Author Topic: My terry filter  (Read 523 times)

Offline thedoc298

  • High Voltage Experimenter
  • **
  • Posts: 79
  • Karma: +0/-0
    • View Profile
My terry filter
« on: October 11, 2019, 01:37:11 AM »
I have a couple of  30kv doorknob caps 500pf. With 15000 across them, that comes out to 3ma or 45watts that is prety hot. The fact that it is rated at 30kv does that mean it is good for the wattage. Never seen any with power rating on the ones on ebay.

Just did some testing and one good thing is its only 7500 across one cap to rf ground and after 5 min its just warm.

Also scored me a pig, only 7200 but it was free, so after get the current one going will switch over to pig power I just need Mrmlstar to roll me a big fat one, inductor.
« Last Edit: October 11, 2019, 02:11:13 AM by thedoc298 »

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 201
  • Karma: +4/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: My terry filter
« Reply #1 on: October 11, 2019, 05:13:51 AM »
Ha ha. Start looking for those big E and I sections.

I use a low pass RC filter (so-called Terry filter) on my pole pig although it probably isn't necessary. I had the parts so why not, it can't hurt. I use two Murata 500 pF doorknob caps each rated for 30 KV, one for each leg of the HV output. These capacitors work with no problem with my 14.4 KV transformer output. My coil draws 6.5 KVA.

The capacitor spec you are looking for is continuous RMS current handling capability. Unfortunately, this spec is not always supplied. It is related to the capacitor's internal resistance. Doorknob capacitors generally have a very low internal resistance so they can handle a fair amount of continuous current. The biggest problem with them is that as they heat up, the capacitance can change. While important for a tuned circuit, it is non-critical for the single-pole low pass filter which is used for transformer protection.
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline thedoc298

  • High Voltage Experimenter
  • **
  • Posts: 79
  • Karma: +0/-0
    • View Profile
Re: My terry filter
« Reply #2 on: October 11, 2019, 06:54:59 PM »
Ha ha. Start looking for those big E and I sections.

I use a low pass RC filter (so-called Terry filter) on my pole pig although it probably isn't necessary. I had the parts so why not, it can't hurt. I use two Murata 500 pF doorknob caps each rated for 30 KV, one for each leg of the HV output. These capacitors work with no problem with my 14.4 KV transformer output. My coil draws 6.5 KVA.

The capacitor spec you are looking for is continuous RMS current handling capability. Unfortunately, this spec is not always supplied. It is related to the capacitor's internal resistance. Doorknob capacitors generally have a very low internal resistance so they can handle a fair amount of continuous current. The biggest problem with them is that as they heat up, the capacitance can change. While important for a tuned circuit, it is non-critical for the single-pole low pass filter which is used for transformer protection.

I really appreciate all your help, just helps to have a second voice of someone that has done it before. I got that pig in my shop last night and could not believe how heavy they are. I use my welder for a ballast to test it out, still poped my 40 amp fuse after a bit.

High Voltage Forum

Re: My terry filter
« Reply #2 on: October 11, 2019, 06:54:59 PM »

 


* Recent Topics and Posts

post Measuring LED efficiency
[Light, Lasers and Optics]
TMaxElectronics
Today at 12:46:23 AM
post Re: Configuration of a half bridge.
[Electronic Circuits]
hammertone
July 07, 2020, 10:28:37 PM
post Re: Configuration of a half bridge.
[Electronic Circuits]
ElectroXa
July 07, 2020, 10:09:22 PM
post Re: Configuration of a half bridge.
[Electronic Circuits]
hammertone
July 07, 2020, 09:36:53 PM
post Re: Configuration of a half bridge.
[Electronic Circuits]
johnf
July 07, 2020, 09:20:12 PM
post Configuration of a half bridge.
[Electronic Circuits]
hammertone
July 07, 2020, 09:07:10 PM
post Re: Help needed: HV Driver circuit
[Transformer (Ferrite Core)]
T3sl4co1l
July 06, 2020, 10:29:17 PM
post Re: induction heater troubleshooting help
[Electronic Circuits]
petespaco
July 06, 2020, 06:53:26 PM
post Re: adventures in homemade flyback bobbins.
[Transformer (Ferrite Core)]
HighVoltageRulezz
July 06, 2020, 01:18:03 PM
post Re: Help needed: HV Driver circuit
[Transformer (Ferrite Core)]
HighVoltageRulezz
July 06, 2020, 01:05:32 PM
post Re: Help needed: HV Driver circuit
[Transformer (Ferrite Core)]
T3sl4co1l
July 06, 2020, 06:14:56 AM
post Re: Cathodes in Compact Fluorescent Lamps
[Light, Lasers and Optics]
klugesmith
July 05, 2020, 06:31:21 PM
post Re: Cathodes in Compact Fluorescent Lamps
[Light, Lasers and Optics]
HiVi
July 05, 2020, 12:30:02 PM
post Re: IGBTs keep dying (un-solved again)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
TMaxElectronics
July 04, 2020, 10:35:50 PM
post Re: IGBTs keep dying (un-solved again)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
July 04, 2020, 08:56:15 PM
post Re: Next Gen DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
TMaxElectronics
July 04, 2020, 04:37:32 PM
post Re: IGBTs keep dying (un-solved again)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
TMaxElectronics
July 04, 2020, 04:14:44 PM
post Dell PowerEdge M1000E Blade Server Teardown
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Mads Barnkob
July 04, 2020, 01:52:14 PM
post Help needed: HV Driver circuit
[Transformer (Ferrite Core)]
HighVoltageRulezz
July 04, 2020, 12:37:48 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
July 04, 2020, 12:17:47 AM
post Cathodes in Compact Fluorescent Lamps
[Light, Lasers and Optics]
klugesmith
July 03, 2020, 07:12:18 AM
post Re: What's needed to heat up 0.75 g of SiC (susceptor) mass until it turns dim-red??
[Radio Frequency]
klugesmith
July 03, 2020, 06:36:16 AM
post Re: IGBTs keep dying (un-solved again)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
July 03, 2020, 04:20:42 AM
post Re: "Slayer exciter" analysis
[Solid State Tesla Coils (SSTC)]
acmq
July 03, 2020, 03:01:56 AM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
AstRii
July 02, 2020, 11:17:48 PM
post Re: How to prevent secondary oxidation / Rust
[Dual Resonant Solid State Tesla coils (DRSSTC)]
MRMILSTAR
July 02, 2020, 11:09:25 PM
post Re: Differential probe testing setup
[Laboratories, Equipment and Tools]
TMaxElectronics
July 02, 2020, 10:57:02 PM
post Re: Differential probe testing setup
[Laboratories, Equipment and Tools]
Twospoons
July 02, 2020, 10:47:18 PM
post Re: How to prevent secondary oxidation / Rust
[Dual Resonant Solid State Tesla coils (DRSSTC)]
johnf
July 02, 2020, 09:03:20 PM
post Re: How to prevent secondary oxidation / Rust
[Dual Resonant Solid State Tesla coils (DRSSTC)]
DJthefirst
July 02, 2020, 08:01:03 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
July 02, 2020, 07:04:55 PM
post Re: How to prevent secondary oxidation / Rust
[Dual Resonant Solid State Tesla coils (DRSSTC)]
TMaxElectronics
July 02, 2020, 07:02:30 PM
post Re: IGBTs keep dying (solved for now)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
TMaxElectronics
July 02, 2020, 06:51:20 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
AstRii
July 02, 2020, 05:34:23 PM
post Re: How to prevent secondary oxidation / Rust
[Dual Resonant Solid State Tesla coils (DRSSTC)]
DJthefirst
July 02, 2020, 05:09:09 PM
post Re: How to prevent secondary oxidation / Rust
[Dual Resonant Solid State Tesla coils (DRSSTC)]
TMaxElectronics
July 02, 2020, 12:51:29 PM
post Differential probe testing setup
[Laboratories, Equipment and Tools]
TMaxElectronics
July 02, 2020, 12:20:18 PM
post Re: How to prevent secondary oxidation / Rust
[Dual Resonant Solid State Tesla coils (DRSSTC)]
MRMILSTAR
July 02, 2020, 05:30:41 AM
post How to prevent secondary oxidation / Rust
[Dual Resonant Solid State Tesla coils (DRSSTC)]
DJthefirst
July 02, 2020, 04:16:58 AM
post Re: induction heater troubleshooting help
[Electronic Circuits]
petespaco
July 02, 2020, 01:02:02 AM
post Re: What's needed to heat up 0.75 g of SiC (susceptor) mass until it turns dim-red??
[Radio Frequency]
T3sl4co1l
July 01, 2020, 06:54:30 AM
post Re: "Slayer exciter" analysis
[Solid State Tesla Coils (SSTC)]
T3sl4co1l
July 01, 2020, 06:25:30 AM
post Re: "Slayer exciter" analysis
[Solid State Tesla Coils (SSTC)]
acmq
July 01, 2020, 02:47:13 AM
post Re: A three-phase "tree phase" Tesla coil
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Steve Ward
July 01, 2020, 02:43:34 AM
post Re: induction heater troubleshooting help
[Electronic Circuits]
aes92000
July 01, 2020, 02:33:07 AM
post Re: induction heater troubleshooting help
[Electronic Circuits]
petespaco
July 01, 2020, 12:03:08 AM
post Re: induction heater troubleshooting help
[Electronic Circuits]
aes92000
June 30, 2020, 10:34:36 PM
post Re: E-Bay Marx generator
[Voltage Multipliers]
ritaismyconscience
June 30, 2020, 09:14:06 PM
post Re: What's needed to heat up 0.75 g of SiC (susceptor) mass until it turns dim-red??
[Radio Frequency]
ritaismyconscience
June 30, 2020, 09:05:32 PM
post Re: induction heater troubleshooting help
[Electronic Circuits]
ritaismyconscience
June 30, 2020, 09:01:55 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