Tesla Coil Show Controller – 6 Interrupters (Part 4 of 8)

In this video I build 6 Tesla coil interrupters with selector switches, normal and burst mode. There is also a seventh master interrupter to control …

6 Channel DRSSTC Show Controller

This project is about building a Tesla coil show controller that can control up to 6 Tesla coils at once. It will all be housed in a transportable 19″ rack mount flight case for ease of transportation and to protect the electronics. It will feature individual interrupters, touch screen controlled MIDI interrupter, safety features to ensure a safe method of working with the Tesla coils before a show, under a show and after a show.

The 6 channel MIDI interrupter is the feature-rich Syntherrupter. Made by Max as he shares all the plans, documentation, code and schematics.

The normal DRSSTC interrupters with additional audio input is a free and open design made by Dan / Profdc9, you can download the schematics and gerber files to order the PCB boards for yourself.

The above layout is my initial idea of how I would place the different features, with a high focus on ergonomics for the most used parts like interrupters and a high focus on safety, so that pushing anything by accident is limited to a minimum. This is a rather big project and a lot of the detailed design is first done at each stage. I have split the project into the following 8 parts.

Part 1 – The parts
Part 2 – Programming Syntherrupter
Part 3 – 6 optical outputs build
Part 4 – Interrupters
Part 5 – Syntherrupter and MIDI
Part 6 – Audio input panel
Part 7 – Safety panel
Part 8 – Power supply

Part 1 – The parts

I bought a 19″ transportation rack, empty panels and power bar from the German company Adam Hall. A supplier to many smaller retailing companies of disco, event and show business equipment like audio, light and transportation gear. In this video I go through unpacking and unboxing of all the parts and walk through the initial layouts.

Part 2 – Programming Syntherrupter

In part 2 I go through features of the syntherrupter, firmware flashing, microcontroller / display programming and test of the Tiva development board and Nextion display. Max wrote an extensive and very good documentation on setup, programming and all features.

Having the “Intelligence” version of the Nextion display did result in some issues. For some reason Nextion decided that a more powerful version of their display should have a whole range of new properties on screen elements and not interpret a project file the same way that the basic / enhanced versions does… Some of the missing graphics was fixed by copying links to graphics to an additional configuration field called pic1, but the way nightmode is made, it was not possible to get the right graphics for that. Max has since this video was recorded released a new Nextion display software version, that will be shown in a later video. This also includes new functionality support for the “Intelligence” version of the Nextion display.

I tested the output from the Syntherrupter, through a optical output circuit and into the driver of a DRSSTC. The results are described on the individual oscilloscope screenshots, but it really shows nothing out of the ordinary. Its a good sturdy drive with good rise and fall times, only worth noting is the 3 uS delay in turn-off caused by the total delay from Syntherrupter to optical input in the driver.

Part 3 – 6 optical outputs build

The single output that was tested in part 2 is made into a complete set of 6 optical outputs in a panel with switches for selecting different interrupters, indication LEDs and dry test speakers. The panel features for each of the 6 channels:

  • Optical output transmitter IF-E96E, 1mm plastic fiber
  • Output LED indicator
  • Switch to turn on/off optical output transmitter
  • Switch to select between two different interrupters
  • Switch to turn on/off dry test speaker
  • Dry test speaker

I wanted everything on one PCB for the outputs, like switches and wires for all. Luckily I still have a lot of color-coded multi conductor cable that I cut up to use the single wires. Makes it very easy to work with large wire bundles and quickly identidy or make some identical.

Download Schematic and download PCB layout. Schematics are made in https://www.expresspcb.com/pcb-cad-software/ which is just an old habit of mine for creating real fast schematics and PCB layouts, when I etch the PCBs myself.

Part 4 – Interrupters

6 regular DRSSTC interrupters are build from the free and open designs from Dan / Profdc9 on highvoltageforum.net.

Download layout drawings. Drawings are made with the free draw.io software, which can be used both online and a downloadble dekstop application.

I built 7 interrupters, one for each channel and a master interrupter, that by a switch, can take over any channel. Each channel can also switch between normal and burst mode.

The interrupter also has a “sound” input option, which can take any kind of regular audio output and transform it into a on-time limited square-wave signal. This feature is first implemented in another part, as this panel could not fit anymore control inputs.

Using the color coded wires, it was easy to keep track of the hundreds of wires. Each interrupter repeats the individual colors I used for the output panel channels, but also for the interrupter itself it uses identical colored wires for each interrupters control inputs. This way its easy to distinguish each channel, but also rule out any faults as all channels looks identical.

Example – Changed the Way You Kiss Me, on a Musical Tesla Coil

“Changed the Way You Kiss Me” is a song by British singer Example from his third studio album, Playing in the Shadows. MIDI/Music interrupters you can build yourself:4 …

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The “Dance of the Sugar Plum Fairy” is a dance for a ballerina. It is the third movement in The Nutcracker pas de deux. This pas de …

Tesla Coil Show Controller – 6 Outputs Build (Part 3 of 6)

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Tesla Coil Show Controller – Programming Syntherrupter (Part 2 of 6)

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Tesla Coil Show Controller Project (Part 1 of 6)

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How To Build Flight Case and Transport Box

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Jingle Bells, on a Musical Tesla Coil

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Rudolph the Red-Nosed Reindeer, on a Musical Tesla Coil

Rudolph the Red-Nosed Reindeer, played on my own musical Tesla Coil, the Kaizer DRSSTC 2 Tesla Coil using the USB MIDI Stick interrupter. MIDI/Music interrupters …

Universal Driver 2.1b

Some of this content is originally created by Steve Ward (stevehv.4hv.org) and is re-posted with his permission.

Steve Wards work with phase lead compensated drivers is most likely based off the work that Finn Hammer did on his driver modifications called the “Prediktor” that was a DRSSTC driver with phase lead.

The content of the folder stevehv.4hv.org/stevehv/lead_comp/ did not contain much written information, except the quotes below here with some details on the circuit. The pictures are from Steve, but the descriptions of them is the interpretation of Mads Barnkob.

It is recommended to read the article on the Universal Driver 1.3b to understand how the driver works and the changes from 1.3b to 2.1b will not seem to radical afterwards.

26th October 2009

Steve Ward built and tested the universal driver 2 with phase lead on his “DRSSTC Magnifier – Mark I” Created 4/15/05: http://www.stevehv.4hv.org/DRSSTCmag1.htm

The first tests was done on an unknown IGBT, and not the magnifier system above. Green is primary circuit current and light blue is inverter output voltage. Yellow is presumably gate drive signal.

For the tests that are known to be done on a CM300 IGBT brick, on the magnifier system, the following collection of oscilloscope screenshots was available. Green is primary circuit current and yellow is inverter output voltage.

26th March 2011

R26 added in series with C33 because when it was only C33 the peak voltage of the positive feedback (hysteresis)
was outside the save range for the comparator inputs. R26 and C33 provide short positive feedback pulses which helps keep the comparator from self-oscillating.

R27 added across C5: There seemed to be some instability in start up, sometimes the TL3116 would start off with
output HI, sometimes output LOW. R27 restores proper bias to the comparator input by discharging the DC offset that may be left across C5. I picked 100k for R27, but perhaps values as low as 10K may be required, i would not suggest going lower than 10k.

Steve Ward, 26th March 2011

The files for the quoted text above is the old files called UD2_1 and is listed at the bottom of this article.

2nd September 2012

You need EAGLE by Cadsoft (google it) to look at the board and schematic. You can get a free version on the web.

This project was created before i knew the importance of linking a schematic and board file. These files are not linked, consequently errors do happen!

I changed some biasing resistors for the phase lead comparator, if you have referenced the older versions you might notice this.

Im not sure the parts list is 100% up to date, i had to make some mods to the design after i ordered everything.

C33 controls a “no switch” time after each output transition on the comparator. Originally i found C33 could be just 220pF, but recently using CM600DU-24NF modules with a loooong 1uS or so delay in switching, i found i had to boost C33 up to 2.2nF.
This provided a longer period where the comparator has high immunity to noise, and without this there was severe “glitching” where the IGBT switch noise caused the comparator to switch several times instead of once per half-cycle.

R11 R12 and C9 with IC4E form a pulse-width limiter that is frequency dependent. You can disable it by shorting out C9.

Steve Ward, 2nd September 2012

The files for the quoted text above is UD2_1revb files, which are the latest and those that you should use!

1st May 2013

This is pictures of a finished universal driver 2.1b as I made it for my own large Tesla coil called Kaizer DRSSTC 3.

Freewheeling driver

The /leadcomp/ folder also contained a folder called /UD freewheeling driver/ which contained schematic, PCB layout, Atmel microcontroller code and gerber files for a freewheeling driver add-on

Old files that should not be used, only listed for historical reference

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Weezer – Buddy Holly, played on my own musical Tesla Coil, the DRSSTC2 Tesla Coil http://kaizerpowerelectronics.dk/tesla-coils/kaizer-drsstc-ii/ using the USB MIDI Stick interrupter: https://highvoltageforum.net/index.php?topic=1117.0 MIDI/Music interrupters …

Musical Tesla Coil with Tmax USB MIDI Stick

TMAX YouTube: https://www.youtube.com/channel/UCjzHB0f_nxv_XY8Z9P1BklQ TMAX website: https://tmax-electronics.de/projects/ GitHub: https://github.com/TMaxElectronics Not a paid promotion! I bought these from my own money. 1-2 channel Compact USB MIDI Stick: …

Grieg – In the Hall of the Mountain King, on a Musical Tesla Coil

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Portal – Still Alive, on a Musical Tesla Coil

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