Author Topic: Are bleeder resistors necessary if I can easily discharge my capacitor?  (Read 331 times)

Offline jpb133

  • High Voltage Enthusiast
  • *
  • Posts: 4
  • Karma: +0/-0
    • View Profile
I'm working on a mmc bank for my dual mot tesla coil, is it absolutely necessary to add bleeder resistors if I can easily discharge the capacitor? The terminals are close enough together that I can easily put a metal rod across them with the help of a well insulated pole. And wouldn't they discharge across the secondary coil of the transformer anyway? Can I simply short out the ends of the capacitor bank or must I discharge each capacitor individually? Thanks in advance for any information.

Offline profdc9

  • High Voltage Engineer
  • ****
  • Posts: 228
  • Karma: +11/-0
    • View Profile
I'm working on a mmc bank for my dual mot tesla coil, is it absolutely necessary to add bleeder resistors if I can easily discharge the capacitor? The terminals are close enough together that I can easily put a metal rod across them with the help of a well insulated pole. And wouldn't they discharge across the secondary coil of the transformer anyway? Can I simply short out the ends of the capacitor bank or must I discharge each capacitor individually? Thanks in advance for any information.

I made a dual mot tesla coil, and I discharged my capacitors with a rod across the safety spark gap.  However, if you forget to do this, and don't have bleeder resistors, the charge could easily kill someone.  Also, discharging the capacitors this way is hard on the capacitors, and occasionally even high quality Cornell-Dubilier capacitors have been known to explode if accidentally shorted.  I included twelve 33 megaohm resistors in series across each metal-oxide varistor as a bleeder.   I also had to include about 1000 pF of capacitance @ 20 kV for RF protection as well.

I have to say having built both a rotary spark gap MOT tesla coil and a DRSSTC, the DRSSTC is much more fun, and in some ways, easier to build.  Getting the rotary spark gap to work reliably was very hard.  The spark gap wheel is very hard to balance.  But I am happy to share details of how I put it together.  The schematic of my dual MOT tesla coil is attached.

Dan

Offline jpb133

  • High Voltage Enthusiast
  • *
  • Posts: 4
  • Karma: +0/-0
    • View Profile
Thanks for your help, it sounds like it would be worth it to add them in for safety and for the longevity of my capacitor bank. Can I use regular 10m ohm resistors either 1/2watt or 1 watt?

Offline MRMILSTAR

  • High Voltage Experimenter
  • **
  • Posts: 55
  • Karma: +2/-0
  • Cedar Rapids, Iowa
    • View Profile
All energy discharge capacitors have a maximum current rating. As an example, I use a bank of 6 Maxwell 37667 capacitors in series-parallel for my spark gap coil. Each capacitor has a maximum current rating of 25,000 amps. This sounds like a lot but if you discharge directly across the terminals you can easily exceed this possibly resulting in damage. I found this out the hard way. My first capacitor bank had the bus bars too close together. During operation I would get an occasional very loud bang caused by flash-over between the bus bars. After about 5 of these flash-overs, the case of one of my capacitors cracked under the mechanical stress and it started leaking oil. I then re-designed the array to move the bus bars further apart. I also use a bleed resistor across each capacitor.

High Voltage Forum


 


* Recent Topics and Posts

post Re: CM300 coil build questions
[Dual Resonant Solid State Tesla coils]
acobaugh
Today at 07:27:46 PM
post Re: CM300 coil build questions
[Dual Resonant Solid State Tesla coils]
acobaugh
Today at 06:56:20 PM
post Re: CM300 coil build questions
[Dual Resonant Solid State Tesla coils]
acobaugh
Today at 05:08:06 PM
post Re: CM300 coil build questions
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
Today at 01:35:58 PM
post Re: CM300 coil build questions
[Dual Resonant Solid State Tesla coils]
acobaugh
Today at 05:54:23 AM
post Re: Blast from the past!
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
klugesmith
Today at 05:05:55 AM
post Re: UD2.7 Gate Signals
[Dual Resonant Solid State Tesla coils]
coilinator
September 17, 2019, 08:24:59 PM
post Re: Blast from the past!
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
MRMILSTAR
September 17, 2019, 08:19:45 PM
post Re: Blast from the past!
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Mads Barnkob
September 17, 2019, 06:53:52 PM
post Blast from the past!
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
MRMILSTAR
September 17, 2019, 05:52:00 PM
post Re: CM300 coil build questions
[Dual Resonant Solid State Tesla coils]
acobaugh
September 17, 2019, 05:00:47 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
davekni
September 17, 2019, 06:48:38 AM
post Re: My second DRSSTC
[Dual Resonant Solid State Tesla coils]
erdal
September 16, 2019, 11:07:27 PM
post Re: 750W solar offgrid 24V/150Ah battery setup with Victron charger
[Electronic circuits]
johnf
September 16, 2019, 09:48:37 PM
post Re: adventures in homemade flyback bobbins.
[Transformer (ferrite core)]
AlexanderHun
September 16, 2019, 10:42:44 AM
post Re: Offgrid 48V solar to 24V battery setup
[Electronic circuits]
Mads Barnkob
September 16, 2019, 09:40:27 AM
post Re: My second DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
September 16, 2019, 09:28:43 AM
post Re: Large Ferrite Core with IGBT-Brick Driver
[Transformer (ferrite core)]
Mads Barnkob
September 16, 2019, 09:24:17 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
T3sl4co1l
September 16, 2019, 06:59:12 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
davekni
September 16, 2019, 04:18:26 AM
post Re: My second DRSSTC
[Dual Resonant Solid State Tesla coils]
davekni
September 16, 2019, 02:49:28 AM
post Re: Large Ferrite Core with IGBT-Brick Driver
[Transformer (ferrite core)]
davekni
September 16, 2019, 02:43:18 AM
post Re: Homemade HV transformer
[Transformer (ferrite core)]
davekni
September 16, 2019, 02:36:17 AM
post Re: adventures in homemade flyback bobbins.
[Transformer (ferrite core)]
davekni
September 16, 2019, 02:26:40 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
September 16, 2019, 01:50:19 AM
post Re: UD2.7 Gate Signals
[Dual Resonant Solid State Tesla coils]
coilinator
September 15, 2019, 08:22:47 PM
post Re: My second DRSSTC
[Dual Resonant Solid State Tesla coils]
erdal
September 15, 2019, 02:09:17 PM
post Re: Homemade HV transformer
[Transformer (ferrite core)]
AlexanderHun
September 15, 2019, 10:39:29 AM
post Re: Homemade HV transformer
[Transformer (ferrite core)]
ElectroXa
September 14, 2019, 07:01:28 PM
post Re: adventures in homemade flyback bobbins.
[Transformer (ferrite core)]
AlexanderHun
September 14, 2019, 06:59:13 PM
post Re: Homemade HV transformer
[Transformer (ferrite core)]
AlexanderHun
September 14, 2019, 06:43:15 PM
post Re: Homemade HV transformer
[Transformer (ferrite core)]
ritaismyconscience
September 14, 2019, 06:35:32 PM
post Homemade HV transformer
[Transformer (ferrite core)]
AlexanderHun
September 14, 2019, 05:05:00 PM
post Re: UD2.7 Gate Signals
[Dual Resonant Solid State Tesla coils]
profdc9
September 14, 2019, 04:50:10 PM
post Re: UD2.7 Gate Signals
[Dual Resonant Solid State Tesla coils]
coilinator
September 14, 2019, 08:42:55 AM
post Re: Transistors good for DRSSTC?
[Dual Resonant Solid State Tesla coils]
ritaismyconscience
September 13, 2019, 05:50:53 AM
post Re: Transistors good for DRSSTC?
[Dual Resonant Solid State Tesla coils]
Max
September 12, 2019, 12:47:03 PM
post Re: Transistors good for DRSSTC?
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
September 12, 2019, 11:07:39 AM
post Re: "karma", "applause/smite" button meaning and use
[General chatting]
Mads Barnkob
September 12, 2019, 11:01:05 AM
post Re: Transistors good for DRSSTC?
[Dual Resonant Solid State Tesla coils]
Hydron
September 12, 2019, 08:44:48 AM
post Transistors good for DRSSTC?
[Dual Resonant Solid State Tesla coils]
ritaismyconscience
September 12, 2019, 05:53:51 AM
post Re: "karma", "applause/smite" button meaning and use
[General chatting]
oneKone
September 12, 2019, 05:37:11 AM
post "karma", "applause/smite" button meaning and use
[General chatting]
MRMILSTAR
September 12, 2019, 05:07:24 AM
post Re: Why did 4HV die??
[General chatting]
oneKone
September 12, 2019, 04:50:24 AM
post Drsstc 4, I'm never stopping
[Dual Resonant Solid State Tesla coils]
oneKone
September 12, 2019, 02:36:00 AM
post Re: Why did 4HV die??
[General chatting]
Hydron
September 12, 2019, 12:34:10 AM
post Re: Why did 4HV die??
[General chatting]
MRMILSTAR
September 11, 2019, 09:29:40 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
MRMILSTAR
September 11, 2019, 09:00:31 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
coilinator
September 11, 2019, 07:54:30 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
freq_out
September 11, 2019, 05:40:14 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