Author Topic: SSTC II  (Read 1299 times)

Offline Laci

  • High Voltage Engineer
  • ****
  • Posts: 209
  • Karma: +6/-0
    • View Profile
SSTC II
« on: August 16, 2018, 09:52:20 PM »
After spending a few days with the testing of the driver and assembling the new coil,today I finally hooked it up to rectified mains.The results are amazing!I had no time to make a proper video,but here is a shot from a pretty breakout at a LOW on time.





These are the differences from the previous coil project:
-Smaller secondary coil(40 cm)
-Fullbridge of IRG4PC60U
-The enclosure of the driver(UD 1.3 with antenna feedback)and the inverter's heatsink is grounded
-Feedback from the secondary is received by a real antenna
-Primary coil by 6 and 1/4 turns of thick wire(0.8 cm diameter)for high coupling

The first question is how to calculate the maximum primary current?My IGBTs are rated for 300A peak and I want to keep the current under 200A for safety.
« Last Edit: August 16, 2018, 09:56:19 PM by Laci »

Offline oneKone

  • High Voltage Engineer
  • ****
  • Posts: 263
  • Karma: +6/-0
    • View Profile
Re: SSTC II
« Reply #1 on: August 17, 2018, 02:17:10 AM »
That's an awesome result! The coil and the enclosure look sweet man.

As for the primary current, if you have an oscilloscope you could just make a 1:1000 ct and measure it that way. But one question I have. Is this running as a sstc or a drsstc?

Offline Mads Barnkob

  • Administrator
  • High Voltage Expert
  • *****
  • Posts: 1070
  • Karma: +16/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: SSTC II
« Reply #2 on: August 17, 2018, 07:42:55 AM »
Congratulations on another working coil, looks good and with that amount of topload capacitance I think we will see some serious arcs and exploded silicon ;)

To do an easy primary current calculation you could simplify it as follows: Primary reactance: XL = 2pi * f * L = ? Ohm, use Ohms law to calculate the current by using your peak-to-peak square wave voltage, if you are using 230VAC rectified that is ~320VDC. So Primary current = 320 / XL.
This calculation ignores primary resistance and dc blocking capacitors reactance as they are small factors.
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline Hydron

  • Administrator
  • High Voltage Engineer
  • *****
  • Posts: 242
  • Karma: +7/-0
    • View Profile
Re: SSTC II
« Reply #3 on: August 17, 2018, 08:09:35 AM »
I'd second the recommendation for a CT measurement of primary current. Easiest is to wind two CTs of approx 32 turns each, using the output of the first as the single input turn of the second, giving ~1000:1 total ratio and good high frequency response. A 10R burden resistor then gives a handy 0.01V/A reading.

Offline Laci

  • High Voltage Engineer
  • ****
  • Posts: 209
  • Karma: +6/-0
    • View Profile
Re: SSTC II
« Reply #4 on: August 17, 2018, 12:18:22 PM »
Thanks for the replies!

@Hydron and @oneKone
I wanted to calculate the maximum primary current before running it at full power,so I can be sure that it will not blow.I have two sets of ~1000 current transformers,which I used before as OCD.Not sure if they lowers the performance or not as SSTC operation.

@Mads Barnkob
The main reason for using the upper topload was to lower the resonant frequency to make switching easier.By the way it improved the performance and increased the input current significantly and it might cause primary flashovers just like your SSTC.A capacitor between the negative of the bridge and ground would be a good idea I think.

I calculated the primary inductance using JavaTC.It is around 8uH.At 170kHz this means about 8.5 ohm inductive reactance,which should limit the current under 38A.Now the real problems begin.What else can cause silicone breakdown? :)

Offline Laci

  • High Voltage Engineer
  • ****
  • Posts: 209
  • Karma: +6/-0
    • View Profile
Re: SSTC II
« Reply #5 on: October 28, 2018, 07:15:05 PM »
Hello again!  :)
In this week I had two presentations with this coil on my school's physics show.It was working on the first day,but on the second day after I cranked up the on-time over half on the oneTesla interrupter(lookup table scale 10)it stopped working and the fuse blown silently.It's not a big shame,since it was working for about 15 minutes before it died.After taking the bridge apart a low side transistor and it's high side pair's diode was dead(don't know yet if the 440V TVS or the MUR1560).I think a spike killed the diode and then the transistor was short circuited.If the 440 TVS failed is it recommended to omit them or switch to a higher voltage TVS?Also the previous time the bridge blown by almost the same reason,running it at highish on-time for a few seconds.


I'm planning to make a better full bridge layout.I want to still use TO-247 transistors as they are cheap.Is there any way to make a low inductance single side(maybe etched)board?

Offline Laci

  • High Voltage Engineer
  • ****
  • Posts: 209
  • Karma: +6/-0
    • View Profile
Re: SSTC II
« Reply #6 on: November 09, 2018, 06:20:53 PM »
Today I received a package containing two LARGE EPCOS B43586-S3468-Q1 4600uF 385V capacitors.They are really overkill for this medium sized coil with a HGTG30N60A4D fullbridge even though more is better than less :) I am thinking about selling them,maybe create a post on the marketplace.They were used,but their capacity is right accordingly to my multimeter.

I started again the assembly of the coil today and figured out that I used bidirectional TVS diodes instead of unidirectional ones(1.5KE440A instead of 1.5KE440CA).Pretty stupid mistake!
One problem I already have is the charging of the DC bus capacitor.In the past I used a resistor to charge it and a switch to bypass the resistor,but with this setup the switch can be a problem with one of these large capacitors at huge currents,because the high current flows through the switch.The other possible solution is leaving the capacitors connected to the bridge and put a resistor with bypass switch in series with rectified mains.This way I will be able to use half or full wave rectified mains for sword-like sparks only if I unscrew the capacitor.







« Last Edit: November 09, 2018, 06:22:40 PM by Laci »

Offline Mads Barnkob

  • Administrator
  • High Voltage Expert
  • *****
  • Posts: 1070
  • Karma: +16/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: SSTC II
« Reply #7 on: November 11, 2018, 10:13:09 PM »
Those are some serious overkill capacitors!

To prevent inrush current, how about adding bleeder resistors to them? Which will also help empty them to a safe state after a few minutes: http://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/dc-bus-capacitor/

http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

High Voltage Forum

Re: SSTC II
« Reply #7 on: November 11, 2018, 10:13:09 PM »

 


* Recent Topics and Posts

post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
Bert911
Today at 01:04:35 PM
post Re: You would think this would be easy to find.
[Spark gap Tesla coils]
thedoc298
August 17, 2019, 11:09:16 PM
post Re: You would think this would be easy to find.
[Spark gap Tesla coils]
thedoc298
August 17, 2019, 11:00:32 PM
post Re: You would think this would be easy to find.
[Spark gap Tesla coils]
Fumeaux
August 17, 2019, 09:44:07 PM
post You would think this would be easy to find.
[Spark gap Tesla coils]
thedoc298
August 17, 2019, 09:01:00 PM
post Re: Twin System Build
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
August 17, 2019, 08:06:42 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
Lane
August 17, 2019, 10:45:26 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
Lane
August 17, 2019, 06:21:45 AM
post Re: My second DRSSTC
[Dual Resonant Solid State Tesla coils]
Hydron
August 17, 2019, 12:59:20 AM
post Re: Twin System Build
[Dual Resonant Solid State Tesla coils]
fnordest
August 17, 2019, 12:18:48 AM
post Re: Drsstc 3
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
August 16, 2019, 10:34:46 PM
post Re: Teardown of Danfoss VLT6000 4kW Variable Frequency Drive
[Electronic circuits]
Mads Barnkob
August 16, 2019, 10:26:19 PM
post Re: My second DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
August 16, 2019, 10:19:18 PM
post Re: [Development] Project of an SSTC driver.
[Solid state Tesla coils]
Mads Barnkob
August 16, 2019, 10:07:31 PM
post Re: Suitable capacitors and switches? 10kV
[Capacitor banks]
T3sl4co1l
August 16, 2019, 09:28:35 PM
post Re: Suitable capacitors and switches? 10kV
[Capacitor banks]
ElectroXa
August 16, 2019, 09:17:04 PM
post Re: ESAB Power TIG 200 Welder Teardown
[Electronic circuits]
T3sl4co1l
August 16, 2019, 09:14:36 PM
post ESAB Power TIG 200 Welder Teardown
[Electronic circuits]
Mads Barnkob
August 16, 2019, 08:03:18 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
August 16, 2019, 01:49:53 PM
post Suitable capacitors and switches? 10kV
[Capacitor banks]
MrFox
August 16, 2019, 12:21:36 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
Lane
August 16, 2019, 11:22:45 AM
post Re: Small Phase change build R600a
[General chatting]
DashApple
August 15, 2019, 06:23:40 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
rikkitikkitavi
August 15, 2019, 06:17:55 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
Lane
August 15, 2019, 01:51:04 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
August 14, 2019, 07:05:57 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
Bert911
August 14, 2019, 03:42:34 PM
post Re: Van de Graaf is leaking charge
[Static electricity]
Patric
August 14, 2019, 02:56:49 PM
post Re: Van de Graaf is leaking charge
[Static electricity]
ElectroXa
August 14, 2019, 01:42:21 PM
post Re: My second DRSSTC
[Dual Resonant Solid State Tesla coils]
erdal
August 14, 2019, 12:53:10 PM
post Van de Graaf is leaking charge
[Static electricity]
Patric
August 14, 2019, 09:22:21 AM
post Re: Drsstc 3
[Dual Resonant Solid State Tesla coils]
oneKone
August 14, 2019, 04:39:11 AM
post Re: MMC orientation and variac
[Spark gap Tesla coils]
thedoc298
August 13, 2019, 07:10:31 PM
post Re: MMC orientation and variac
[Spark gap Tesla coils]
MRMILSTAR
August 13, 2019, 05:17:23 AM
post MMC orientation and variac
[Spark gap Tesla coils]
thedoc298
August 12, 2019, 09:54:35 PM
post Re: My second DRSSTC
[Dual Resonant Solid State Tesla coils]
erdal
August 12, 2019, 08:40:16 PM
post Re: Small Phase change build R600a
[General chatting]
Hydron
August 12, 2019, 07:27:23 PM
post Re: Teardown of Danfoss VLT6000 4kW Variable Frequency Drive
[Electronic circuits]
klugesmith
August 12, 2019, 09:18:15 AM
post Re: Teardown of Danfoss VLT6000 4kW Variable Frequency Drive
[Electronic circuits]
shrad
August 12, 2019, 09:06:34 AM
post Re: Teardown of Danfoss VLT6000 4kW Variable Frequency Drive
[Electronic circuits]
klugesmith
August 12, 2019, 09:02:38 AM
post Re: A problem solved with hand tools
[General chatting]
klugesmith
August 12, 2019, 08:29:20 AM
post Re: Ebay [US]: MITSUBISHI CM300 1200V-300A IGBT (30$ a piece)
[Sell / Buy / Trade]
oneKone
August 12, 2019, 05:25:24 AM
post Re: Ebay [US]: MITSUBISHI CM300 1200V-300A IGBT (30$ a piece)
[Sell / Buy / Trade]
acobaugh
August 10, 2019, 08:14:35 PM
post Re: 30% power increase
[Spark gap Tesla coils]
MRMILSTAR
August 08, 2019, 04:18:09 PM
post Re: "LightningStorm" VTTC project
[Vacuum tube Tesla coils]
Bambinz
August 08, 2019, 01:15:11 PM
post Re: Twin System Build
[Dual Resonant Solid State Tesla coils]
Bambinz
August 08, 2019, 12:15:26 PM
post Re: My second DRSSTC
[Dual Resonant Solid State Tesla coils]
Bambinz
August 08, 2019, 11:58:47 AM
post Re: [Development] Project of an SSTC driver.
[Solid state Tesla coils]
Bambinz
August 08, 2019, 11:56:51 AM
post Re: Next Gen DRSSTC
[Dual Resonant Solid State Tesla coils]
Netzpfuscher
August 08, 2019, 10:04:39 AM
post Re: My second DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
August 08, 2019, 08:35:57 AM
post Re: 30% power increase
[Spark gap Tesla coils]
Mads Barnkob
August 08, 2019, 08:33:01 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