Author Topic: Best primary coil for SSTC/DRSSTC?  (Read 799 times)

Offline Laci

  • High Voltage Technician
  • ***
  • Posts: 108
  • Karma: +1/-0
    • View Profile
Best primary coil for SSTC/DRSSTC?
« on: March 03, 2018, 10:30:34 PM »
After experimenting a bit with my coil,I wanted to to change the primary,because right at the beginning Mads said that it has too low primary to secondary coupling for SSTC.So now I bought 3 meters of 0.5cm litz copper wire and made 6 tight turns on a plastic cylinder at the bottom of the secondary.The distance between the secondary and primary is 1.5cm.
I tested this setup on a full bridge of mosfets at around 150v,interrupted.It was interesting to see,that the arcs are not longer with this primary than with the "too low coupling" coil.Before this 6 turn primary I also tried more turns of around 0.2cm wire.
I tried different capacitors with the primary.With the 6 turn primary the best output is with 2x220nf caps in series,but not as good as the low coupling coil tapped at around 5 turns,and 3x220nF caps in series,which produced up to 35cm arcs at 150v with high on times!

In conclusion the new primary coil is worse as SSTC and also as DRSSTC setup,while it should be really better at least as SSTC due to lower inductive reactance.What do you recommend to improve on this primary?Should I go back to the lower coupling primary?
« Last Edit: March 04, 2018, 11:00:53 AM by Laci »

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 724
  • Karma: +5/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: Best primary coil for SSTC/DRSSTC?
« Reply #1 on: March 07, 2018, 07:02:28 AM »
That was a bit of a surprise, could you please try to run the numbers on your coil with conical and new tight primary coil through JavaTC and post the results here?
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline Uspring

  • High Voltage Experimenter
  • **
  • Posts: 63
  • Karma: +3/-0
    • View Profile
Re: Best primary coil for SSTC/DRSSTC?
« Reply #2 on: March 09, 2018, 12:50:52 PM »
Metoo, i.e. being surprised. More coupling should improve performance. Here's why:

The primary coupled to the secondary can be modelled by a replacement circuit consisting of an effective primary inductance Leff in series with an effective resistance Reff. The importance of Reff is, that the primary current flows through it and dissipates energy. Actually it is the power consumed by the arc that is being transferred to the secondary then then dissipated by the arc. So the coils interesting power is Ipri^2 * Reff.

For a SSTC driven at resonance, we have the two equations:

Leff = Lpri * (1-k^2)

and

Reff = k^2 * Rarc * Lpri / Lsec

k is the coupling, Lpri and Lsec the primary and secondary inductances and Rarc the resistance of the arc.

Leff and Lpri are quite close to each other with k being around 0.2. Reff is proportional to k^2, so for a given primary current, the power delivered to the arc is also proportional to k^2.

A larger primary inductance Lpri will also increase Reff but at the same time will reduce primary current for a given input voltage due to its higher impedance. So it is best to use the lowest primary inductance as possible. That is limited by the current capabilities of your FETs.



Offline Laci

  • High Voltage Technician
  • ***
  • Posts: 108
  • Karma: +1/-0
    • View Profile
Re: Best primary coil for SSTC/DRSSTC?
« Reply #3 on: March 10, 2018, 08:13:03 PM »
Cheers for the replies.Today I removed the primary from its plastic support to get a bit higher coupling and tested it with my SSTC driver.It works well,but I still can't see any difference with this primary,expect that there are no sparks from secondary to primary at rectified mains.Maybe a bit higher coupling is possible.




« Last Edit: March 10, 2018, 10:43:50 PM by Laci »

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 724
  • Karma: +5/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: Best primary coil for SSTC/DRSSTC?
« Reply #4 on: March 11, 2018, 09:38:34 PM »
Could you please also do the same JavaTC attachment for the conical coil
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline Laci

  • High Voltage Technician
  • ***
  • Posts: 108
  • Karma: +1/-0
    • View Profile
Re: Best primary coil for SSTC/DRSSTC?
« Reply #5 on: March 17, 2018, 10:15:52 PM »
Sorry for the late reply,but I am busy with school things recently... :/
Anyways here are the conical primary informations.Note that the primary has more turns(14) with a total height of 27.5cm,I just ran JavaTC with 6 turns,because the tap point is usually there.
As you can see,the coupling coefficient is higher in both cases then the recommended.


« Last Edit: March 17, 2018, 10:17:25 PM by Laci »

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 724
  • Karma: +5/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: Best primary coil for SSTC/DRSSTC?
« Reply #6 on: March 19, 2018, 11:10:09 AM »
There is virtually no difference between your coils, they have identical inductance and coupling to the secondary coil. There must be something else affecting performance if these simulations reflect the actual setups.

I can not pin point from these why it would perform worse.
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

High Voltage Forum

Re: Best primary coil for SSTC/DRSSTC?
« Reply #6 on: March 19, 2018, 11:10:09 AM »

 


* Recent Topics and Posts

post Re: Drsstc 3
[Dual Resonant Solid State Tesla coils]
oneKone
Today at 02:28:27 AM
post Re: IGBT selection - TO-247 or minibrick?
[Dual Resonant Solid State Tesla coils]
Garyf
September 18, 2018, 05:51:35 PM
post Re: Theremin based on the stm32f103c8t6 and bluepill, stm32duino
[Electronic circuits]
profdc9
September 18, 2018, 05:00:57 AM
post Re: Theremin based on the stm32f103c8t6 and bluepill, stm32duino
[Electronic circuits]
futurist
September 17, 2018, 08:57:40 PM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
Mads Barnkob
September 17, 2018, 11:20:53 AM
post Re: Drsstc 3
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
September 17, 2018, 11:17:23 AM
post Re: mmc capacitor banks
[Spark gap Tesla coils]
Mads Barnkob
September 17, 2018, 08:52:32 AM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
aq62386238
September 16, 2018, 03:31:06 PM
post Re: Drsstc 3
[Dual Resonant Solid State Tesla coils]
profdc9
September 16, 2018, 04:34:36 AM
post Theremin based on the stm32f103c8t6 and bluepill, stm32duino
[Electronic circuits]
profdc9
September 15, 2018, 10:55:33 PM
post Re: Garden flag pole hit by lightning
[General chatting]
profdc9
September 14, 2018, 05:13:33 PM
post Re: mmc capacitor banks
[Spark gap Tesla coils]
profdc9
September 14, 2018, 04:50:48 PM
post Re: Garden flag pole hit by lightning
[General chatting]
OakleyC
September 14, 2018, 12:45:05 AM
post Re: Garden flag pole hit by lightning
[General chatting]
Phoenix
September 13, 2018, 09:59:00 PM
post Re: Garden flag pole hit by lightning
[General chatting]
oneKone
September 13, 2018, 03:34:39 PM
post Garden flag pole hit by lightning
[General chatting]
Mads Barnkob
September 13, 2018, 02:35:00 PM
post Re: Next Gen DRSSTC
[Dual Resonant Solid State Tesla coils]
Netzpfuscher
September 13, 2018, 08:59:50 AM
post Re: mmc capacitor banks
[Spark gap Tesla coils]
OakleyC
September 13, 2018, 02:09:09 AM
post Re: mmc capacitor banks
[Spark gap Tesla coils]
Hydron
September 12, 2018, 04:16:38 PM
post Re: Drsstc 3
[Dual Resonant Solid State Tesla coils]
oneKone
September 12, 2018, 12:21:48 PM
post mmc capacitor banks
[Spark gap Tesla coils]
OakleyC
September 12, 2018, 11:18:07 AM
post Re: Next Gen DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
September 12, 2018, 08:56:06 AM
post Re: IGBT selection - TO-247 or minibrick?
[Dual Resonant Solid State Tesla coils]
Hydron
September 12, 2018, 08:11:12 AM
post Re: IGBT selection - TO-247 or minibrick?
[Dual Resonant Solid State Tesla coils]
Spuriosity_
September 12, 2018, 04:58:28 AM
post Re: Next Gen DRSSTC
[Dual Resonant Solid State Tesla coils]
Hydron
September 10, 2018, 04:31:16 PM
post Re: Next Gen DRSSTC
[Dual Resonant Solid State Tesla coils]
Uspring
September 10, 2018, 01:37:22 PM
post Re: new member seeking advice.
[Solid state Tesla coils]
Mads Barnkob
September 10, 2018, 01:36:14 PM
post Re: Next Gen DRSSTC
[Dual Resonant Solid State Tesla coils]
Netzpfuscher
September 09, 2018, 07:59:44 PM
post Re: new member seeking advice.
[Solid state Tesla coils]
pentode
September 09, 2018, 09:09:22 AM
post Re: new member seeking advice.
[Solid state Tesla coils]
oneKone
September 09, 2018, 08:42:36 AM
post Re: 160mm PLL sstc
[Solid state Tesla coils]
oneKone
September 09, 2018, 08:22:06 AM
post new member seeking advice.
[Solid state Tesla coils]
shogun94
September 08, 2018, 12:57:25 AM
post Re: Non toroid top loads
[Spark gap Tesla coils]
Patric
September 05, 2018, 08:41:36 PM
post Chineese spark aways !
[Solid state Tesla coils]
pentode
September 05, 2018, 02:30:21 PM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
Mads Barnkob
September 05, 2018, 01:43:24 PM
post Re: Non toroid top loads
[Spark gap Tesla coils]
Mads Barnkob
September 05, 2018, 01:42:16 PM
post Re: 160mm PLL sstc
[Solid state Tesla coils]
Mads Barnkob
September 05, 2018, 01:35:07 PM
post Re: 160mm PLL sstc
[Solid state Tesla coils]
oneKone
September 05, 2018, 12:36:22 PM
post Re: Drsstc 3
[Dual Resonant Solid State Tesla coils]
oneKone
September 05, 2018, 12:31:49 PM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
aq62386238
September 05, 2018, 11:59:20 AM
post Re: Non toroid top loads
[Spark gap Tesla coils]
Max
September 05, 2018, 11:52:36 AM
post Re: Drsstc 3
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
September 05, 2018, 10:08:06 AM
post Re: 160mm PLL sstc
[Solid state Tesla coils]
Mads Barnkob
September 05, 2018, 08:36:25 AM
post Re: Drsstc 3
[Dual Resonant Solid State Tesla coils]
oneKone
September 05, 2018, 05:44:25 AM
post Re: 160mm PLL sstc
[Solid state Tesla coils]
oneKone
September 05, 2018, 05:33:32 AM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
aq62386238
September 04, 2018, 04:47:33 PM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
Mads Barnkob
September 04, 2018, 01:51:22 PM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
aq62386238
September 04, 2018, 01:38:46 PM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
Mads Barnkob
September 04, 2018, 12:07:06 PM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
aq62386238
September 04, 2018, 10:51:43 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