Author Topic: DRSSTC design guide - progress report  (Read 1054 times)

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 577
  • Denmark
    • View Profile
    • Kaizer Power Electronics
DRSSTC design guide - progress report
« on: March 21, 2017, 10:43:04 AM »
Hello all

This is my attempt to write a long guide about practical DRSSTC design. I try to cover the most critical design issues in a way that most electronics interested should be able to understand. I have tried to hand pick the necessary theory and calculations to our specific purposes of building a DRSSTC.

It is a work in progress and I would like to invite you all to help me make it better, correct and add more topics.

Topics of the DRSSTC design guide
01. Rectifiers (done)
02. Busbar and primary circuit (done)
03. IGBTs (done)
04. DC bus capacitor (done)
05. PFC (20% done)
06. Snubber capacitor (done)
07. MMC / tank capacitors (10% done)
08. GDT / driver (5% done)
09. Secondary coil (done)
10. Topload (done)
11. Grounding and EMI (done)
12. Tuning and testing (10% done)
13. Featured Tesla coils (0% done)
14. DRSSTC FAQ
15. Online design tools

I hope this guide can help others to understand why and how components are chosen for a DRSSTC.

This thread will serve as a status for the complete guide, when I add new data it will be posted here.
« Last Edit: April 08, 2018, 10:34:47 PM by Mads Barnkob »
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline Tardief

  • High Voltage Enthusiast
  • *
  • Posts: 30
    • View Profile
Re: DRSSTC design guide - progress report
« Reply #1 on: June 22, 2017, 11:44:59 PM »
Hi,
We are planning to build a Tesla Coil with 4x CM600HA-24H. I saw in your list that it failed at 56kHz. Could you explain me what thas it mean? Unfortunately i cant find it at 4hv forum and i cant post there.
Should we make the secondary for a lower frequency?
Thanks

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 577
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: DRSSTC design guide - progress report
« Reply #2 on: June 23, 2017, 10:01:04 AM »
Hi,
We are planning to build a Tesla Coil with 4x CM600HA-24H. I saw in your list that it failed at 56kHz. Could you explain me what thas it mean? Unfortunately i cant find it at 4hv forum and i cant post there.
Should we make the secondary for a lower frequency?
Thanks

You should naturally get a much lower resonant frequency than 56 kHz with such a large brigde, simply because you need some height for the 5+ meter long sparks, so you will properly end up around 35 kHz. Failure at 3500 Ampere peak is also extremely high, you can run yours at 2000 Ampere and still have solid sparks :)

I am looking forward to see a build thread on this huge Tesla coil  :o
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline Tardief

  • High Voltage Enthusiast
  • *
  • Posts: 30
    • View Profile
Re: DRSSTC design guide - progress report
« Reply #3 on: June 23, 2017, 06:26:04 PM »
Thanks!
Will do.   :)

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 577
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: DRSSTC design guide - progress report
« Reply #4 on: April 08, 2018, 10:36:36 PM »
I have finally finished the chapter 11 on Grounding and EMI, you can read it here: http://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/grounding-circuit-protection-and-emi/

Please do ask questions and come with feedback on how to improve the chapter or if there is any errors :)
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline profdc9

  • High Voltage Technician
  • ***
  • Posts: 100
    • View Profile
Re: DRSSTC design guide - progress report
« Reply #5 on: April 08, 2018, 10:57:30 PM »
Mads,

One question I have is this, and it may be related to EMI/grounding issues.  Yesterday I was working on getting my through-hole UD2.7C board to work with my tesla coil.  I set up the Tesla coil to tune the lead inductor by placing three soup cans inside the primary coil where the secondary coil should be.  I plugged in the gate transformer to the UD2.7C, as well as the two current transformers for feedback and overcurrent.

I have my primary bus on a variac and set to a low voltage (around 30 VAC with the line voltage being 120 VAC) and placed a 100X probe to monitor one leg of the full bridge with the ground clip on the earthing ground and the other clipped onto the bus lead on the full bridge.  I am using a voltage doubler.  The other I had clipped to the ground of the UD2.7C board and a test point so I can monitor the bus current.

Things were going ok.  The bus voltage looks very noisy and ringing, but the bus current seems to grow and then recede after the interrupter turns off.  So far so good.  Then suddenly my UD2.7C board stops working.   I have checked the solder connections, and can't anything wrong.  The 74HC08 chip goes bad.  I replace it, and then the 74HC74 chip goes bad, and I replace the 74HC14 chip because I figured something happened.  Then for some reason the 74HC08 chip goes bad again!  And I have to replace that...

Should I put common-mode chokes on the gate driver as well as the feedback and overcurrent transformers?  I think I will try that anyways, but I am wondering if there are voltage spikes making their way into the board from the full bridge.  I tried to stick to the UD2.7C as closely as I could when laying out the circuit, however, I did have to change the undervoltage lockout circuit because there was no through-hole available part.

I also soldered a 5.1V zener diode on the 5V supply to try to absorb any transients as well.  Any suggestions?

Thanks,

Dan

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 577
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: DRSSTC design guide - progress report
« Reply #6 on: April 09, 2018, 09:06:08 PM »
Mads,

One question I have is this, and it may be related to EMI/grounding issues.  Yesterday I was working on getting my through-hole UD2.7C board to work with my tesla coil.  I set up the Tesla coil to tune the lead inductor by placing three soup cans inside the primary coil where the secondary coil should be.  I plugged in the gate transformer to the UD2.7C, as well as the two current transformers for feedback and overcurrent.

I have my primary bus on a variac and set to a low voltage (around 30 VAC with the line voltage being 120 VAC) and placed a 100X probe to monitor one leg of the full bridge with the ground clip on the earthing ground and the other clipped onto the bus lead on the full bridge.  I am using a voltage doubler.  The other I had clipped to the ground of the UD2.7C board and a test point so I can monitor the bus current.

Things were going ok.  The bus voltage looks very noisy and ringing, but the bus current seems to grow and then recede after the interrupter turns off.  So far so good.  Then suddenly my UD2.7C board stops working.   I have checked the solder connections, and can't anything wrong.  The 74HC08 chip goes bad.  I replace it, and then the 74HC74 chip goes bad, and I replace the 74HC14 chip because I figured something happened.  Then for some reason the 74HC08 chip goes bad again!  And I have to replace that...

Should I put common-mode chokes on the gate driver as well as the feedback and overcurrent transformers?  I think I will try that anyways, but I am wondering if there are voltage spikes making their way into the board from the full bridge.  I tried to stick to the UD2.7C as closely as I could when laying out the circuit, however, I did have to change the undervoltage lockout circuit because there was no through-hole available part.

I also soldered a 5.1V zener diode on the 5V supply to try to absorb any transients as well.  Any suggestions?

Thanks,

Dan

The switching spikes is first and foremost from low voltage testing, I put some information about that in another thread with links to read more about that: https://highvoltageforum.net/index.php?topic=259.msg1685#msg1685

Is your oscilloscope grounded through the mains plug? Else you might just be shunting noise through the common ground in the oscilloscope between the inverter and driver ground.

Do you have any unused input pins on the 74xx ICs that is ungrounded? That can make them act up very weird from crosstalk.
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline Laci

  • High Voltage Experimenter
  • **
  • Posts: 86
    • View Profile
Re: DRSSTC design guide - progress report
« Reply #7 on: April 09, 2018, 11:24:48 PM »
Around a week ago,while I was running my SSTC at low currents(so short arcs)the nearby laptop got crazy.The wirless mouse stopped working and no longer could I use it.It's interesting that my ~160kHz coil destroyed a 2.4GHz device.Maybe bad grounding or unstable tuning can cause really high frequency harmonics,or just the too large magnetic field internally blown up the mouse.
Another thing is the FM range.I wonder how many of my neighbours are able to listen to the radio while my coil is running :P.
« Last Edit: April 09, 2018, 11:28:35 PM by Laci »

Offline profdc9

  • High Voltage Technician
  • ***
  • Posts: 100
    • View Profile
Re: DRSSTC design guide - progress report
« Reply #8 on: April 10, 2018, 02:43:19 AM »
The switching spikes is first and foremost from low voltage testing, I put some information about that in another thread with links to read more about that: https://highvoltageforum.net/index.php?topic=259.msg1685#msg1685

Is your oscilloscope grounded through the mains plug? Else you might just be shunting noise through the common ground in the oscilloscope between the inverter and driver ground.

Do you have any unused input pins on the 74xx ICs that is ungrounded? That can make them act up very weird from crosstalk.

My oscilloscope is grounded through the mains.  I double-checked it with a continuity checker, no problem there.

The UD2.7C board doesn't have any ungrounded pins in the layout, I made sure of that.  So I don't think that's the case.

Yesterday I ran the board and so far it seems to be holding up.  Maybe I was careless about ESD handling?  At any rate, I ordered some more replacement chips from Digikey in case something else goes wrong.  I also put common-mode chokes on the transformers as well (three turns around a small ferrite toroid).

I actually have some traces from yesterday in this thread ( https://highvoltageforum.net/index.php?topic=302.msg1909;topicseen#new ).  I have some weird ringing that I am working on troubleshooting.  I have a full bridge of FGH60N60SMD IGBT's so it's nothing too difficult to drive I think; I only have 2 kW available from my home circuits to work with.  I am not sure yet if the ringing is an artifact of the way I'm probing the bridge or if its actually there.  Certainly the overshoot seems to change as I increase the voltage.  I have been able to get it to operate for a few half cycles without OCD trip at 300 A at full voltage with soup can load. 

I reread the thread you pointed to and I am not really having a problem with slow rise time, mostly just these weird ringing artifacts.  I'll keep looking.  I have read that the primary coil itself can have self-resonance that can cause oscillations on the bus signal.

Dan

Offline sparkydownunder

  • High Voltage Enthusiast
  • *
  • Posts: 8
    • View Profile
Re: DRSSTC design guide - progress report
« Reply #9 on: April 10, 2018, 02:14:54 PM »
Hi Mads

Your post on grounding and EMI dosent seem to have a conclusive suggestion for proper grounding. Im going to be using my coil at home and on the road a bit.

If i use a line filter on my earth connection I should still avoid using my existing house earth correct (even if running in the garden)? What do you use for your testing? what size spike/plate?

thanks in advance and thanks for your amazing guide! Im so close and wouldnt be where i am without it :)

Offline profdc9

  • High Voltage Technician
  • ***
  • Posts: 100
    • View Profile
Re: DRSSTC design guide - progress report
« Reply #10 on: April 12, 2018, 08:04:24 PM »
I wouldn't use your mains earth ground to ground your Tesla coil.  You can use a counterpoise to ground the secondary coil, which is basically a large metal sheet you spread on the floor under the Tesla coil.  It can be as simple as taped together aluminium foil, chicken coop wire, metal window screen material, or my preferred material, aluminium roof flashing, because it is not crinkly, and if you round of the corners you will get less arcing there.  The wire to the counterpoise should not be too long or else the inductance of the wire will be too large and the counterpoise is not effective.  Also, ground the bottom of the secondary coil to the strike ring as well.  Make sure the wire to the counterpoise is not routed near anything else, or the secondary might arc to those other objects.

Dan

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 577
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: DRSSTC design guide - progress report
« Reply #11 on: April 15, 2018, 09:54:45 PM »
Hi Mads

Your post on grounding and EMI dosent seem to have a conclusive suggestion for proper grounding. Im going to be using my coil at home and on the road a bit.

If i use a line filter on my earth connection I should still avoid using my existing house earth correct (even if running in the garden)? What do you use for your testing? what size spike/plate?

thanks in advance and thanks for your amazing guide! Im so close and wouldnt be where i am without it :)

Because there is no conclusive suggestion, it is very dependable on the specific situation. It is hard to point out one good solution when there is very little data to back it up with, but on the other hand there is a great deal of information on what not to do.

I have used single rod grounding systems, from smallest to my largest drsstc, but we also have a good moist and highly conductive soil in Denmark.
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

High Voltage Forum

Re: DRSSTC design guide - progress report
« Reply #11 on: April 15, 2018, 09:54:45 PM »

 


* Recent Topics and Posts

post Re: On frequency splitting
[Dual Resonant Solid State Tesla coils]
Teravolt
Today at 03:40:02 PM
post Re: On frequency splitting
[Dual Resonant Solid State Tesla coils]
Teravolt
Today at 03:34:16 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
Hydron
Today at 03:07:11 PM
post Re: Micro drsstc
[Dual Resonant Solid State Tesla coils]
oneKone
Today at 02:58:51 PM
post Re: On frequency splitting
[Dual Resonant Solid State Tesla coils]
Uspring
Today at 12:57:37 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
Uspring
Today at 12:26:05 PM
post Re: Where Can I find this form factor Snubber capacitors??
[Dual Resonant Solid State Tesla coils]
Phoenix
April 24, 2018, 11:41:03 PM
post Re: How to test high power DRSSTC with residential circuits?
[Dual Resonant Solid State Tesla coils]
profdc9
April 24, 2018, 07:09:04 PM
post Re: On frequency splitting
[Dual Resonant Solid State Tesla coils]
TDAF
April 24, 2018, 06:35:50 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
TDAF
April 24, 2018, 06:34:09 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
Hydron
April 24, 2018, 06:32:18 PM
post Re: On frequency splitting
[Dual Resonant Solid State Tesla coils]
Hydron
April 24, 2018, 06:29:41 PM
post On frequency splitting
[Dual Resonant Solid State Tesla coils]
TDAF
April 24, 2018, 06:23:49 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
TDAF
April 24, 2018, 05:42:20 PM
post Re: Where Can I find this form factor Snubber capacitors??
[Dual Resonant Solid State Tesla coils]
TDAF
April 24, 2018, 05:37:23 PM
post Re: Planned short shelf life on component level will threat the future of "vintage"
[Electronic circuits]
petespaco
April 24, 2018, 04:57:54 PM
post Re: Micro drsstc
[Dual Resonant Solid State Tesla coils]
Hydron
April 24, 2018, 04:36:38 PM
post Re: Micro drsstc
[Dual Resonant Solid State Tesla coils]
oneKone
April 24, 2018, 02:42:09 PM
post Re: How to test high power DRSSTC with residential circuits?
[Dual Resonant Solid State Tesla coils]
Hydron
April 24, 2018, 02:06:32 PM
post Re: How to test high power DRSSTC with residential circuits?
[Dual Resonant Solid State Tesla coils]
the_anomaly
April 24, 2018, 02:00:08 PM
post Re: How to test high power DRSSTC with residential circuits?
[Dual Resonant Solid State Tesla coils]
Hydron
April 24, 2018, 01:41:39 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
Hydron
April 24, 2018, 01:08:45 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
Uspring
April 24, 2018, 12:52:40 PM
post Re: Micro drsstc
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
April 24, 2018, 12:34:11 PM
post Re: Micro drsstc
[Dual Resonant Solid State Tesla coils]
oneKone
April 24, 2018, 09:59:13 AM
post Re: Why no one uses MKP "Motor Run" Capacitors?
[Beginners]
Dr.Krieger
April 24, 2018, 05:00:00 AM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
Hydron
April 24, 2018, 12:05:42 AM
post Re: Progress and circuit breaker tripped
[Dual Resonant Solid State Tesla coils]
Hydron
April 23, 2018, 11:50:50 PM
post Re: Current sharing in QCW inverters
[Dual Resonant Solid State Tesla coils]
Paultesla
April 23, 2018, 11:20:53 PM
post Re: Progress and circuit breaker tripped
[Dual Resonant Solid State Tesla coils]
profdc9
April 23, 2018, 10:20:04 PM
post Re: How to test high power DRSSTC with residential circuits?
[Dual Resonant Solid State Tesla coils]
profdc9
April 23, 2018, 10:10:20 PM
post Re: Progress and circuit breaker tripped
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
April 23, 2018, 10:04:57 PM
post Re: Where Can I find this form factor Snubber capacitors??
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
April 23, 2018, 09:58:55 PM
post Re: Why no one uses MKP "Motor Run" Capacitors?
[Beginners]
Mads Barnkob
April 23, 2018, 09:43:53 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
Teravolt
April 23, 2018, 09:34:51 PM
post Re: Micro drsstc
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
April 23, 2018, 09:25:05 PM
post Re: How to test high power DRSSTC with residential circuits?
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
April 23, 2018, 09:00:57 PM
post QCW Buck Questions
[Dual Resonant Solid State Tesla coils]
alan sailer
April 23, 2018, 08:12:12 PM
post Re: How to test high power DRSSTC with residential circuits?
[Dual Resonant Solid State Tesla coils]
Netzpfuscher
April 23, 2018, 07:08:20 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
Uspring
April 23, 2018, 06:52:30 PM
post Re: OneTesla SD Interrupter extending On-Time?
[Dual Resonant Solid State Tesla coils]
futurist
April 23, 2018, 06:37:53 PM
post Re: How to test high power DRSSTC with residential circuits?
[Dual Resonant Solid State Tesla coils]
Teravolt
April 23, 2018, 06:32:05 PM
post How to test high power DRSSTC with residential circuits?
[Dual Resonant Solid State Tesla coils]
profdc9
April 23, 2018, 04:12:29 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
TDAF
April 23, 2018, 02:46:11 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
Uspring
April 23, 2018, 02:43:30 PM
post Re: Regarding the Ward QCWDRSSTC
[Dual Resonant Solid State Tesla coils]
TDAF
April 23, 2018, 01:04:56 PM
post Re: Le Koo Cee Dubloo
[Dual Resonant Solid State Tesla coils]
TDAF
April 23, 2018, 12:15:47 PM
post Re: Current sharing in QCW inverters
[Dual Resonant Solid State Tesla coils]
TDAF
April 23, 2018, 10:58:00 AM
post Re: Current sharing in QCW inverters
[Dual Resonant Solid State Tesla coils]
Steve Ward
April 23, 2018, 03:42:50 AM
post Re: Why no one uses MKP "Motor Run" Capacitors?
[Beginners]
Dr.Krieger
April 23, 2018, 03:23:37 AM