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DRSSTC Simulation

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Goodchild

Thu Aug 04 2011, 06:09AM

Registered Member #2292 Joined: Fri Aug 14 2009, 05:33PM
Location: The Wild West AKA Arizona
Posts: 795

Well this isn't a new topic but it's not one I've seen for a long long time. DRSSTC simulation.

I wanted to start this thread to gather any tips tricks hints ect... on the topic.

I have been working on my own general simulation in LT spice. So far modeling the primary circuit was not bad at all. With no secondary in the system, it reacts and behaves just like a normal DRSSTC with no secondary would.

For my second experiment I "attempted" to add a secondary circuit that incorporated some simple streamer loading into the output as to load down the primary circuit. For this I used the Terry Fritz model of 220k 5p per foot. This seems to have "ok" results but I'm looking to improve upon it.

This brings me to you guys, the vast community of Tesla coil builders. Any ideas are welcome I'm just looking to shed some light on the dark art of Tesla coil simulation.

Here is my model working with the Terry Fritz streamer model in LT spice:
6006308279 634d430c4e Z

Bigger photo here:

I have also attached my LT spice models one with just the primary and the other with the Terry model and primary model.

Goodchild

Thu Aug 04 2011, 06:11AM

Registered Member #2292 Joined: Fri Aug 14 2009, 05:33PM
Location: The Wild West AKA Arizona
Posts: 795

woops sorry for the double post forgot to add the simulations!
]drsstc_lt_spice_models.zip[/file]

Harry Dellamano

Tue Aug 09 2011, 12:02AM

Registered Member #4051 Joined: Mon Aug 08 2011, 11:18PM
Location: Camarillo Ca. 93012
Posts: 2

Interesting,
In a DRTC is there not two operating resonant frequenies, FH, FL given they are tuned initially to Fo? At which frequency does this simulation opperate?

Cheers
TD2K

Goodchild

Tue Aug 09 2011, 12:29AM

Registered Member #2292 Joined: Fri Aug 14 2009, 05:33PM
Location: The Wild West AKA Arizona
Posts: 795

Harry Dellamano wrote ...

Interesting,
In a DRTC is there not two operating resonant frequenies, FH, FL given they are tuned initially to Fo? At which frequency does this simulation opperate?

Cheers
TD2K

The simulation uses a primary feedback setup like used in most DRs. With this being said it basically latches onto the strongest pole and oscillates at that frequency.

Harry Dellamano

Tue Aug 09 2011, 02:53AM

Registered Member #4051 Joined: Mon Aug 08 2011, 11:18PM
Location: Camarillo Ca. 93012
Posts: 2

Looks like Fos=111.6KHz, Fop=108KHz and FH=120.8KHz which should be the operating frequency. You could improve the gain by as much as 2dB by lowering C1 from 17.05nF to 15nf and delaying the switching to a more optium point.

dude_500

Tue Aug 09 2011, 03:33AM

Registered Member #2288 Joined: Wed Aug 12 2009, 10:42PM
Location: Cambridge, MA
Posts: 179

I made an animation of the tuning of the coil using this simulation, can be seen here:

Finn Hammer

Tue Aug 09 2011, 05:20AM

Registered Member #205 Joined: Sat Feb 18 2006, 11:59AM
Location: SkÃ¸rping, Denmark
Posts: 741

Scaled on the Y-Axis that animation looks a lot like the scopeshot of a realtime tuning I did on the DRASTIC Thumper about a year ago

Cheers, Finn Hammer

Goodchild

Tue Aug 09 2011, 07:05AM

Registered Member #2292 Joined: Fri Aug 14 2009, 05:33PM
Location: The Wild West AKA Arizona
Posts: 795

Looks like Fos=111.6KHz, Fop=108KHz and FH=120.8KHz which should be the operating frequency. You could improve the gain by as much as 2dB by lowering C1 from 17.05nF to 15nf and delaying the switching to a more optium point.

The primary tank values and secondary values for that simulation were pulled right off of Terry's web site just to try out his model in this simulation. His model was based off of his SGTC so it may not seem exactly like a DRSSTC waveform.

I have done some more simulations using my large DRSSTC as a model for my latest simulation and the results are astoundingly similar to the real thing! Terry's spark model of 220k + 1p/foot stopped being linear at about 6 feet of spark. I had to add much more capacitance to match the real world primary current shape and amplitude. This is a simulation with the coil pushing sparks in the 10 to 11 foot range.

6024532941 41173cdcc3 Z

Larger image here:

I plan to make a new spark model that uses voltage controlled switches to slowly add capacitance as the top voltage grows. Hopefully this with be a bit more accurate than the current model I'm using.

dude_500 AWESOME! I very much liked your video of the tuning, that is exactly the kinda stuff I was looking for when I start this thread!

have also attached the LT spice simulation for anyone that would like to use it.
]drsstc_5_lts.zip[/file]

dannybeckett

Thu Oct 03 2019, 02:47PM

Registered Member #3300 Joined: Sat Oct 09 2010, 11:57PM
Location:
Posts: 8

I would like to try this simulation but unfortunately the file does not appear to be available?

Terry Fritz

Wed Dec 11 2019, 06:09AM

Registered Member #393 Joined: Tue Apr 18 2006, 12:30AM
Location:
Posts: 297

" I used the Terry Fritz model of 220k 5p per foot."

I am a bit stunned to know that simulation still stands to this day!

But what works, just works...

Terry

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