Author Topic: Components of my 8.6 inch pig-powered SGTC: Ballast  (Read 1221 times)

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 212
  • Karma: +4/-0
  • Cedar Rapids, Iowa
    • View Profile
Components of my 8.6 inch pig-powered SGTC: Ballast
« on: August 30, 2019, 06:17:05 AM »
Here are some pictures of the ballast which I made to limit the current to my pole transformer. It is an adjustable air gap ballast. The maximum current is set by the thickness of the gap between the E and I sections. G10 or other hard plastic spacers are used to set the gap distance. The design specs are:

1. 240 volt operation
2. Maximum current can be set over the range of 4 amps through 40 amps without saturation
3. The center leg of the E sections is 3.75" x 3.75"
4. The E and I sections alone weigh 80 pounds
5. 73 turns of 8 AWG THHN stranded wire

I obtained the E and I sections from a dry-type 25 KVA 480/240/120 volt distribution transformer that weighed about 250 pounds. I individually de-interleaved a stack of E and I sections 12 inches high from the donor transformer. It was a lot of work. I used my lathe as a winding jig. Winding 8 AWG is extremely difficult. I had to stop each 1/4 turn to bend the wire cleanly around the corners of the bobbin. The finished ballast weighs about 100 pounds.

The ballast is mounted in the bottom of my control cabinet. It is very efficient. I have tested it up to 30 amps (the limit of my variac) and it runs completely cool to the touch.
« Last Edit: September 01, 2019, 05:19:49 AM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline klugesmith

  • High Voltage Engineer
  • ****
  • Posts: 252
  • Karma: +6/-0
    • View Profile
Re: Components of my 8.6 inch pig-powered SGTC: Ballast
« Reply #1 on: August 31, 2019, 02:29:35 AM »
Nice work there. 
I bet not your first exercise in coil-and-core transformer winding. 
A thing I've done a couple of times, but yours is bigger.  :-)

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 212
  • Karma: +4/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: Components of my 8.6 inch pig-powered SGTC: Ballast
« Reply #2 on: August 31, 2019, 02:38:39 AM »
Actually, it was my first attempt at core-and-coil. Though I will say that I studied the theory and building techniques thoroughly before I started and I had excellent tools. After having it done for over a year now, I can honestly say that I wouldn't change a thing about the design or construction, which is unusual for me. The hardest part was getting the E and I laminations. The hardest part of the construction was building a stiff and strong bobbin. Thanks for the generous compliment.
« Last Edit: August 31, 2019, 02:52:22 AM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline klugesmith

  • High Voltage Engineer
  • ****
  • Posts: 252
  • Karma: +6/-0
    • View Profile
Re: Components of my 8.6 inch pig-powered SGTC: Ballast
« Reply #3 on: August 31, 2019, 03:20:31 AM »
Are you familiar with the How It's Made video about pole transformers?
/>
I've never even touched a pole-type transformer myself.  Interesting that the one in video, perhaps a 50 kVA, has low voltage winding made from aluminum strip instead of wire.  One turn per layer.

Speaking of which ... When I measured the sheet resistance of Al alloy in beverage can bodies, it was between 50% and 100% higher than pure Al of the same thickness.  Have forgotten the actual value, and the alloy number found on Internet.  This really belongs in a general can-crushing thread.   With one helical cut, anybody can turn an empty can into a long, narrow strip to get a more easily measured resistance.  Anybody else here done that?

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 212
  • Karma: +4/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: Components of my 8.6 inch pig-powered SGTC: Ballast
« Reply #4 on: August 31, 2019, 04:34:41 AM »
I have not seen that video. Thanks for posting it. Interestingly, the donor distribution transformer that I delaminated had coils made only of thick aluminum strip about 0.5 inch x 0.125 inch tapped at a few points. There was no copper. I was able to extract the entire coil in one piece just by removing the tightening wedges. No cutting was required. I still have the coil. I have been trying to figure out something to do with it. Of coarse since it was a 480/240/120 volt transformer, the turns ratio was almost nothing (2 and 4). The coil had to carry big current though. It was a 25 KVA unit.
« Last Edit: August 31, 2019, 04:48:18 AM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline thedoc298

  • High Voltage Experimenter
  • **
  • Posts: 90
  • Karma: +1/-0
    • View Profile
Re: Components of my 8.6 inch pig-powered SGTC: Ballast
« Reply #5 on: September 07, 2019, 05:48:05 PM »
Would love to have that for my night stand. Great piece of work, I would be proud. Its like a big magnetic heart. Love it

High Voltage Forum

Re: Components of my 8.6 inch pig-powered SGTC: Ballast
« Reply #5 on: September 07, 2019, 05:48:05 PM »

 


* Recent Topics and Posts

post Re: DRSSTC Tuning for Music vs Big Sparks?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Uspring
Today at 05:50:56 PM
post Re: Easy to build Polyphonic MIDI Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
Today at 02:59:47 PM
post Re: VTTC on GU-81M
[Vacuum Tube Tesla Coils (VTTC)]
Continuum
Today at 12:18:10 PM
post Re: steam engine
[Capacitor Banks]
plasma
Today at 09:49:57 AM
post Re: steam engine
[Capacitor Banks]
Zipdox
Today at 09:18:53 AM
post Re: Am I Misunderstanding of DC Blocking Capacitors
[Solid State Tesla Coils (SSTC)]
Zipdox
Today at 09:13:12 AM
post Re: DRSSTC Tuning for Music vs Big Sparks?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
Today at 06:45:24 AM
post Re: DRSSTC driver
[General Chat]
Mads Barnkob
September 20, 2020, 08:37:58 PM
post Re: Current transformer for narrow spaces
[Laboratories, Equipment and Tools]
klugesmith
September 20, 2020, 05:31:25 PM
post Re: DRSSTC Tuning for Music vs Big Sparks?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GKnapp
September 20, 2020, 05:20:51 PM
post Re: Corona lockdown thread, tell about your situation
[General Chat]
Uspring
September 20, 2020, 03:46:15 PM
post Re: How do you all pronounce kluge or kludge?
[General Chat]
Uspring
September 20, 2020, 03:25:48 PM
post Re: DRSSTC Tuning for Music vs Big Sparks?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Uspring
September 20, 2020, 02:12:35 PM
post Re: DRSSTC Tuning for Music vs Big Sparks?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GKnapp
September 20, 2020, 02:02:34 PM
post Re: Corona lockdown thread, tell about your situation
[General Chat]
Hydron
September 20, 2020, 01:27:52 PM
post Re: Corona lockdown thread, tell about your situation
[General Chat]
Mads Barnkob
September 20, 2020, 11:58:14 AM
post Re: Corona lockdown thread, tell about your situation
[General Chat]
friday
September 20, 2020, 07:53:30 AM
post Re: How do you all pronounce kluge or kludge?
[General Chat]
johnf
September 20, 2020, 06:09:20 AM
post Re: How do you all pronounce kluge or kludge?
[General Chat]
MRMILSTAR
September 20, 2020, 05:58:46 AM
post Re: Am I Misunderstanding of DC Blocking Capacitors
[Solid State Tesla Coils (SSTC)]
T3sl4co1l
September 20, 2020, 04:40:21 AM
post Re: DRSSTC Tuning for Music vs Big Sparks?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
September 20, 2020, 02:22:28 AM
post Re: Cheapest source so far for step adjustable DC power for ZVS induction heaters
[Electronic Circuits]
davekni
September 20, 2020, 02:06:56 AM
post Re: Rogowski current probe
[Laboratories, Equipment and Tools]
Hydron
September 19, 2020, 11:34:01 PM
post How do you all pronounce kluge or kludge?
[General Chat]
klugesmith
September 19, 2020, 11:21:11 PM
post Re: Am I Misunderstanding of DC Blocking Capacitors
[Solid State Tesla Coils (SSTC)]
klugesmith
September 19, 2020, 10:13:44 PM
post Re: Fat wire for facility (a house)
[Laboratories, Equipment and Tools]
johnf
September 19, 2020, 09:40:56 PM
post steam engine
[Capacitor Banks]
plasma
September 19, 2020, 07:54:41 PM
post DRSSTC driver
[General Chat]
octopus1
September 19, 2020, 04:50:28 PM
post Re: Join Kaizer Power Electronics, Youtube channel now has memberships
[Crowdfunding]
Mads Barnkob
September 19, 2020, 04:50:23 PM
post Re: Cheapest source so far for step adjustable DC power for ZVS induction heaters
[Electronic Circuits]
petespaco
September 19, 2020, 03:27:57 PM
post DRSSTC Tuning for Music vs Big Sparks?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GKnapp
September 19, 2020, 01:41:14 PM
post Re: Fat wire for facility (a house)
[Laboratories, Equipment and Tools]
Mads Barnkob
September 19, 2020, 11:09:16 AM
post Am I Misunderstanding of DC Blocking Capacitors
[Solid State Tesla Coils (SSTC)]
werd
September 19, 2020, 08:13:55 AM
post Re: Cheapest source so far for step adjustable DC power for ZVS induction heaters
[Electronic Circuits]
davekni
September 19, 2020, 01:31:34 AM
post Cheapest source so far for step adjustable DC power for ZVS induction heaters
[Electronic Circuits]
petespaco
September 18, 2020, 11:58:14 PM
post Fat wire for facility (a house)
[Laboratories, Equipment and Tools]
klugesmith
September 18, 2020, 10:35:59 PM
post Re: SSTC or DRSSTC with GaN Transistors
[Solid State Tesla Coils (SSTC)]
Hydron
September 18, 2020, 05:29:24 PM
post Re: SSTC or DRSSTC with GaN Transistors
[Solid State Tesla Coils (SSTC)]
Zipdox
September 18, 2020, 03:52:08 PM
post Re: Rogowski current probe
[Laboratories, Equipment and Tools]
flyglas
September 18, 2020, 02:49:05 PM
post Re: IGBT Temperature
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hydron
September 18, 2020, 11:56:58 AM
post Re: IGBT Temperature
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Weston
September 18, 2020, 10:31:58 AM
post Re: Eensy weensy switchmode power supplies
[Electronic Circuits]
T3sl4co1l
September 18, 2020, 08:19:19 AM
post Re: Upper audio frequency interruption of HFSSTC
[Solid State Tesla Coils (SSTC)]
davekni
September 17, 2020, 11:18:25 PM
post Re: Rogowski current probe
[Laboratories, Equipment and Tools]
Hydron
September 17, 2020, 10:26:57 PM
post Re: SSTC or DRSSTC with GaN Transistors
[Solid State Tesla Coils (SSTC)]
Weston
September 17, 2020, 09:13:40 PM
post Re: Upper audio frequency interruption of HFSSTC
[Solid State Tesla Coils (SSTC)]
uzzors2k
September 17, 2020, 09:02:42 PM
post Re: Eensy weensy switchmode power supplies
[Electronic Circuits]
klugesmith
September 17, 2020, 07:46:08 PM
post Re: Rogowski current probe
[Laboratories, Equipment and Tools]
flyglas
September 17, 2020, 07:43:00 PM
post Re: SSTC or DRSSTC with GaN Transistors
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
September 17, 2020, 10:23:29 AM
post Re: Eensy weensy switchmode power supplies
[Electronic Circuits]
T3sl4co1l
September 17, 2020, 06:56:59 AM

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