Author Topic: Flat Secondary Coil on PCB?  (Read 1243 times)

Offline profdc9

  • High Voltage Engineer
  • ****
  • Posts: 234
  • Karma: +11/-0
    • View Profile
Flat Secondary Coil on PCB?
« on: May 01, 2019, 05:54:26 PM »
I was thinking about designing a small kit-based Tesla coil where rather than the seconary coil being a solenoid, it is a flat spiral.  Of course the secondary inductance goes down, but is there any reason this shouldn't work?  Flat spirals are already used for resonant power transfer applications (e.g. wireless charging and induction cookers).

The board I designed has (I calculate) about 1 mH of inductance.  It is about 150 turns of 0.13 mm wide traces separated by 0.15 mm.  This is the thinnest I could fit in the design rules of the process.

Anyways I was up late last night and drew up a PCB.  The hole in the middle is for a post to put the topload on sticking up from the PCB.  The hole on the edge is to connect the ground.  There is a six turn coil on the back that is used to sense the current in the secondary for feedback purposes.

I was thinking too that I could stack the boards to get more turns and place a thick HDPE insulator between them.    The center of each coil would be connected to the ground of the next in series, and these would be stacked as to be placed over the primary coil  so that the board would intersect  the magnetic field lines of the primary coil.

Here is what I drew up last night:



Any comments about this design?  I want to call it the "Conversation Piece" which would be a little tabletop SSTC coil.  It would be powered by 12-30 VAC.

Dan

Offline Phoenix

  • High Voltage Experimenter
  • **
  • Posts: 70
  • Karma: +1/-0
    • View Profile

Offline profdc9

  • High Voltage Engineer
  • ****
  • Posts: 234
  • Karma: +11/-0
    • View Profile
Re: Flat Secondary Coil on PCB?
« Reply #2 on: May 01, 2019, 07:34:33 PM »
You wouldn't happen to know of a video of it in use?  I am curious to see how they work.  I was thinking of adding a buck converter before the half/full bridge so that I could modulate the power with an audio signal.

Dan

Hello

I know that such tesla coils work, because they are sold commercially: https://highvoltageshop.com/epages/b73088c0-9f9a-4230-9ffc-4fd5c619abc4.sf/de_DE/?ObjectPath=/Shops/b73088c0-9f9a-4230-9ffc-4fd5c619abc4/Products/TESLA_MINI_v1.2_

In the description you can see the technical data of the coil, it has 120 turns: https://highvoltageshop.com/epages/b73088c0-9f9a-4230-9ffc-4fd5c619abc4.sf/de_DE/?ObjectPath=/Shops/b73088c0-9f9a-4230-9ffc-4fd5c619abc4/Products/TC12_flach

Greetings
Phoenix

Offline Phoenix

  • High Voltage Experimenter
  • **
  • Posts: 70
  • Karma: +1/-0
    • View Profile
Re: Flat Secondary Coil on PCB?
« Reply #3 on: May 01, 2019, 08:17:27 PM »
No, i do not have a video about this coil. But if you look at the image from the second link, you can see that the primary is on the same PCB as the secondary. There are 2 bigger traces after the secondary coil.

The description says that this is a class E SSTC. I think you could use any normal Audio PLL Class E SSTC schematic and simply hook this coil up instead of a classical resonator: http://uzzors2k.4hv.org/projectfiles/classesstc1/classE_SSTC.GIF

Maybe you need to adjust some component values according to your resonant frequency, but the basic principle is the same.

Greetings
Phoenix

Offline oneKone

  • High Voltage Engineer
  • ****
  • Posts: 289
  • Karma: +8/-0
    • View Profile
Re: Flat Secondary Coil on PCB?
« Reply #4 on: May 02, 2019, 01:24:07 AM »
The only thing I can offer here is another reference. This coil is still early days but it is a drsstc.
https://hackaday.io/project/165112-pcbtc-gan-edition

Offline profdc9

  • High Voltage Engineer
  • ****
  • Posts: 234
  • Karma: +11/-0
    • View Profile
Re: Flat Secondary Coil on PCB?
« Reply #5 on: May 02, 2019, 02:06:27 AM »
The only thing I can offer here is another reference. This coil is still early days but it is a drsstc.
https://hackaday.io/project/165112-pcbtc-gan-edition

Thanks for the link.  That looks like an awesome project.

Thanks to you both for the info.  It gives food for thought.  I didn't think I was the only one who thought of this, but obviously there's been some movement here. :)

I was thinking of keeping the primary and secondary on separate PCBs so I could stack several secondaries to get more turns, and also I put the sense coil on the other side of the secondary board so that it there is less of a chance of having a coil strike damage the circuity (if it is possible to have a streamer that long).

dan

Offline Mads Barnkob

  • Administrator
  • High Voltage Expert
  • *****
  • Posts: 1263
  • Karma: +18/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: Flat Secondary Coil on PCB?
« Reply #6 on: June 04, 2019, 09:04:46 AM »
You could stack multiply PCBs as its done with planar transformers where the PCB are connected with VIA and the primary/secondary are interleaved for highest possible coupling.

I know this might not work as well with a high voltage output like this, but at least it is a common used practise to make these electronic layer cakes.
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline nick

  • High Voltage Enthusiast
  • *
  • Posts: 12
  • Karma: +0/-0
    • View Profile
Re: Flat Secondary Coil on PCB?
« Reply #7 on: November 22, 2019, 12:04:52 PM »
I coincidentally came across the project below today while looking for something else. Your post immediately rang a bell. Maybe some of his info is helpful.

http://www.megavolts.nl/en/projects/tesla-coils/201-pcb-spiral-teslacoil-en

Offline klugesmith

  • High Voltage Technician
  • ***
  • Posts: 131
  • Karma: +5/-0
    • View Profile
Re: Flat Secondary Coil on PCB?
« Reply #8 on: November 22, 2019, 06:59:51 PM »
The board I designed has (I calculate) about 1 mH of inductance.  It is about 150 turns of 0.13 mm wide traces separated by 0.15 mm.  This is the thinnest I could fit in the design rules of the process.
Dan, what's your estimate of the DC resistance, and resulting effect on Q of primary circuit?
A simple rule of thumb: Sheet resistance is about 1/2 milliohm per square for 1 ounce copper foil (about 35 um thick).  The resistance of your fine-pitch spiral can be a good indicator of actual trace width after etching.

[edit] Oops, you were proposing the flat spiral coil for _secondary_ TC winding.  Point still stands:  Resistive damping is strong unless L/R (in seconds) is large compared to period of oscillation.
« Last Edit: November 23, 2019, 02:50:35 AM by klugesmith »

High Voltage Forum

Re: Flat Secondary Coil on PCB?
« Reply #8 on: November 22, 2019, 06:59:51 PM »

 


* Recent Topics and Posts

post Re: DIY 250W LED Flood Light for High Speed Filming
[Light, Lasers and Optics]
Mads Barnkob
February 23, 2020, 09:04:34 PM
post HP T620 thin to plus conversion....
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
spacecabbie
February 23, 2020, 02:03:15 PM
post Re: GDT keeps on killing IGBTs
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ritaismyconscience
February 23, 2020, 05:43:17 AM
post Re: 230 volts spark gap
[Spark Gap Tesla Coils (SGTC)]
klugesmith
February 23, 2020, 04:07:51 AM
post Finding accelerometer location inside a phone
[Smart Phones]
haversin
February 22, 2020, 07:23:28 PM
post Re: GDT keeps on killing IGBTs
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dj.cosmo.esq
February 22, 2020, 07:41:18 AM
post Re: GDT keeps on killing IGBTs
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ritaismyconscience
February 22, 2020, 06:49:22 AM
post Re: GDT keeps on killing IGBTs
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
February 22, 2020, 03:39:10 AM
post Re: 230 volts spark gap
[Spark Gap Tesla Coils (SGTC)]
Quentief
February 22, 2020, 02:32:55 AM
post Re: 230 volts spark gap
[Spark Gap Tesla Coils (SGTC)]
klugesmith
February 22, 2020, 02:10:34 AM
post Re: 230 volts spark gap
[Spark Gap Tesla Coils (SGTC)]
Quentief
February 22, 2020, 01:27:41 AM
post Re: GDT keeps on killing IGBTs
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hydron
February 21, 2020, 08:00:10 PM
post Re: GDT keeps on killing IGBTs
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
February 21, 2020, 02:44:44 PM
post Re: 230 volts spark gap
[Spark Gap Tesla Coils (SGTC)]
klugesmith
February 21, 2020, 07:21:13 AM
post Re: GDT keeps on killing IGBTs
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ritaismyconscience
February 21, 2020, 06:11:32 AM
post Re: GDT keeps on killing IGBTs
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
February 21, 2020, 04:42:34 AM
post Re: 230 volts spark gap
[Spark Gap Tesla Coils (SGTC)]
davekni
February 21, 2020, 04:37:53 AM
post Re: UV-cured cyanoacrylate glues?
[Light, Lasers and Optics]
Twospoons
February 21, 2020, 04:28:33 AM
post Re: UV-cured cyanoacrylate glues?
[Light, Lasers and Optics]
klugesmith
February 21, 2020, 04:21:31 AM
post GDT keeps on killing IGBTs
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ritaismyconscience
February 21, 2020, 02:41:03 AM
post Re: 230 volts spark gap
[Spark Gap Tesla Coils (SGTC)]
Quentief
February 21, 2020, 12:28:20 AM
post Re: UV-cured cyanoacrylate glues?
[Light, Lasers and Optics]
Twospoons
February 20, 2020, 09:45:21 PM
post Re: UV-cured cyanoacrylate glues?
[Light, Lasers and Optics]
klugesmith
February 20, 2020, 07:28:01 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
Uspring
February 20, 2020, 02:06:26 PM
post Re: UV-cured cyanoacrylate glues?
[Light, Lasers and Optics]
shrad
February 20, 2020, 10:38:01 AM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
davekni
February 20, 2020, 05:14:43 AM
post Re: Is this flyback OK for my Plasma ball ?
[Transformer (Ferrite Core)]
davekni
February 20, 2020, 05:04:50 AM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
klugesmith
February 20, 2020, 04:47:41 AM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
Peregrine
February 19, 2020, 07:29:23 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
Peregrine
February 19, 2020, 06:47:55 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
Peregrine
February 19, 2020, 06:45:23 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
Teravolt
February 19, 2020, 06:41:42 PM
post Re: Is this flyback OK for my Plasma ball ?
[Transformer (Ferrite Core)]
John123
February 19, 2020, 06:10:34 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
MRMILSTAR
February 19, 2020, 05:52:20 PM
post Re: Is this flyback OK for my Plasma ball ?
[Transformer (Ferrite Core)]
ElectroXa
February 19, 2020, 05:05:50 PM
post Re: Is this flyback OK for my Plasma ball ?
[Transformer (Ferrite Core)]
John123
February 19, 2020, 04:11:22 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
Uspring
February 19, 2020, 02:03:12 PM
post Is this flyback OK for my Plasma ball ?
[Transformer (Ferrite Core)]
warmania
February 19, 2020, 11:24:58 AM
post Re: HP T620 Thin Client - PSU Hack And Windows PC Modification
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
latethannever
February 19, 2020, 11:00:15 AM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
rikkitikkitavi
February 19, 2020, 10:43:13 AM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
Peregrine
February 19, 2020, 06:54:14 AM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
klugesmith
February 19, 2020, 06:51:52 AM
post Re: 230 volts spark gap
[Spark Gap Tesla Coils (SGTC)]
davekni
February 19, 2020, 03:53:13 AM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
ElectroXa
February 18, 2020, 09:44:25 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
MRMILSTAR
February 18, 2020, 09:34:06 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
Peregrine
February 18, 2020, 08:27:31 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
Weston
February 18, 2020, 07:55:14 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
Peregrine
February 18, 2020, 07:32:04 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
klugesmith
February 18, 2020, 05:58:39 PM
post Re: Help!Capacitor that burns out after a while!
[Voltage Multipliers]
MRMILSTAR
February 18, 2020, 05:16:55 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