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23rd July 2022

Interrupter

Introduction

Roughly a year ago I created quite a nice build of Syntherrupter, a very powerful interrupter designed by Max from HighVoltageForum.

This interrupter is designed for up to 6 Tesla coils and it features all the great functions like polyphonic outputs, active duty cycle limiter and real time MIDI decoding. I have bought a handy little case to which I installed all the components; display, microprocessor board, optical outputs, etc... Needless to say I was very satisfied with the final looks.

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img.1. - My first version Interrupter build

It looks professional and high quality. I also got told that it looks like a control panel for an atomic bomb launch on many occasions so I'm very pleased with the build, but it has multiple problems. The first design mistake was that my UI is reversed (optical outputs goes from right to left and manuals for them go from left to right). Another design mistake is that the display section with optical outputs has to be titled a bit so it fits to the case due to a tiny miscalculation. But all of those are just design flaws which I easily got used to, however there is one fundamental problem with this build; wiring. 

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img.2. - Inside of my Interrupter build

The wiring is a mess. A mess of thin wires with no cable management. Being messy is not a big deal as long as the wiring is hidden inside the box but the problem with this setup is that those wires can disconnect easily or just get loose which induces many problems. I have never had any issues with it but lately I was traveling a lot with my DRSSTC II and during driving the interrupter got quite the beating. When I arrived at the spot of "Astro assembly 2022" where I was to preform, during testing I noticed that the LEDs which indicate the outputs of the interrupter were not lighting up. Fortunately only the LEDs were malfunctioning, the optical outputs were all fine. Anyway what is the point of indication LED if it doesn't indicate:) I could quite easily solve this problem with re-soldering all the loose wires, but that solution is only temporary, I need much sturdier and reliable solution. I need to get rid of all those wires and rely on solid connections like copper traces on PCB. And that's exactly what I designed.. The almost exact same setup, but this time on a giant PCB.

 

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img.3. - New Interrupter schematics

img.4. - New Interrupter PCB design

img.5. - New Interrupter PCB model render

This PCB contains everything; battery holders, Li-Ion charger modules, boost converter modules, MIDI input, 2x USB input,... Everything on a single PCB. Much better setup, much less wiring and much more reliable solution.

The interrupter comes with quite high price tag:

PCB manufacture + shipping - 80$

Nextion display - 95$

Tiva microprocessor kit - 33$ 

6x Optical transmitter - 182$

5x Battery holder - 8$

5x Li-Ion 2600mAh battery - 38$

4x Li-Ion charger module - 9$

4x Boost converter module - 5$

This results in 449$ and it does not include the price for all the components and 3D printing a case.

It's roughly 100$ more than my previous build because of the PCB and the battery holders.

Not cheap but I'm quite sure that this is a permanent interrupter build which won't need any upgrades or revisions for a long time.

For now I do not have all the components needed, for example I don't need 6 optical transmitters when I only use it for maximum of 3 coils. And currently I only have 4 Li-Ion batteries. Nevertheless I started building the thing:

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img.6. - New Interrupter first boot

img.7. - New Interrupter testing output

So far I'm very excited of this build, it looks quite nice and it will allow me to travel around with my coils without needing to worry about loose wires. Of course, there will still be some things which will need wiring but much fewer and much shorter wires will be needed. The most important thing is that there are absolutely no wires from the output of the microprocessor up to the optical transmitter; it's all copper solid copper traces on a PCB.

For now I have nothing else to add, as I'm still waiting for some components to arrive, but the build looks promising.