~C S, Master Electronics Tech, Beverly, MA
Microwave transmitters fm tv
~Architect/Builder/Contractor, Guaynabo, Puerto Rico
High voltage power supplies
~Engineering, Design, HANDSCHUHEIM, France
Mass Spectrometers
~Engineering, Other, Manchester, United Kingdom
Tube amplifiers
~Maintenance/Facilities Management, Henderson, NV
Manufacturing
~Goman Siu, Manufacturer, Hong Kong
In medical
~Research & Development, Cairo, Egypt
ESWL
~Research & Development, Adana, Turkey

Q:
Please share with us any “non-standard” applications that high voltage capacitors have been used for.
4 answers
Answers:
Electrostatic discharge disruption of automotive electrical systems to terminate high-speed pursuit scenarios safely. Pulse power driving chemical reactions for hazardous material degradation/destruction.
~David P, Engineering Consultant, West Dundee, IL
Medium range converter and inverter.
~Goman Siu, Manufacturer, Hong Kong
Power factor correction on houses and factories.
~Architect/Builder/Contractor, Guaynabo, Puerto Rico
Short circuit testing.
~Robert S, Manager, Power Test LAb, Horseheads, NY

Q:
Do you know of any disastrous mistakes that occurred due to the incorrect usage of high voltage capacitors?
4 answers
Answers:
About 10 years ago a Voice of America transmitter caught fire and was totally destroyed by improper communication/understanding of capacitor RMS ripple current/frequency requirements. The loss was some $20 MILLION... During failure the capacitors in question overheated and ruptured, spraying hot mineral oil-based dielectric into the transmitter enclosure which was ignited by the ensuing power arcing of the disintegrating capacitor(s). The forced-air cooling of the transmitter supplied the oxygen to turn the transmitter into an inferno. In any such power application, the use of SILICONE, not MINERAL BASED capacitor dielectric fluid is strongly recommended; Silicone has far higher FLASH POINT and FIRE POINT than MINERAL, and a small fraction of the BTU VALUE!
~David P, Engineering Consultant, West Dundee, IL
We use our capacitors only up to 85% of the rated voltage and we still lose 20 or so each year out of a bank that has 576 units.
~Robert S, Manager, Power Test LAb, Horseheads, NY
Capacitor blew at high voltage, frequency and high temperature.
~Goman Siu, Manufacturer, Hong Kong
Yes, they explode if they can't withstand short-circuiting.
~Arthur P, PEAC, Naaldwijk, The Netherlands

FeaturesTop

Q:
What would your design or feature "wish list" be for this product?
8 answers
Answers:
For replacement applications the capacitors have to be form, fit and function identical to the ones we have in service.
~Robert S, Manager, Power Test LAb, Horseheads, NY
As small as possible At least 600 microfahrad At least 500 V Specially made for Photo flashes
~Arthur P, PEAC, Naaldwijk, The Netherlands
High capacity low resistance low inductance high current capability
~Roberto B, Engineer, Pesaro, Italy
Higher energy density, lower ESL/ESR, higher rep rates.
~David P, Engineering Consultant, West Dundee, IL
Higher capacitance, voltage and frequency range.
~Goman Siu, Manufacturer, Hong Kong
To find a wholesaler to buy from.
~Maintenance/Facilities Management, Henderson, NV
Minimal footprint.
~C S, Master Electronics Tech, Beverly, MA
Smaller sizes.
~Juan C. N., Project Manager, Buenos Aires, Argentina

Q:
Is there any advice you want to share with users to help them avoid common errors in selection or usage of high voltage capacitors?
4 answers
Answers:
The peak current, peak voltage, rms current/voltage, voltage reversal (in a pulse application), maximum temperature, cooling requirements due to capacitor dissipation in a power application, corona inception potential in a dry FF or metalized system, operating voltage vs. life, temperature vs. life, etc. etc. must be KNOWN AND PROPERLY SPECIFIED. Knowing the worst-case failure modes in high-energy circuits is also most important!
~David P, Engineering Consultant, West Dundee, IL
Be careful to discharge capacitors after use and use a shorting wire between terminals whenever capacitors are stored to prevent accidental charging.
~Robert S, Manager, Power Test LAb, Horseheads, NY
Capacitor quality is the highest concern, flame retardant and resistance to humidity is very important.
~Goman Siu, Manufacturer, Hong Kong
Assuming all capacitors rated to a given voltage have the same performance.
~John B, Research & Development, Greenville, SC

Buying AdviceTop

Q:
Do you have any advice for people relative to buying or using high voltage capacitors?
6 answers
Answers:
No, I design photo strobes and try to sell this design when ready. There is a big demand for reliable strobes amongst under water photographers.
~Arthur P, PEAC, Naaldwijk, The Netherlands
If you do not have sufficient experience in specifying the capacitor(s) for your particular application, SEEK COMPETENT HELP!!!
~David P, Engineering Consultant, West Dundee, IL
Understand the fitness for use prior to major purchasing activity.
~John B, Research & Development, Greenville, SC
Capacitor performance at frequency and high temperature condition.
~Goman Siu, Manufacturer, Hong Kong
Is very difficult finding capacitors with the needed characteristics.
~Roberto B, Engineer, Pesaro, Italy
Be specific about your application to potential vendors.
~Robert S, Manager, Power Test LAb, Horseheads, NY


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