Author Topic: Help Tuning Class E Tesla Coil  (Read 1062 times)

Offline Benjamin_collier

  • High Voltage Enthusiast
  • *
  • Posts: 5
  • Karma: +0/-0
    • View Profile
Help Tuning Class E Tesla Coil
« on: April 22, 2023, 06:37:38 AM »
I've been working on this class E Tesla coil based on Steve Ward's design..
It works decently considering im only giving it 15V right now as I want to tune it before I increase the voltage so I can avoid mosfet and driver casualties. The issue is I am having a hard time tuning it properly. I am trying to follow the advice on steve wards website and get nice waveforms  (yellow = gate voltage purple = Vds)..

From following the advice on the website it seems I need more primary inductance however when I do that the performance is much worse; I have settled on around 2.5 turns for the primary.

Here is my build.

I am aware that the string of capacitors and the breadboard are likely affecting my performance due to large parasitics but I want to dial it in before I put it on a protoboard or a PCB.

Any advice would be appreciated.

Offline davekni

  • Executive Board Member
  • *******
  • Posts: 2826
  • Karma: +134/-2
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Help Tuning Class E Tesla Coil
« Reply #1 on: April 23, 2023, 06:29:17 AM »
Quote
I am aware that the string of capacitors and the breadboard are likely affecting my performance due to large parasitics but I want to dial it in before I put it on a protoboard or a PCB.
Unfortunately, I believe parasitics are causing too much trouble to allow reasonable tuning.  With a couple changes, you can likely make a breadboard build that works well enough for tuning.

First, for all power circuits such as Tesla coils, it is important to keep high-current connections separate from control signals, including FET gate drive.  In particular, primary B+ lead needs to go to B+ bypass caps away from control circuitry, directly at FET.  In other words, FET drain to primary winding to bypass caps to FET source needs to be wired separately from FET gate and control circuitry.  A separate wire from FET source is needed to connect to control electronics.  Best to twist that source wire with gate wire (twisted pair) as Steve did in his build.

Second, specific to class-E, resonant cap(s) need to have low inductance and be soldered directly to FET source and drain.  Again, see Steve Ward's build page and image.  Series-connected caps are not good.  Inductance will be too high.  Parallel is OK.  I can't quite tell in Steve's picture if there is one cap or two in parallel, one under the other.  Either way, they are soldered directly to the FET with minimal lead length.  (Reason for this is that class-E circuits have very rapid transfer of current from FET to resonant capacitor(s) as FET is turned off.  This becomes high dI/dt, so creates high voltage across any parasitic inductance between FET and caps.)

After you make above changes, yes, likely will need either higher primary coil inductance or higher capacitance.

Couple less-important thoughts.  Vgs scope capture shows ~7.5V if I'm interpreting correctly.  Is your 12V supply sagging to 8V or so?  Or perhaps it is an issue with primary coil current returning through control electronics causing low Vgs.  If so, above changes will fix that.  Also, coupling between primary and secondary coils looks rather low based on your image.  You may want to play with JavaTC.  That and an analog simulation program would allow tuning by computer simulation as a pre-step to actual testing.  (My favorite free analog simulator is LTSpice.  There are others.)

Good luck with your project!  And welcome to the forum.
David Knierim

Offline Benjamin_collier

  • High Voltage Enthusiast
  • *
  • Posts: 5
  • Karma: +0/-0
    • View Profile
Re: Help Tuning Class E Tesla Coil
« Reply #2 on: May 08, 2023, 04:34:30 AM »
Quote
I am aware that the string of capacitors and the breadboard are likely affecting my performance due to large parasitics but I want to dial it in before I put it on a protoboard or a PCB.
Unfortunately, I believe parasitics are causing too much trouble to allow reasonable tuning.  With a couple changes, you can likely make a breadboard build that works well enough for tuning.

First, for all power circuits such as Tesla coils, it is important to keep high-current connections separate from control signals, including FET gate drive.  In particular, primary B+ lead needs to go to B+ bypass caps away from control circuitry, directly at FET.  In other words, FET drain to primary winding to bypass caps to FET source needs to be wired separately from FET gate and control circuitry.  A separate wire from FET source is needed to connect to control electronics.  Best to twist that source wire with gate wire (twisted pair) as Steve did in his build.



I am not sure what you mean by B+ and what you mean by "wired seperatley". Maybe you could provide a drawing to clarify what you mean? Thanks for the feedback, I am currently working on putting it all on a protoboard but I have gone through several mosfet drivers. I assume its from transients in my supply and ground so perhaps I need better bypass capacitors.

Offline davekni

  • Executive Board Member
  • *******
  • Posts: 2826
  • Karma: +134/-2
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Help Tuning Class E Tesla Coil
« Reply #3 on: May 08, 2023, 06:18:52 AM »
Quote
I am not sure what you mean by B+ and what you mean by "wired seperatley".
"B+" means the signal (supply voltage) labeled "B+" in the schematic you posted.  I used the same name to match what is in your first post.

I don't have time to redraw the schematic.  But take the upper left power supply section, T1 through C3, and move that to the right of Q1.  Then make the physical connections match the schematic.  Wire from supply section (B+ and Ground) to L1 and source of Q1.  Then wire source and gate of Q1 to driver section (U3 and R5).  Only connection that needs to bypass FET is signal +12V.  (Would be best to have an inductor or at least ferrite bead in series with +12V between supply section and driver section since "ground" potential will be a little different due to wire inductance.  Probably not critical, however.)  Will also work best if C1, C2, and C9 are at least somewhat close to Q1 and L1 (primary coil) lead wires are twisted as they run from Q1 drain and B+ to coil.
David Knierim

High Voltage Forum

Re: Help Tuning Class E Tesla Coil
« Reply #3 on: May 08, 2023, 06:18:52 AM »

 


* Recent Topics and Posts

post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Jj
Today at 03:09:41 AM
post Re: Are TVS diodes necessary for full bridge?
[Solid State Tesla Coils (SSTC)]
Simranjit
Today at 01:53:07 AM
post Re: UD+ debugging (randomly skipping pulses)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
Today at 01:07:30 AM
post Re: UD+ debugging (randomly skipping pulses)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
AstRii
Today at 12:45:22 AM
post Re: UD+ debugging (randomly skipping pulses)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 14, 2024, 10:41:03 PM
post UD+ debugging (randomly skipping pulses)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
AstRii
June 14, 2024, 10:20:00 PM
post Re: Are TVS diodes necessary for full bridge?
[Solid State Tesla Coils (SSTC)]
davekni
June 14, 2024, 09:47:48 PM
post Fronius IG Plus 2LT-2 6kW Solar Inverter Teardown
[Electronic Circuits]
Mads Barnkob
June 14, 2024, 09:40:33 PM
post Re: Are TVS diodes necessary for full bridge?
[Solid State Tesla Coils (SSTC)]
Simranjit
June 14, 2024, 07:44:12 AM
post Re: Are TVS diodes necessary for full bridge?
[Solid State Tesla Coils (SSTC)]
davekni
June 14, 2024, 05:21:55 AM
post Re: Are TVS diodes necessary for full bridge?
[Solid State Tesla Coils (SSTC)]
Simranjit
June 14, 2024, 03:24:43 AM
post Re: Are TVS diodes necessary for full bridge?
[Solid State Tesla Coils (SSTC)]
davekni
June 14, 2024, 03:13:44 AM
post Re: Are TVS diodes necessary for full bridge?
[Solid State Tesla Coils (SSTC)]
Simranjit
June 14, 2024, 02:27:06 AM
post Re: Are TVS diodes necessary for full bridge?
[Solid State Tesla Coils (SSTC)]
davekni
June 14, 2024, 01:56:58 AM
post Are TVS diodes necessary for full bridge?
[Solid State Tesla Coils (SSTC)]
Simranjit
June 13, 2024, 11:21:46 PM
post Re: Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
Teslaventje
June 13, 2024, 08:50:56 PM
post Re: Steve Ward's DRSSTC Interrupter stops working when adjusting pulse width
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
June 13, 2024, 07:43:37 PM
post Re: Steve Ward's DRSSTC Interrupter stops working when adjusting pulse width
[Dual Resonant Solid State Tesla coils (DRSSTC)]
petespaco
June 13, 2024, 04:52:08 PM
post Re: Turning SSTC into DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
June 13, 2024, 02:14:17 AM
post Re: Turning SSTC into DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 12, 2024, 11:04:57 PM
post Turning SSTC into DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
June 12, 2024, 10:23:08 PM
post Re: UD2.7C constantly in OCP despite having signal
[Dual Resonant Solid State Tesla coils (DRSSTC)]
verliebt_in_neukölln17
June 12, 2024, 08:41:06 PM
post Re: UD2.7C constantly in OCP despite having signal
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 12, 2024, 07:53:31 PM
post Re: Van de Graaf Voltage measurement with voltage sensor and voltage divider
[Static Electricity]
haversin
June 12, 2024, 06:57:13 PM
post UD2.7C constantly in OCP despite having signal
[Dual Resonant Solid State Tesla coils (DRSSTC)]
verliebt_in_neukölln17
June 12, 2024, 06:54:49 PM
post Re: Van de Graaf Voltage measurement with voltage sensor and voltage divider
[Static Electricity]
Mads Barnkob
June 12, 2024, 03:47:28 PM
post Van de Graaf Voltage measurement with voltage sensor and voltage divider
[Static Electricity]
vK
June 12, 2024, 03:42:18 AM
post Re: Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
davekni
June 12, 2024, 03:32:22 AM
post Re: Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
Teslaventje
June 11, 2024, 11:05:49 PM
post Re: Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
June 11, 2024, 05:36:46 AM
post Re: Sling Psychrometer
[Laboratories, Equipment and Tools]
Twospoons
June 11, 2024, 12:29:31 AM
post Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
Teslaventje
June 10, 2024, 11:05:55 PM
post Re: Syntherrupter - A Feature-rich, Polyphonic Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
June 10, 2024, 10:57:51 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 10, 2024, 08:08:04 PM
post Re: Plasma Torid - Class E Self Resonant Dual/Stereo - Plasma Torid Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
June 10, 2024, 06:04:09 PM
post Sling Psychrometer
[Laboratories, Equipment and Tools]
klugesmith
June 10, 2024, 04:43:59 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 10, 2024, 03:35:28 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Jj
June 10, 2024, 01:36:41 PM
post Re: Is a 60UF 800VDC Dawncap good for an induction heater?
[General Chat]
Anders Mikkelsen
June 09, 2024, 05:44:29 PM
post Is a 60UF 800VDC Dawncap good for an induction heater?
[General Chat]
yourboi
June 09, 2024, 03:31:30 PM
post Re: Steve Ward's DRSSTC Interrupter stops working when adjusting pulse width
[Dual Resonant Solid State Tesla coils (DRSSTC)]
NyaaX_X
June 09, 2024, 01:34:49 PM
post Steve Ward's DRSSTC Interrupter stops working when adjusting pulse width
[Dual Resonant Solid State Tesla coils (DRSSTC)]
verliebt_in_neukölln17
June 09, 2024, 01:56:51 AM
post Re: Return of Electronics Flea Market in "Silicon Valley"
[Sell / Buy / Trade]
klugesmith
June 08, 2024, 06:06:25 AM
post Re: Coulometric hourmeters
[Laboratories, Equipment and Tools]
klugesmith
June 08, 2024, 05:38:14 AM
post Interrupter for SSTC
[Beginners]
Simranjit
June 08, 2024, 12:47:47 AM
post Re: Adding capacitor to primary in SSTC
[Solid State Tesla Coils (SSTC)]
Michelle_
June 07, 2024, 03:59:57 PM
post Re: Adding capacitor to primary in SSTC
[Solid State Tesla Coils (SSTC)]
davekni
June 07, 2024, 06:42:26 AM
post Re: Space-X Starship test this week
[Science, Research and News In Other Fields Than Electronics]
MRMILSTAR
June 07, 2024, 05:08:00 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
davekni
June 07, 2024, 03:16:31 AM
post Re: Space-X Starship test this week
[Science, Research and News In Other Fields Than Electronics]
klugesmith
June 06, 2024, 11:37:20 PM
post Adding capacitor to primary in SSTC
[Solid State Tesla Coils (SSTC)]
Simranjit
June 06, 2024, 11:20:23 PM
post Re: Plasma Torid - Class E Self Resonant Dual/Stereo - Plasma Torid Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alan sailer
June 06, 2024, 10:54:48 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
ZakW
June 06, 2024, 05:17:02 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 06, 2024, 04:50:00 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
davekni
June 06, 2024, 04:00:52 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
ZakW
June 06, 2024, 01:43:41 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 05, 2024, 11:11:17 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Michelle_
June 05, 2024, 10:18:57 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 05, 2024, 10:13:03 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
ZakW
June 05, 2024, 09:29:18 PM
post Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 05, 2024, 08:46:53 PM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Twospoons
June 05, 2024, 07:04:45 AM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Domo
June 05, 2024, 04:58:35 AM
post Re: Pearson current monitor model 1330 teardown (100kA)
[Laboratories, Equipment and Tools]
klugesmith
June 05, 2024, 01:42:04 AM
post Re: Coulometric hourmeters
[Laboratories, Equipment and Tools]
klugesmith
June 04, 2024, 10:31:58 PM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
pete_dl
June 04, 2024, 08:08:28 PM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Twospoons
June 03, 2024, 11:13:26 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 03, 2024, 10:35:57 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
June 03, 2024, 05:51:05 PM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Domo
June 03, 2024, 07:41:41 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 03, 2024, 05:28:44 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 03, 2024, 05:02:19 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 03, 2024, 03:47:33 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 03, 2024, 02:23:58 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
June 03, 2024, 01:25:24 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
June 03, 2024, 01:08:47 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 02, 2024, 10:29:02 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
June 02, 2024, 10:02:45 PM
post Re: Racing sparks
[Spark Gap Tesla Coils (SGTC)]
davekni
June 02, 2024, 08:25:37 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
June 02, 2024, 04:51:58 PM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Michelle_
June 02, 2024, 04:44:30 PM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
MRMILSTAR
June 02, 2024, 03:25:11 PM
post APC Smart-UPS 1500VA Teardown
[Electronic Circuits]
Mads Barnkob
June 02, 2024, 01:36:11 PM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
pete_dl
June 02, 2024, 11:43:40 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
June 02, 2024, 08:49:11 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 02, 2024, 08:36:07 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
June 02, 2024, 12:41:50 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Benjamin Lockhart
June 01, 2024, 08:24:35 PM
post Pearson current monitor model 1330 teardown (100kA)
[Laboratories, Equipment and Tools]
Mads Barnkob
June 01, 2024, 08:22:28 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
June 01, 2024, 03:56:53 AM
post Re: Racing sparks
[Spark Gap Tesla Coils (SGTC)]
Terry
June 01, 2024, 12:03:50 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
May 31, 2024, 11:46:20 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 31, 2024, 06:13:59 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
May 31, 2024, 01:55:22 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
May 30, 2024, 11:57:49 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
May 30, 2024, 11:50:06 PM
post First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
May 30, 2024, 11:23:35 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
davekni
May 30, 2024, 10:43:06 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
May 30, 2024, 10:24:35 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
NyaaX_X
May 30, 2024, 06:10:04 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