Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - profdc9

Pages: [1] 2 3 ... 10
1
Transformer (ferrite core) / Re: How to design a 7.5kV AC source?
« on: January 18, 2019, 04:25:14 PM »
I'll venture a solution...

Use a full-bridge or H-bridge of MOSFETS such as the IRF820, where each side is driven by two 50% duty cycle square wave signals of different frequencies with a difference between the frequencies that is the output frequency you want that would drive both sides of a small ferrite transformer primary.  For example, if you want 1 kHz, you would drive one side perhaps with 200 kHz, the other with 201 kHz.   You could rectify mains power for example to power the H-bridge, for example, from 220 VAC to 300 VDC, with a full-wave rectifier, and use a buck converter or even a small variac on the primary side to adjust the DC voltage on the bridge.  A ferrite transformer, for example, with a 10:350 turn ratio so that you could transform the 300 VDC voltage up to the 7.5 kVAC range.  A high voltage polypropylene capacitor (perhaps 1000 pF?) would need to be placed on the secondary output of the transformer to filter high frequency (200 kHz) and leave a clean sine wave, or you might have to build a pi lowpass filter if you want the high harmonics really attenuated.   You will probably also need a DC block capacitor as well in series with the primary winding.   What I've described is open loop and I think to close the loop you would need to use an optoisolator to feedback a signal to the buck converter to regulate the voltage, or you could just put a resistive load (like a 10 megaohm 10 watt resistor) to try to provide some stability to the output voltage and act as a bleeder resistor if you don't need super accurate output voltage.

Dan



2
General chatting / Re: 迎词、来
« on: January 10, 2019, 06:56:59 PM »
I too made a pulse skip driver, based on analog hardware (the UD 2.7c).

If you have been able to get sword-like sparks, or even some interesting results using pulse skip behavior, please share it.

The driver I designed is at

https://github.com/profdc9/DRSSTC-PCB-Pack/tree/master/ud29

And the thread where I show the waveforms and results is

https://highvoltageforum.net/index.php?topic=346.0

Thanks for any experience you can shared about your pulse skip driver behavior.

Dan

Hi, everyone.           
I am a 24-year-old Tesla coil hobbyist from Wuhan, China.
My job is Chip Technology Support Engineer.   
       
I have 11 years of Tesla Coil hobby experience.           
The first Tesla coil was made by winding the coil with a mineral water bottle. The arc was only 2 cm. ;D           
At present, I have done DRSSTC, QCWDRSSTC and some CLASSE design experience.     
     
 I just finished the design of "Yunbao" jump pulse driver the year before last, see it           
https://4hv.org/e107_plugins/forum/forum_viewtopic.php?id=179388
This is part of my work page.
https://i.youku.com/i/UMTEyMDQ1MzYw/videos?spm=a2hzp.8244740.0.0

‘Yunbao’pulse skipping driver

Recently, I am developing UD3.3A for full digital signal input phase shifting.


At present, I am completing the work of writing the hardware logic of the phase shifting part of the alternating hard switch bridge arm.
Hope to share with you more! Thank you!  :D

3
Hello, and happy new year!

I laid out a version of the board that is mostly SMT 0805 for those who prefer that.  You can find it at

http://github.com/profdc9/VNA

A picture of it is below.

As a note, I was thinking about how to make the choke more broadband.  I think it could be done if the choke was a 50 ohm coax such as RG-174 or RG-58 wrapped 5-10 times around a high permeability MnZn ferrite like would be used for a GDT.    I think such a choke could probably work all the way from 30 kHz to 500 MHz.  The only disadvantage is that the impedance range of the analyzer might be reduced a little on the high end because of the capacitance of the coax adding a shunt reactance, so keeping the coax as short as possible is important.  I am not sure how to add a switchable capability unless I put a jumper block on the board to switch as the issue is that the parasitics a toggle switch would introduce would likely reduce the range of the impedance analyzer itself.  It's very tricky to get something to work over many decades of frequency.

Dan



4
I haven't hooked it up to the analyzer yet to the coil, but I'll give it a try sometime.  Mostly done antennas and filters and the like, but it should be able to measure the impedance of anything you can clip leads to.

I was thinking of adding a crude spectrum analyzer and frequency counter/measurement capability to it as well.  The second port receive port could be used with a frequency swept source to perform some spectrum analysis with up to 10 kHz IF bandwidth.  The dynamic range won't be great, but it doesn't cost anything except some additional software to write.  Also it is possible to count pulses with the microcontroller so as long as I get the frequency of the LO within 10 kHz of the signal to be counted, the pulses could be counted to determine the signal frequency by adding the measured frequency and the LO.  These features will be slow but the hardware needed to support them is already on the board and is minimal.

Dan

Thank you very much for sharing Dan, you got such a pace at new designs and implementation of existing ideas to fit the Tesla coil and high voltage branch.

I would very much like to give this a go as I only have a special audio dedicated spectrum analyzer and the spectrum analyzer functionality on the Rigol DS1054z is very rough. So a 30 kHz to ~500MHz would make a nice addition to the instrument shelf. With a simple selector switch different chokes could be selected between for different measurement ranges.

Did you try to make some measurements with a simulated load on the secondary coil? If you add a piece of thin copper wire with 6 smaller branches on it, that in size corresponds to the spark output it would give and compare that with unloaded results.

5
General chatting / Re: Merry Christmas and Happy New Year to everyone!
« on: December 23, 2018, 04:52:06 PM »
Thanks Mads for running the forum and support HV hobbyists!  Merry christmas to you and your family.  Let's all hope for all kinds of new ideas and experimentation in 2019 and keep things fresh and interesting.

Glædelig Jul og Godt Nytår!

Dan


6
You can find the git project at

https://github.com/profdc9/VNA

What is a vector network analyzer? It is a tool for measuring impedance, reflection, and transmission.  The one I designed works on one port from about 30 kHz to 470 MHz, and on two ports from about 300 kHz to 470 MHz (though I have not tested transmission that much this high).

How does it work?  You connect a short, open, and 50 ohm load to the transmit port to calibrate the reflection, and then connect the transmit to to receive port to calibrate the transmission.  Then you can connect a load to either the transmit port, or from the transmit to the receive port, and get its impedance or transmission/reflection characteristics.

What can this do for coilers?  You could connect it to your coil and directly measure the impedance of your coil.  For example, if your system has multiple resonances, you can sweep them with very fine frequency resolution and see the upper and lower frequencies.  You can also directly measure the "Q" of your coil for example.  Basically it can measure impedances between about 2 and 10000 ohms at RF frequencies.

Does it cost a lot?  Probably about $40 in parts or so to build.  I tried to make it as easy as possible, it uses mostly through-hole parts but one surface mount part.  It even has a touchscreen.  I designed it mostly for ham radio use at HF/VHF, but it should be useful down to 30 kHz.  To be more usable at lower frequencies, it is best to put a slightly bigger common-mode choke onto it, which will make the minimum frequency lower at the expense at somewhat reducing the maximum frequency because of parasitic effects between the turns in the choke.  But even with a bigger choke it should be usable at least to 200 MHz I think.  Here's some pictures of it in action.







You can also hook it to USB and looks like a USB serial device and you can type commands at it to get data off of it.

Anyways, I know this is not high voltage, but it could be useful for high frequency circuits in high voltage.

Dan


7
Dual Resonant Solid State Tesla coils / Re: TO-247 IGBT for DRSSTC
« on: November 12, 2018, 08:35:12 PM »
I have not used the transistors you are talking about but looking at the data sheet they seem to be limited to 280 A also.  I used the FGH60N60SMD on my DRSSTC, and two of those in parallel, to have a full bridge of 8 transistors total, and so far it has held up to all the abuse I have subjected it to.  According to the data sheet these only have 180 A peak pulsed collector current relative as compared to the transistors you selected, however, the maximum power dissipation and average collector current ratings are higher.  I'm not sure why it would be this way, as I would think that the average and maximum peak currents would scale together.  I have attached the datasheets for both for you to look at.  I have been intended to try a different IGBT with nearly identical characteristics to the FGH60N60SMD but unfortunately with lower maximum power dissipation rating because the FGH60N60SMD seems hard to get these days.

Dan

http://www.onsemi.com/pub/Collateral/FGH60N60SMD_F085-D.PDF

Hi Dan,
I know this post is a bit outdated,but do you remember if the 20N60A4D's had the 300A limitation?I just want to know the possibilities of my current SSTC setup for upgrading to a DRSSTC.My transistors are 30N60A4D's with a lower pulse current rating than the 20N60A4D's(240A and 280A) in a full bridge configuration.

8
General chatting / Re: Hallloowweeen
« on: November 03, 2018, 04:35:07 PM »
I considered getting videos, but some parents get kind of uppity when you video their kids, so I decided against it.  I have to say though that by-and-large the people in my neighborhood have been fairly tolerant and open to the crazy neighbor that creates lightning in his garage. :)

Dan

Nice with a little local display, did you get any videos of it?

Halloween is not a big deal in Denmark (only shops and commercial interests tries really hard to make it a thing to sell more stuff), there is a few kids or houses with a little decoration. We have our "kids dress up" holiday in February called Fastelavn https://en.wikipedia.org/wiki/Fastelavn

9
General chatting / Hallloowweeen
« on: November 01, 2018, 04:19:50 AM »
Hello,

I just wanted to mention that tonight I set up my Tesla coil and it was a big hit with the kids in the neighborhood.  Nothing excites the trick-or-treaters like a musical lightning machine on Halloween.  I played Hall of the Mountain King, Night on Bald Mountain, Toccata and Fugue, Funeral March of the Marionettes, as well as other tunes.

Dan

10
I don't want to threadjack, but I have worked on a PCB layout for this

https://github.com/profdc9/DRSSTC-PCB-Pack/tree/master/full-bridge-multi

The snubbers should be placed very close to the emitter/collectors of the IGBTs I think.  In the design below, there are two snubbers that are placed in between the hi and low side of the half bridges.  The PCB layout uses almost all of the copper on the board to try to minimize inductance.

If the snubbers are very close to the emitter/collectors than there is a bit more tolerance of the connection of the bus cap.  I also made a braided connection between the bus capacitor and the PCB.  There are three pairs of positive and negative bus wires that are braided together so that the counter-flowing currents flow along the nearly the same paths to/from the PCB.  When shorting the bus connection wires together, I measured about 100 nH of inductance.

Dan

11
Which interrupter are you using?  Since the note seems to be totally absent and not just muted, it looks to me like either the interrupter has some sort of limit set in the MIDI note it will play.  It is also possible that the MIDI file is set up incorrectly.  For the oneTesla interrupter that I use, for example, all notes must be channel 0 or they will not play, and if more than 2 notes are played at once, one of the two notes are stopped (it only has 2 note polyphony).  If you want to examine this the MidiEditor program is very handy:

https://www.midieditor.org/

I also attached some music that I adapted for the oneTesla interrupter if that's what you're using.

If you want, you can look at the DRSSTC PCB Pack I made

https://github.com/profdc9/DRSSTC-PCB-Pack

The "interrupter" project is a multiple function interrupter and includes the oneTesla MIDI interrupter on it if you want to build one yourself.  You will need an ATTINY85 and an AVR programmer.

Dan

12
Dual Resonant Solid State Tesla coils / Re: My first DRSSTC
« on: September 24, 2018, 05:39:01 PM »
Your GDTs look ok, they are probably ferrite toroids if they are black and have a high permeability 6000 to 9000.   I am not sure what kind, but it's probably ok as it is.  It can be a problem at the higher frequencies if the ferrite has too low of a bulk resisitivity.  You can tell this because you can take your multimeter and measure the resistance between two nearby points on the toroid perhaps a few mm apart and you will see that it reads in the 10 to 1000 kohm range.  Higher is better, but with MnZn usually higher permeability means low resistivity, so there's a compromise.   Really high permeability 8000-10000 is usually used for low frequency (<100 kHz) switching power supplies, while permeability 1000-3000 is used for medium frequencies (100 kHz to 1 MHz).  The 77 mix is good up to 1 MHz, but the permeability is lower than what you have, but if you are using CAT5 twisted pair the leakage inductance shouldn't be a problem.  At any rate, if it's working, don't mess with it.

Dan

Hi Dan,
Here is my GDT's. First CAT5, all bifilar winding but hi initial permeability iron core. (6000 to 9000) They all have similar results. I will also experiment with ferrite core on your suggestion

Now i have better result with phase lead. First image no phase lead, second with adjut phase lead.

Edit: image add attachments

13
It would be cool to take a USB protocol chip such as the FT232H and write some software for it so it would try to figure out what kind of protocol it is looking at and then you could connect to it using one of the many protocols it implements, UART, SPI, I2C, JTAG, etc.   Sort of a universal low speed protocol translator device.  A technique like this could be used to try to figure out what kind of signal and the data rate.

Dan

I found a small, embedded machine that I wanted to turn in to a small firewall. It's an x86-based industrial computer with 3xNIC and a 9 pin D-sub connector for console access. The OS  and applications are stored on a CF card and with the software I intend to use I needed to get the serial access going so I could make the initial configuration but no matter what baud rate I tried I could not get it to work. 1200 baud was the "best" but still only gibberish so I had to figure out a way to examine the signaling on the serial port and determine the actual baud rate from that. I found some web sites that explained how an oscilloscope could be used so I tried it. It worked OK but I wanted to get more data and also the signal so I connected the transmit pin to an optocoupler (through a constant current limiting device) and fed the signal to my logic analyzer. At first I tried the "auto baud rate function" and a lot of different settings but then I looked at the signals and looked for the "shortest time" or "highest frequency" which was 680Hz. Half of that time equals 1360 which is the baud rate that was used. After I figured that out I could decipher the information sent on the serial port and start configuring my device.

I thought this information could be useful to others.

14
Dual Resonant Solid State Tesla coils / Re: My first DRSSTC
« on: September 23, 2018, 11:11:05 PM »
What determines the number of turns is the impedance of the load.  At the frequency of use, the impedance of the coil must be greater than the load, so that the primary side coil should have an impedance much greater (3-4 X at least) as the driving impedance, and the secondary side should be much greater than the load impedance.  A IGBT or MOSFET gate is a capacitor and actually a fairly low impedance.  You can always increase the number of turns, assuring that the impedance of the coil is higher than the mosfet gate, but the leakage inductance increases as well.  A bifilar winding will make the leakage inductance very low and this should not be a problem.  Take two different color wires, twist them together, wind them together around the toroid perhaps 10 times, and then you have a 1:1 transformer with one color wire being the primary and the other the secondary.  It's very simple to do right once you have the right material.  Make sure the insulation on the wire is good for at least 600 volts, so sometimes teflon wires are used, because the insulation is thin reducing the leakage inductance, but maintains a high dielectric resistance. 

Dan

15
Dual Resonant Solid State Tesla coils / Re: My first DRSSTC
« on: September 23, 2018, 05:07:15 AM »
The gate driver transformer is typically bifilar wrapped around a ferrite core NOT an iron powder core (there's a difference).  T130-26 is a micrometals iron powder material typically used for power inductors with a permeability of 75.  It's designed to be a low-loss inductor, and is not as good as a transformer core.  Most MnZn ferrites are have permeability typically in the thousands.  A good toroid would be something like a FT82-77 should be sufficient.  It has a permeability over 2000 and is good up to a few MHz.  But there are many materials that would work, also a FT82-43, even though it has a permeability of only 850, is ok too.  And it must be wound bifilar to have good magnetic coupling between the primary and secondary turns.

Dan

16
Dual Resonant Solid State Tesla coils / Re: 4x QCW coils playing MIDI
« on: September 22, 2018, 04:09:50 AM »
Watching that video, I think the acoustics of that room helped the sound a lot.  It would probably have sounded much different if those coils were outside.  The echo effect really improves the staccato of the QCW coil and gives it more duration.

Dan

17
Dual Resonant Solid State Tesla coils / Re: My first DRSSTC
« on: September 22, 2018, 04:03:01 AM »
With the board I built that uses phase lead, without placing it in a metal box, and putting chokes on the transformers coming into the circuit board, the board was very susceptible to noise as it is placed right under the tesla coil.  I choked the power supply cable, the gate drive transformer, and the current sense transformers, and had an aluminum box around the circuit as well, though I could operate it with the top off when tuning with relatively low bus voltage.  You can make a simple choke by getting a ferrite toroid, twisting the two leads together, and wrapping the leads several times around the toroid.

The phase lead inductor coil I used was not shielded so it probably was picking up some magnetic field from the tesla coil itself, as it is basically behaves like a ferrite loopstick antenna similar to those used in AM radios.  This is one reason having a good metal box around the circuit is critical.

Dan

Hi Mads,
thank you for your reply and sorry for the double posting  :-[

Quote
Who made that red UD3.0 driver board? You mentioned UD2.5?
Me :)
based on ud 2.5, some minor placement changes, I've canceled the second output (fdd8424 and UCC's), I've added the IXYS IXDD430 gate drivers instead. (IXDDs have low voltage protection and its 30 amps)

Quote
The large spikes you are talking about is that on the inverter output or on the IGBT gates?
Inverter output
 
Quote
The phaselead UD's from 2.1 and up are however much more sensitive to excessive energy in the system and therefore it is often needed to have a 1-2K power resistor across the inverter output to remove any residual charge that will ruin the oscillation feedback.

Hmm... I've tried it and have a better waveform :)
maybe it's because I went from cola to beer :))

18
I would consider using the STM32F103Rx series if there was a convenient, cheap board like the bluepill you could buy.  The bluepill is $3 on ebay.  It's still much cheaper to use that and a MCP4921 (1.25 USD) than almost any other dev board.  The tinnitus32 theremin (https://github.com/gerdb/tinnitus32) - by the way this is an AWFUL name for a device that is supposed to sound pleasant - uses the STM32F4 but isn't terribly convenient because it doesn't really have a PCB to integrate everything into, though such a thing is possible for the STM32 discovery board.  A form factor like the bluepill or Arduino Nano is very convenient for integrating into projects unlike a whole dev board, though a dev board could be integrated into a project like the OpenTheremin does.

Dan


19
Dual Resonant Solid State Tesla coils / Re: Drsstc 3
« on: September 16, 2018, 04:34:36 AM »
Nice work populating the board.   Just make sure you put heatsinks on the voltage regulators, or they will overheat.  Let us know how it goes.  You can even try the ud29 board if you want to try skip pulse.   It's almost the same board, but with only a handful of extra components.

BTW I put the DRSSTC PCB pack up on github

https://github.com/profdc9/DRSSTC-PCB-Pack

Enjoy,

Dan

20
Hello,

I made a theremin based on a STM32 microcontroller (the $3 bluepill).  You can see me play it in this video

/>
The theremin as you can see is quite sensitive.  I actually put a fiber optic output on the board so I can program it to be an interrupter for a DRSSTC.

The parts are very inexpensive and the circuit is fairly simple.  The PCB, schematics, and the software are on a github

https://github.com/profdc9/MCTheremin

If you want to try to build it let me know.  Enjoy!

Dan



Pages: [1] 2 3 ... 10

* Recent Topics and Posts

post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
Today at 08:08:58 AM
post Re: How to calculate VA rating and other things for Ferrite Core? (SMPS)
[Transformer (ferrite core)]
sjsimmo
Today at 01:24:15 AM
post How to calculate VA rating and other things for Ferrite Core? (SMPS)
[Transformer (ferrite core)]
FilipŠebík
January 18, 2019, 07:32:38 PM
post Re: How to design a 7.5kV AC source?
[Transformer (ferrite core)]
profdc9
January 18, 2019, 04:25:14 PM
post How to design a 7.5kV AC source?
[Transformer (ferrite core)]
CristianM
January 18, 2019, 03:48:06 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
the_anomaly
January 17, 2019, 02:01:36 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
January 16, 2019, 04:26:38 AM
post AC vs DC fuses, high current, explosive destructive testing and theory
[Capacitor banks]
Mads Barnkob
January 15, 2019, 09:48:48 PM
post Re: My X-Ray Machine
[X-ray]
neukyhm
January 15, 2019, 10:51:46 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
January 14, 2019, 05:08:38 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
the_anomaly
January 14, 2019, 01:15:53 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
Mads Barnkob
January 14, 2019, 12:22:07 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
January 11, 2019, 05:10:39 AM
post Re: My X-Ray Machine
[X-ray]
Max
January 10, 2019, 10:59:25 PM
post Re: 迎词、来
[General chatting]
profdc9
January 10, 2019, 06:56:59 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
January 10, 2019, 05:33:48 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
black.yang
January 10, 2019, 02:11:58 AM
post Re: My X-Ray Machine
[X-ray]
Mads Barnkob
January 09, 2019, 09:14:59 PM
post Acoustic spectra of sung vowels by the FFT analyzer HP 3561A
[Electronic circuits]
Physikfan
January 08, 2019, 08:44:16 PM
post Re: IGBT failure in DRSSTC
[Dual Resonant Solid State Tesla coils]
Felix Bieri
January 08, 2019, 05:33:55 PM
post Re: Huawei RRU3928 1800MHz radio base station teardown (part 1 of 2)
[Radio frequency]
Mads Barnkob
January 08, 2019, 08:25:08 AM
post Re: SimpleDriver v2.3, my phase-shifting QCW DRSSTC controller
[Dual Resonant Solid State Tesla coils]
flyglas
January 08, 2019, 08:25:02 AM
post Re: SimpleDriver v2.3, my phase-shifting QCW DRSSTC controller
[Dual Resonant Solid State Tesla coils]
Hydron
January 08, 2019, 02:01:50 AM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Hydron
January 07, 2019, 10:23:38 PM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Laci
January 07, 2019, 08:53:32 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
January 07, 2019, 08:17:44 PM
post Re: SimpleDriver v2.3, my phase-shifting QCW DRSSTC controller
[Dual Resonant Solid State Tesla coils]
Netzpfuscher
January 07, 2019, 07:37:53 PM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Uspring
January 07, 2019, 01:30:36 PM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Laci
January 07, 2019, 12:43:26 PM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Hydron
January 07, 2019, 08:09:49 AM
post Re: SimpleDriver v2.3, my phase-shifting QCW DRSSTC controller
[Dual Resonant Solid State Tesla coils]
NEYi
January 07, 2019, 07:43:50 AM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
Mads Barnkob
January 07, 2019, 06:48:06 AM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
January 07, 2019, 06:39:56 AM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Laci
January 06, 2019, 09:23:19 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
January 06, 2019, 07:11:25 PM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Uspring
January 06, 2019, 07:02:14 PM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
flyglas
January 06, 2019, 12:43:46 PM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Laci
January 06, 2019, 11:55:09 AM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
TDAF
January 06, 2019, 09:48:06 AM
post Re: First SSTC build, need help troubleshooting
[Solid state Tesla coils]
TDAF
January 06, 2019, 09:45:17 AM
post 关于: 这个便宜的 drsstc 驱动程序从 aliexpress 1.3 b 类型?
[Dual Resonant Solid State Tesla coils]
black.yang
January 06, 2019, 08:34:46 AM
post 迎词、来
[General chatting]
black.yang
January 06, 2019, 08:20:21 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
flyrod
January 06, 2019, 12:34:15 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
January 05, 2019, 05:27:23 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
flyrod
January 05, 2019, 03:46:29 PM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Laci
January 05, 2019, 09:51:10 AM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
January 04, 2019, 11:02:25 PM
post Re: (DR)SSTC II
[Dual Resonant Solid State Tesla coils]
Laci
January 03, 2019, 08:38:15 PM
post Re: SimpleDriver v2.3, my phase-shifting QCW DRSSTC controller
[Dual Resonant Solid State Tesla coils]
flyglas
January 03, 2019, 08:15:48 PM
post Re: Component questions
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
January 03, 2019, 02:05:31 PM