Author Topic: Unusual polarized non-electrolytic energy discharge capacitor  (Read 1198 times)

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 207
  • Karma: +4/-0
  • Cedar Rapids, Iowa
    • View Profile
Unusual polarized non-electrolytic energy discharge capacitor
« on: December 13, 2019, 09:06:47 PM »
I saw this Aerovox energy discharge capacitor on E-Bay. What I find unusual about it is that it appears to have a preferred polarity. I seriously doubt that its electrolytic given its voltage rating so why does it have a preferred polarity? This seems to be contradictory to energy discharge applications which typically generate a damped sinusoid which is obviously AC. I couldn't find a data sheet for this series. Is anyone familiar with this capacitor technology?

https://www.ebay.com/itm/High-Voltage-Energy-Discharge-Capacitors-Aerovox-196uF-2200VDC/163973233399?hash=item262d90faf7:g:KbIAAOSwGrBd5wr9
« Last Edit: December 13, 2019, 11:02:10 PM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline AndreiRS

  • High Voltage Experimenter
  • **
  • Posts: 73
  • Karma: +0/-0
    • View Profile
Re: Unusual polarized non-electrolytic energy discharge capacitor
« Reply #1 on: December 13, 2019, 10:00:04 PM »
hmmm not really my area, but why not electrolytic..? Microwave oven capacitors are also made of these aluminum cans and have liquid inside and they don't leak. Much. :o ::)

Well when new at least. I have already seen some leaking, but they were also stuffed.

Offline klugesmith

  • High Voltage Engineer
  • ****
  • Posts: 218
  • Karma: +5/-0
    • View Profile
Re: Unusual polarized non-electrolytic energy discharge capacitor
« Reply #2 on: December 13, 2019, 10:31:03 PM »
Might there be an internal diode, to minimize voltage reversal in underdamped discharges?

I think the C and V values are in the ballpark for defibrillator applications,
where currents run around 100 A instead of many kA.

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 207
  • Karma: +4/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: Unusual polarized non-electrolytic energy discharge capacitor
« Reply #3 on: December 13, 2019, 10:46:20 PM »
hmmm not really my area, but why not electrolytic..? Microwave oven capacitors are also made of these aluminum cans and have liquid inside and they don't leak. Much. :o ::)

Well when new at least. I have already seen some leaking, but they were also stuffed.

Microwave oven capacitors are oil-filled but not electrolytic thus they have no polarity requirements and are perfectly suitable for high voltage AC operation although not energy discharge use. Electrolytic capacitors are filled with a liquid electrolyte, not oil.

Electrolytic capacitors are not recommended for energy discharge use primarily because they are not made for AC operation. They are also not constructed to dump hundreds of amps in tens of microseconds without damage. That being said I have seen them used in disc and ring launchers even though a damped sinusoid of multiple cycles definitely occurs. How long they will last in that role is undetermined but its not a recommended application. I have seen a comment stating that the capacitance degrades rapidly with use in this role thus indicating gradual damage.
« Last Edit: December 14, 2019, 08:58:17 PM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline T3sl4co1l

  • High Voltage Technician
  • ***
  • Posts: 147
  • Karma: +9/-0
    • View Profile
« Last Edit: December 14, 2019, 05:54:23 AM by T3sl4co1l »

Offline klugesmith

  • High Voltage Engineer
  • ****
  • Posts: 218
  • Karma: +5/-0
    • View Profile
Re: Unusual polarized non-electrolytic energy discharge capacitor
« Reply #5 on: December 14, 2019, 07:01:18 PM »
Good find.  Looks like "CD Aero, LLC" came from yet another corporate merger or acquisition.  So long, Aerovox.
And thank you, Tim, for sharing the paper about voltage reversal.

Maybe the wire pigtailed capacitor products are color coded for non-electrical reasons.
Marketing said it helps customers generate assembly and service drawings that are obviously unambiguous about which wire goes where.

Those caps ought to hold up much better than MWO capacitors in crushers/launchers, even if datasheet doesn't mention ESL or voltage reversal or kiloamperes.  You could put a respectable indentation in a beverage can using a capacitor easily lifted with two fingers.  By electromagnetic induction.  :)

-Rich

« Last Edit: December 14, 2019, 07:15:01 PM by klugesmith »

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 207
  • Karma: +4/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: Unusual polarized non-electrolytic energy discharge capacitor
« Reply #6 on: December 14, 2019, 09:04:49 PM »
Thanks for the voltage reversal paper Tim. I did already have that paper though. I found it very useful when I was designing my 6.5 KVA SGTC for predicting the life of my Maxwell 37667 capacitor bank. As I recall it came out to something like 70 years if I operated it for one hour per week! So these should last me for the rest of my life. This assumed that I started with new capacitors, which I didn't, but it sill indicated a very long life.
« Last Edit: December 14, 2019, 09:10:24 PM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline T3sl4co1l

  • High Voltage Technician
  • ***
  • Posts: 147
  • Karma: +9/-0
    • View Profile
Re: Unusual polarized non-electrolytic energy discharge capacitor
« Reply #7 on: December 15, 2019, 04:04:35 AM »
Yeah CDE bought AV a while ago... hmm, can't find a damn thing about when or how(!?), weird.

Presumably, you'll get better life by operating at lower voltage too, not that that's much help for a spark gap unit but you could still make a beefy SSTC that way I suppose.

Tim

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 207
  • Karma: +4/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: Unusual polarized non-electrolytic energy discharge capacitor
« Reply #8 on: December 15, 2019, 05:19:51 AM »
Yeah CDE bought AV a while ago... hmm, can't find a damn thing about when or how(!?), weird.

Presumably, you'll get better life by operating at lower voltage too, not that that's much help for a spark gap unit but you could still make a beefy SSTC that way I suppose.

Tim

My SGTC uses 6 Maxwell 37667 capacitors in a series-parallel arrangement with 3 strings in parallel and each string consisting of 2 capacitors in series. Since each capacitor is rated for 35 KV, this gives a maximum voltage rating of 70 KV for the capacitor bank. My peak charged capacitor bank voltage, according to JAVATC, is about 19 KV. This gives me a 3.7 peak voltage margin. This derating is where the majority of life extension comes from according to the paper.
« Last Edit: December 15, 2019, 05:21:54 AM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline T3sl4co1l

  • High Voltage Technician
  • ***
  • Posts: 147
  • Karma: +9/-0
    • View Profile
Re: Unusual polarized non-electrolytic energy discharge capacitor
« Reply #9 on: December 15, 2019, 07:44:41 PM »
Yeah that should last about forever... I meant the OP cap, since it's a rather large value and lower voltage.

Tim

Offline Mads Barnkob

  • Administrator
  • High Voltage Expert
  • *****
  • Posts: 1457
  • Karma: +24/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: Unusual polarized non-electrolytic energy discharge capacitor
« Reply #10 on: December 16, 2019, 10:18:51 AM »
Those capacitors remind me of those found in defibrillators, both in size and voltage (and opening the link from Uspring I can see that is spot on!)

Their lifetime calculations is based on such a single-use defibrillator is only made to hang on a wall for 5 years and then maybe give a jolt some 5-10 times, then it is thrown away, so that is its designed purpose. Keep that in mind.

Speaking of microwave oven capacitors, those are grossly overrated, maybe not as much anymore, but from what I found some years ago, here is a copy of its data/test "sheet": http://kaizerpowerelectronics.dk/pulse-power/333-joule-moc-capacitor-bank/   
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics
https://www.youtube.com/KaizerPowerElectronicsDk60/join - Please consider supporting the forum, websites and youtube channel!

High Voltage Forum

Re: Unusual polarized non-electrolytic energy discharge capacitor
« Reply #10 on: December 16, 2019, 10:18:51 AM »

 


* Recent Topics and Posts

post Single sided use of Xray XFMR
[Transformer (Ferrite Core)]
HighVoltageRulezz
August 10, 2020, 12:23:05 PM
post Re: XRay Tank- any ideas about what is inside
[Transformer (Ferrite Core)]
HighVoltageRulezz
August 10, 2020, 12:18:04 PM
post Re: making HV bobbins for ferrite transformers
[Transformer (Ferrite Core)]
johnf
August 10, 2020, 10:24:54 AM
post Re: making HV bobbins for ferrite transformers
[Transformer (Ferrite Core)]
davekni
August 10, 2020, 06:20:04 AM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
RoadReaper
August 10, 2020, 05:40:19 AM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
August 10, 2020, 02:07:26 AM
post making HV bobbins for ferrite transformers
[Transformer (Ferrite Core)]
Teravolt
August 10, 2020, 01:27:22 AM
post A Tesla coil and an antenna
[General Chat]
TheFreq
August 09, 2020, 09:02:32 PM
post Re: Fun with wireless power
[Solid State Tesla Coils (SSTC)]
Steve Ward
August 08, 2020, 10:22:04 PM
post Re: Fun with wireless power
[Solid State Tesla Coils (SSTC)]
T3sl4co1l
August 08, 2020, 03:36:40 PM
post Re: Fun with wireless power
[Solid State Tesla Coils (SSTC)]
acmq
August 08, 2020, 02:07:52 AM
post Re: LSI Nitrogen Laser tear-down and Homemade TEA Nitrogen and Dye Lasers
[Light, Lasers and Optics]
LesWright
August 06, 2020, 10:20:12 PM
post Re: LSI Nitrogen Laser tear-down and Homemade TEA Nitrogen and Dye Lasers
[Light, Lasers and Optics]
Weston
August 06, 2020, 08:45:59 PM
post Re: Cathodes in Compact Fluorescent Lamps
[Light, Lasers and Optics]
klugesmith
August 06, 2020, 05:41:04 PM
post Re: Dual MOT tesla coil
[Spark Gap Tesla Coils (SGTC)]
Jun
August 06, 2020, 03:53:58 PM
post LSI Nitrogen Laser tear-down and Homemade TEA Nitrogen and Dye Lasers
[Light, Lasers and Optics]
LesWright
August 06, 2020, 03:28:14 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
AstRii
August 06, 2020, 12:59:03 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Mads Barnkob
August 06, 2020, 10:51:43 AM
post Re: How much is the voltage used in Corona Discharge tubes for ozone Generation?
[Transformer (Ferrite Core)]
UB_Serpent
August 06, 2020, 08:40:57 AM
post Re: compact midi interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
TMaxElectronics
August 06, 2020, 03:22:38 AM
post Re: Dual MOT tesla coil
[Spark Gap Tesla Coils (SGTC)]
davekni
August 05, 2020, 11:48:55 PM
post Re: How much is the voltage used in Corona Discharge tubes for ozone Generation?
[Transformer (Ferrite Core)]
davekni
August 05, 2020, 11:37:13 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
AstRii
August 05, 2020, 08:01:11 PM
post Re: Fun with wireless power
[Solid State Tesla Coils (SSTC)]
Lightning On Demand
August 05, 2020, 06:34:08 PM
post Re: How much is the voltage used in Corona Discharge tubes for ozone Generation?
[Transformer (Ferrite Core)]
Uspring
August 05, 2020, 12:56:32 PM
post Re: Fun with wireless power
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
August 05, 2020, 12:55:52 PM
post Re: Bipolar high voltage multiplier project - more than 70cm hot arc discharge
[Voltage Multipliers]
Teravolt
August 04, 2020, 09:21:09 PM
post Re: How much is the voltage used in Corona Discharge tubes for ozone Generation?
[Transformer (Ferrite Core)]
johnf
August 04, 2020, 09:16:55 PM
post Re: Does anyone know how this site works.
[General Chat]
thedoc298
August 04, 2020, 05:53:03 PM
post Re: Does anyone know how this site works.
[General Chat]
thedoc298
August 04, 2020, 05:51:03 PM
post Re: Fun with wireless power
[Solid State Tesla Coils (SSTC)]
Lightning On Demand
August 04, 2020, 05:17:26 PM
post Re: Fun with wireless power
[Solid State Tesla Coils (SSTC)]
Max
August 04, 2020, 02:14:56 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
August 04, 2020, 02:08:07 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
futurist
August 04, 2020, 10:48:35 AM
post Re: How much is the voltage used in Corona Discharge tubes for ozone Generation?
[Transformer (Ferrite Core)]
UB_Serpent
August 04, 2020, 10:02:39 AM
post Re: Dual MOT tesla coil
[Spark Gap Tesla Coils (SGTC)]
Jun
August 04, 2020, 08:47:07 AM
post Re: Dual MOT tesla coil
[Spark Gap Tesla Coils (SGTC)]
Jun
August 04, 2020, 08:43:00 AM
post Re: Does anyone know how this site works.
[General Chat]
Mads Barnkob
August 04, 2020, 08:33:47 AM
post Re: Does anyone know how this site works.
[General Chat]
MRMILSTAR
August 04, 2020, 05:09:26 AM
post Does anyone know how this site works.
[General Chat]
thedoc298
August 04, 2020, 01:54:49 AM
post Fun with wireless power
[Solid State Tesla Coils (SSTC)]
Lightning On Demand
August 03, 2020, 11:55:41 PM
post Re: Dual MOT tesla coil
[Spark Gap Tesla Coils (SGTC)]
Teravolt
August 03, 2020, 09:17:40 PM
post Re: Dual MOT tesla coil
[Spark Gap Tesla Coils (SGTC)]
MRMILSTAR
August 03, 2020, 08:30:38 PM
post Re: Budget USB cameras
[High Speed Filming]
missoum0514
August 03, 2020, 06:56:08 PM
post Re: Dual MOT tesla coil
[Spark Gap Tesla Coils (SGTC)]
Jun
August 03, 2020, 05:23:15 PM
post Re: Is my xray transformer a ferrite core and how would I drive it?
[Transformer (Ferrite Core)]
nielsquake
August 03, 2020, 05:02:26 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
August 03, 2020, 04:31:04 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
futurist
August 03, 2020, 10:05:59 AM
post Re: Is my xray transformer a ferrite core and how would I drive it?
[Transformer (Ferrite Core)]
Mads Barnkob
August 03, 2020, 08:21:26 AM
post Re: Is my xray transformer a ferrite core and how would I drive it?
[Transformer (Ferrite Core)]
nielsquake
August 02, 2020, 11:45:38 PM

Sitemap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 
SimplePortal 2.3.6 © 2008-2014, SimplePortal