What is BPS?

[PEDRO HENRIQUE]

I'm reading a guide about DRSSTC, and in the guide the term BPS appeared, but I don't know what this means.
Someone know what means BPS (in DRSSTC topic)?

[AstRii]

It stands for "Bangs Per Second", it's the rate at which the coil fires streamers (Count of enable pulses per second).

[PEDRO HENRIQUE]

So, if I want to build a musical DRSSTC, will I have to change the BPS?

[alan sailer]

Pedro,

I am not sure exactly what your question is but I can try to answer.

All the tesla coils I have read about or built oscillate at frequencies much higher than you can hear. So in order to
make a tesla coil play a note you have to turn the coil on and off. This is done with an interrupter.

If the interrupter turns the telsa coil on and off at 200 beats per second then you will hear a 200Hz sound. And so
it goes for any other pulse rate. The term BPS can stand for bangs per second, but as far as I can tell, beats per second is
the same thing. Or cycles per second. Or hertz.

So if you want to get a tesla coil to play music you have to have an interrupter that can drive the tesla coil at various beats per second.

For example "Mary Had a Little Lamb" is made of three notes C, D and E. C is 261.6 BPS, D is 293.6 and E is 329.6. If you use your
musical interrupter to play these three BPS (or notes) in the right order you will get "Mary Had a Little Lamb".

Once again please remember that the coil is actually oscillating at much higher frequency. But you can't hear that. So you turn the
coil on and off at lower (audio) frequencies that you can hear. Then the coil can play music.

Cheers.

[PEDRO HENRIQUE]

If the interrupter turns the telsa coil on and off at 200 beats per second then you will hear a 200Hz sound. And so
it goes for any other pulse rate. The term BPS can stand for bangs per second, but as far as I can tell, beats per second is
the same thing. Or cycles per second. Or hertz.

So if you want to get a tesla coil to play music you have to have an interrupter that can drive the tesla coil at various beats per second.

For example "Mary Had a Little Lamb" is made of three notes C, D and E. C is 261.6 BPS, D is 293.6 and E is 329.6. If you use your
musical interrupter to play these three BPS (or notes) in the right order you will get "Mary Had a Little Lamb".

This is exactly what I want to know, but I have other question.

What is the max BPS and minimum BPS I can use in the DRSSTC?, because we can listen from 20 to 20kHz, therefore to play all songs thr DRSSTC have withstand from 20BPS to 20kBPS.

Am I right?

[Mads Barnkob]

The BPS is one of the vital user input parameters that can damage a DRSSTC. What is most important is that you do not violate the maximum pulse temperature of your IGBTs, they will go BOOM if you do (too much). The other vital user input is the maximum on-time. These two parameters are controlled differently by a MIDI interrupter for playing music. The MIDI file contains the information about which note to paly (BPS/Hz) and the interrupter should have a control over maximum permissible on-time, like 300uS per note.

I am not sure if you are referring to my DRSSTC guide, but here is a FAQ that answers some of the questions: https://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/drsstc-faq-frequently-asked-questions/ (though I do see that I should update the FAQ )

Once you have calculated the highest possible peak current in your primary circuit (help for that here: http://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/igbts/ ) you can play around with the MMC calculator to see how higher BPS/on-time affects your IGBT and MMC: https://kaizerpowerelectronics.dk/calculators/mmc-calculator/

If all this is way too much new information, just use the examples in the drop down menus of my DRSSTCs. The Kaizer DRSSTC1 is good example of a medium sized coil that everyone (almost) has the tools/room to build and run. Use that as an example and know that I did blow up the 60N60 bridge one time, so over-engineering in this hobby is never a bad thing

[MRMILSTAR]

BPS has been thoroughly explained. Your concern about a frequency range of up to 20 khz is pointless. The music played with transistor tesla coils is full of harmonics and other distortion. You are essentially listening to a series of square wave pulses. The fundamental frequency dominates so you can play music on them and recognize the tune. Just don't expect any sort of high fidelity sound. If you want high fidelity sound, go into your living room and listen to a CD on your stereo equipment.

[GrantV]

BPS has been thoroughly explained. Your concern about a frequency range of up to 20 khz is pointless. The music played with transistor tesla coils is full of harmonics and other distortion. You are essentially listening to a series of square wave pulses. The fundamental frequency dominates so you can play music on them and recognize the tune. Just don't expect any sort of high fidelity sound. If you want high fidelity sound, go into your living room and listen to a CD on your stereo equipment.

Good grief Steve, that's a little rough isn't it!

Stay on topic and at the very least point him in the direction of a CW SSTC or maybe a class E ....

BUT REALLY ... sending anyone off the beaten track to old skool nonsense like a CD player on a HIFI is just bang out of order 

[SalinsLV]

This is exactly what I want to know, but I have other question.

What is the max BPS and minimum BPS I can use in the DRSSTC?, because we can listen from 20 to 20kHz, therefore to play all songs thr DRSSTC have withstand from 20BPS to 20kBPS.

Am I right?

20KBPS would stress regular DRSSTC a lot. Even 50BPS + 100 caused problems for my SSTC. If You want to listen to regular music coming from the plasma, i suggest building HFSSTC.

[alan sailer]

SalinsLV,

It seems like you are kind of caught up in theory. A perfect human hearing range is 20 to 20KHz. But basically no
one who lives in a modern industrial (noisy) society has this hearing range. And no DRSSTC will be able to play
tones in that entire range.

Your question, "What is the max BPS and minimum BPS I can use in the DRSSTC?" is a simple question that has
no easy answer. All DRSSTCs have limitations (current, voltage, thermal etc) and learning about those limitations
(usually by killing transistors) is not a simple process.

I agree with Mads recommendation to look into his DRSSTC pages. There are a lot of questions that can be answered
by reading and calculating with what he has supplied.

In addition maybe watch a couple of musical DRSSTC videos and listen carefully. You will not hear any massive bass
notes.  A DRSSTC is not a good musical instrument, the notes are very metallic and of limited frequency range. You
will not be able to get a DRSSTC to play either end of the theoretical hearing range you are worried about.

Cheers..

[MRMILSTAR]

BPS has been thoroughly explained. Your concern about a frequency range of up to 20 khz is pointless. The music played with transistor tesla coils is full of harmonics and other distortion. You are essentially listening to a series of square wave pulses. The fundamental frequency dominates so you can play music on them and recognize the tune. Just don't expect any sort of high fidelity sound. If you want high fidelity sound, go into your living room and listen to a CD on your stereo equipment.

Good grief Steve, that's a little rough isn't it!

Stay on topic and at the very least point him in the direction of a CW SSTC or maybe a class E ....

BUT REALLY ... sending anyone off the beaten track to old skool nonsense like a CD player on a HIFI is just bang out of order 

He was asking about frequency response to 20 khz which is at the upper limit of human hearing. This implies an expectation of high fidelity sound from a Tesla coil. If this is indeed the case I informed him that his expectation was unrealistic and why. I rarely use CDs but even though they are "old skool" as you say, they are still the highest fidelity form of music playback technology available to the average consumer. If the idea of an optical disc bothers you does FLAC technology with flash drive storage comport with your vision of modern high fidelity playback? If not, then what? Either CD or FLAC technology provides the same sound quality.

I don't know and you don't  know what his expectation of sound quality is from a Tesla coil. It all sounds perfectly on-topic to me.

[Mads Barnkob]

Lets try to keep a focus on the question about DRSSTC thermal capabilities seen from a "audio" modulating point of view.

[GrantV]

He was asking about frequency response to 20 khz which is at the upper limit of human hearing. This implies an expectation of high fidelity sound from a Tesla coil. If this is indeed the case I informed him that his expectation was unrealistic and why. I rarely use CDs but even though they are "old skool" as you say, they are still the highest fidelity form of music playback technology available to the average consumer. If the idea of an optical disc bothers you does FLAC technology with flash drive storage comport with your vision of modern high fidelity playback? If not, then what? Either CD or FLAC technology provides the same sound quality.

I don't know and you don't  know what his expectation of sound quality is from a Tesla coil. It all sounds perfectly on-topic to me.

Hi Steve,

LOL I am sorry if you missed the  at the end, I was hoping my comment would come across as humorous and was absolutely not intended as a slight :-)

[PEDRO HENRIQUE]

BPS has been thoroughly explained. Your concern about a frequency range of up to 20 khz is pointless. The music played with transistor tesla coils is full of harmonics and other distortion. You are essentially listening to a series of square wave pulses. The fundamental frequency dominates so you can play music on them and recognize the tune. Just don't expect any sort of high fidelity sound. If you want high fidelity sound, go into your living room and listen to a CD on your stereo equipment.

Hello, first i want to apologize because i've been too busy, and I wasn't able to give attention to this post, now let's to the topic.

Sorry if I let you understand that I wanted high-fidelity audio, I just want to build a DRSSTC, and I want to understand all the limitations of a DRSSTC, and how I will play music.
Now I want to know how I'm going to convert a song into playable audio to DRSSTC, if you can explain to me I'll be grateful.

I have other questions, but where I live, now is too late, I'll post then tomorrow, thank you for the patience.

[Mads Barnkob]

BPS has been thoroughly explained. Your concern about a frequency range of up to 20 khz is pointless. The music played with transistor tesla coils is full of harmonics and other distortion. You are essentially listening to a series of square wave pulses. The fundamental frequency dominates so you can play music on them and recognize the tune. Just don't expect any sort of high fidelity sound. If you want high fidelity sound, go into your living room and listen to a CD on your stereo equipment.

Hello, first i want to apologize because i've been too busy, and I wasn't able to give attention to this post, now let's to the topic.

Sorry if I let you understand that I wanted high-fidelity audio, I just want to build a DRSSTC, and I want to understand all the limitations of a DRSSTC, and how I will play music.
Now I want to know how I'm going to convert a song into playable audio to DRSSTC, if you can explain to me I'll be grateful.

I have other questions, but where I live, now is too late, I'll post then tomorrow, thank you for the patience.

How audio is converted into a square wave signal is explained in this article on a hardware based midi interrupter by ctc-labs.de https://kaizerpowerelectronics.dk/tesla-coils/musical-sstcdrsstc-interrupter/ the same principles applies to the software based interrupters, they just implement it with lookup tables or other ways of converting a MIDI digital data stream, instead of a analog audio signal.

[Felix B.]

Well you probably already know that most DRSSTCs are controlled by a Fiber optic cable. If you send in a short let's say 100us pulse of light there will be a pulse of lightning. If you now send for example 440 pulses per second you can play a 440Hz tone. Most musical interrupters work with MIDI which is in my opinion the best solution because you dont have a messy analog signal. I hope that cleared up the confusion.

[PEDRO HENRIQUE]

Hello, i was out of the forum because my pc had broken down, and i had to buy a part that took too long to arrive.

So my first question is: what is the best BPS range for the tesla coil to play music (I was thinking something like 100BPS to 400BPS)?

I'll ask more questions as these are answered, because I don't fill up with questions.

thanks you for the patience.

[Mads Barnkob]

Hello, i was out of the forum because my pc had broken down, and i had to buy a part that took too long to arrive.

So my first question is: what is the best BPS range for the tesla coil to play music (I was thinking something like 100BPS to 400BPS)?

I'll ask more questions as these are answered, because I don't fill up with questions.

thanks you for the patience.

The question does not make sense. There is no best BPS, the BPS or Hz is just the frequency of your interrupter signal.

You can design your coil to withstand higher BPS/Hz, by designing it to withstand higher RMS current and better thermal handling.

[PEDRO HENRIQUE]

The question does not make sense. There is no best BPS, the BPS or Hz is just the frequency of your interrupter signal.

You can design your coil to withstand higher BPS/Hz, by designing it to withstand higher RMS current and better thermal handling.

Hello Mads.

That's not what I meant.

I want to know a sufficient BPS range to a very large tesla coil play music like the coils on youtube.

Examples:

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I want my tesla coil to play music like these.

[alan sailer]

Pedro,

I'd like to point out that these coils are like meters high? So they will sound different than a small coil.

The analogy isn't great, but a piccolo sounds way different than a bassoon.

I have a tiny coil (10cm) that sounds like an angry wasp. And a larger mini coil (100cm) that sounds much more
impressive.

And both are playing the same MIDI file.

Cheers.