SSTC=Super Simple Tesla Coil?
Dr. Dark Current, Sun Mar 26 2006, 08:09PMI had this idea in mind for long time: How about using that "dimmer circuit" to drive a TC primary? Maybe you'll have to use a fast triac and high number turns on secondary, but thats still simpler than building a complicated SSTC driver or designing a high voltage tank circuit for a SGTC. I'll try to build one soon and see how it performs.
Any ideas if it should work and how? My goal is to produce the highest voltage the simplest way, so even if it would be inefficient and bad performing compared to a "standard" TC, as long as it produces higher voltages than flyback it is great. Has anyone tried that before?
J.M.
Re: SSTC=Super Simple Tesla Coil?
Marko, Sun Mar 26 2006, 08:22PM
DImmer works by chopping parts of each halfwave by triac and you get no higher frequency than 50Hz, just a bit ''deformed'.
Some use PWM ICs for control but they also put out too low frequency and uselles waveform.
Driving any kind of TC with light dimmer makes no sense.
Marko, Sun Mar 26 2006, 08:22PM
DImmer works by chopping parts of each halfwave by triac and you get no higher frequency than 50Hz, just a bit ''deformed'.
Some use PWM ICs for control but they also put out too low frequency and uselles waveform.
Driving any kind of TC with light dimmer makes no sense.
Re: SSTC=Super Simple Tesla Coil?
Dr. Dark Current, Sun Mar 26 2006, 08:30PM
I think the capacitor in series with the primary would resonate with the primary, causing high frequency oscillations.
Even if not, and it will transform just by turns ratio, you can get for example: 10 turn primary, supplied with 300V peaks, and 2000 turn secondary (fine wire), thats 300/10*2000=60kV. Make 3000 turn secondary and you have 90kV...
Dr. Dark Current, Sun Mar 26 2006, 08:30PM
I think the capacitor in series with the primary would resonate with the primary, causing high frequency oscillations.
Even if not, and it will transform just by turns ratio, you can get for example: 10 turn primary, supplied with 300V peaks, and 2000 turn secondary (fine wire), thats 300/10*2000=60kV. Make 3000 turn secondary and you have 90kV...
Re: SSTC=Super Simple Tesla Coil?
Marko, Sun Mar 26 2006, 08:43PM
You have air - cored transformer with low coupling, dimmer would undergo a nice explosion for being shorted trough few turns of wire that represent diminutive impedance at 50Hz.
Adding capacitor in series wouldnt really make some kind of oscillation since SCR blocks it when it closes, so tought of using dimmer such way is just silly.
Marko, Sun Mar 26 2006, 08:43PM
You have air - cored transformer with low coupling, dimmer would undergo a nice explosion for being shorted trough few turns of wire that represent diminutive impedance at 50Hz.
Adding capacitor in series wouldnt really make some kind of oscillation since SCR blocks it when it closes, so tought of using dimmer such way is just silly.
Re: SSTC=Super Simple Tesla Coil?
dan, Sun Mar 26 2006, 08:55PM
Triac's are used in light dimmers and are basically bipolar SCR's. They could be used in an OLTC if they weren't so slow and you could get one big enough. But yeah the simplest Solid state tesla coil is an OLTC using big IGBT's for switching.
dan, Sun Mar 26 2006, 08:55PM
Triac's are used in light dimmers and are basically bipolar SCR's. They could be used in an OLTC if they weren't so slow and you could get one big enough. But yeah the simplest Solid state tesla coil is an OLTC using big IGBT's for switching.
Re: SSTC=Super Simple Tesla Coil?
EEYORE, Sun Mar 26 2006, 09:15PM
Some flourescent light electronic ballasts have been used to directly drive flybacks...Cant get simpler than that...Ive seen suitable ones on ebay that will run over 100watts. What do you mean by saying anything that produces more voltage output than a flyback?Some flybacks produce voltages higher than tesla coils.
Matt
EEYORE, Sun Mar 26 2006, 09:15PM
Some flourescent light electronic ballasts have been used to directly drive flybacks...Cant get simpler than that...Ive seen suitable ones on ebay that will run over 100watts. What do you mean by saying anything that produces more voltage output than a flyback?Some flybacks produce voltages higher than tesla coils.
Matt
Re: SSTC=Super Simple Tesla Coil?
vasil, Sun Mar 26 2006, 09:35PM
It is hard to believe that it would work, with the schema you have in mind...
Maibe...you can close the primary LC circuit through a dimmer, as here:
http://www.geocities.com/gemaria_ro/s33.html
but I think that the triac will be fryed at high frequency.
vasil, Sun Mar 26 2006, 09:35PM
It is hard to believe that it would work, with the schema you have in mind...
Maibe...you can close the primary LC circuit through a dimmer, as here:
http://www.geocities.com/gemaria_ro/s33.html
but I think that the triac will be fryed at high frequency.
Re: SSTC=Super Simple Tesla Coil?
Coyote Wilde, Sun Mar 26 2006, 09:37PM
Instead of a TC, use your light dimmer to drive an HE ignition coil.
Put the IC in a blast-proof box, if you want to run without a current-limiting capacitor and get arcs that can be drawn out to 2'. Expect the dimmer switch to not last long... nor the iggy.
A motor run or microwave oven capacitor is adaquate for current limiting, but your output is going to drop severely.
Coyote Wilde, Sun Mar 26 2006, 09:37PM
Instead of a TC, use your light dimmer to drive an HE ignition coil.
Put the IC in a blast-proof box, if you want to run without a current-limiting capacitor and get arcs that can be drawn out to 2'. Expect the dimmer switch to not last long... nor the iggy.
A motor run or microwave oven capacitor is adaquate for current limiting, but your output is going to drop severely.
Re: SSTC=Super Simple Tesla Coil?
Marko, Sun Mar 26 2006, 10:07PM
That what vasil showed is particulary an OLTC, but dimmer would never actually do right there.
It would not even chop the cap when it charges fully and it would blow at any higher powers simply because of overcurrent.
Putting IGBT in its place could from other side make a nice OLTC
Marko, Sun Mar 26 2006, 10:07PM
That what vasil showed is particulary an OLTC, but dimmer would never actually do right there.
It would not even chop the cap when it charges fully and it would blow at any higher powers simply because of overcurrent.
Putting IGBT in its place could from other side make a nice OLTC
Re: SSTC=Super Simple Tesla Coil?
Dr. Dark Current, Mon Mar 27 2006, 01:42PM
Maybe I'm just not lucky in finding good monitors...
EDIT: Err... can be an OLTC made with a heavy duty relay
or SCR as mentioned above? (just another silly idea on a simple TC really.)
Dr. Dark Current, Mon Mar 27 2006, 01:42PM
mattrg2 wrote ...
Some flourescent light electronic ballasts have been used to directly drive flybacks...Cant get simpler than that...Ive seen suitable ones on ebay that will run over 100watts. What do you mean by saying anything that produces more voltage output than a flyback?Some flybacks produce voltages higher than tesla coils.
Matt
Yeah, I knew someone will ask this. I've dismantled many old monitors just to take the flyback. But here's the problem: Most large flybacks, that are capable of outputting 80+ kV have built in HV capacitor, so they make a BANG! every second or so, it's too loud and the cap shorts out. The small flybacks that die at <50kV does not usually have that disadvantage, but doesnt output "fun" voltages.Some flourescent light electronic ballasts have been used to directly drive flybacks...Cant get simpler than that...Ive seen suitable ones on ebay that will run over 100watts. What do you mean by saying anything that produces more voltage output than a flyback?Some flybacks produce voltages higher than tesla coils.
Matt
Maybe I'm just not lucky in finding good monitors...
EDIT: Err... can be an OLTC made with a heavy duty relay
or SCR as mentioned above? (just another silly idea on a simple TC really.)Re: SSTC=Super Simple Tesla Coil?
Marko, Tue Mar 28 2006, 08:28PM
First tesla's resonant transformers ever were small multilayer coils, powered from few hundred volt supply and used kicker relay instead of spark gap.
In school I have similar small coil, uses only 24V supply and is supposed to generate maybe just couple of cm long spark.
It has diminutive topload, tunable helical primary, capacitor and relay as switch.
I never saw it in operation nor I remember details, so I cant tell more.
On any higher powers relay contacts would probably melt and weld shut, and it is also more inefficient than spark gap, and you aagain run in ''less than one turn priamry'' and other problems.
For SCR I concluded that it is big problem to turn it off.
FOr OLTC one could try to rectify mains halfwave, and make firing synchronous with halfcycle when 0V is present so SCR turns off when tank capacitor is rung to primary (now SCR would tend to turn off in ringing, and I dont know what side-effects would be) so idea prbably needs lots more of work.
Another could be using of GTO SCRs but they seem to be just too slow, altough I never saw that anybody tried OLTC with anything that is not IGBT.
Marko, Tue Mar 28 2006, 08:28PM
EDIT: Err... can be an OLTC made with a heavy duty relay or SCR as mentioned above? (just another silly idea on a simple TC really.)
First tesla's resonant transformers ever were small multilayer coils, powered from few hundred volt supply and used kicker relay instead of spark gap.
In school I have similar small coil, uses only 24V supply and is supposed to generate maybe just couple of cm long spark.
It has diminutive topload, tunable helical primary, capacitor and relay as switch.
I never saw it in operation nor I remember details, so I cant tell more.
On any higher powers relay contacts would probably melt and weld shut, and it is also more inefficient than spark gap, and you aagain run in ''less than one turn priamry'' and other problems.
For SCR I concluded that it is big problem to turn it off.
FOr OLTC one could try to rectify mains halfwave, and make firing synchronous with halfcycle when 0V is present so SCR turns off when tank capacitor is rung to primary (now SCR would tend to turn off in ringing, and I dont know what side-effects would be) so idea prbably needs lots more of work.
Another could be using of GTO SCRs but they seem to be just too slow, altough I never saw that anybody tried OLTC with anything that is not IGBT.
Re: SSTC=Super Simple Tesla Coil?
dan, Tue Mar 28 2006, 10:06PM
The SCR wouldn't work for the tank circuit in a OLTC since it is basically a rectifier that you can turn on. It will cut off the other part of the cycle. (The back-emf would probably kill the SCR too). A triac would be able to conduct both ways because it is basically two SCR's in anti-parallel. However to my knowledge the switch-on/off time in both directions is too slow and you may get some overlap or something. Then again a triac may work in a OLTC if you had one big enough but if it could be use in a OLTC I'm sure someone would have done it by now. But then again a suitable IGBT and drive circuitry would be much better and just as simple. But the simplest TC by a long shot is a good old spark gap tesla coil. I mean it doesn't get simpler than a HV source, Spark gap, tank cap, primary and secondary coil. (and top load which technically optional)
dan, Tue Mar 28 2006, 10:06PM
The SCR wouldn't work for the tank circuit in a OLTC since it is basically a rectifier that you can turn on. It will cut off the other part of the cycle. (The back-emf would probably kill the SCR too). A triac would be able to conduct both ways because it is basically two SCR's in anti-parallel. However to my knowledge the switch-on/off time in both directions is too slow and you may get some overlap or something. Then again a triac may work in a OLTC if you had one big enough but if it could be use in a OLTC I'm sure someone would have done it by now. But then again a suitable IGBT and drive circuitry would be much better and just as simple. But the simplest TC by a long shot is a good old spark gap tesla coil. I mean it doesn't get simpler than a HV source, Spark gap, tank cap, primary and secondary coil. (and top load which technically optional)
Re: SSTC=Super Simple Tesla Coil?
Marko, Wed Mar 29 2006, 11:56AM
Its not different neither with IGBTs, and problem is simply solved by using diode in reverse.
Slowness of SCRs is main problem together with needed circuit design for right turnoff.
Marko, Wed Mar 29 2006, 11:56AM
The SCR wouldn't work for the tank circuit in a OLTC since it is basically a rectifier that you can turn on. It will cut off the other part of the cycle.
Its not different neither with IGBTs, and problem is simply solved by using diode in reverse.
Slowness of SCRs is main problem together with needed circuit design for right turnoff.
Re: SSTC=Super Simple Tesla Coil?
dan, Wed Mar 29 2006, 01:16PM
Yes the reverse diode across the SCR would work however it increases the part count. Also finding a triac that can handle more than a 100A is probably harder than an IGBT of equal size and simply not worth it because it's too slow anyway. But this thread is about using a light dimmer to drive a TC which as stated before wouldn't work well.
dan, Wed Mar 29 2006, 01:16PM
Yes the reverse diode across the SCR would work however it increases the part count. Also finding a triac that can handle more than a 100A is probably harder than an IGBT of equal size and simply not worth it because it's too slow anyway. But this thread is about using a light dimmer to drive a TC which as stated before wouldn't work well.
Re: SSTC=Super Simple Tesla Coil?
Dr. Dark Current, Thu Mar 30 2006, 05:39PM
Hi all,
today I've made a simple triac circuit driving a 8 turn TC primary in series with a 0.1uF cap. It was limited with a 25W light bulb that even didn't light up so it was drawing a very little current. I managed to make some 5mm sparks with a mini TC secondary (800T, 4 by 15cm).
I'll try to improve it soon for bigger sparks (less primary turns, bigger cap, bigger triac). I'm aiming for at least 20mm sparks, generated by "brute force"
J.M.
Dr. Dark Current, Thu Mar 30 2006, 05:39PM
Hi all,
today I've made a simple triac circuit driving a 8 turn TC primary in series with a 0.1uF cap. It was limited with a 25W light bulb that even didn't light up so it was drawing a very little current. I managed to make some 5mm sparks with a mini TC secondary (800T, 4 by 15cm).
I'll try to improve it soon for bigger sparks (less primary turns, bigger cap, bigger triac). I'm aiming for at least 20mm sparks, generated by "brute force"
J.M.
Re: SSTC=Super Simple Tesla Coil?
Marko, Thu Mar 30 2006, 05:47PM
you should use 1 turn and maximize capacitor as possible, if you can make it resonate and dont roast the triac maybe you can get few more mm.
I also gotspark around that size and decided it isn't worth trying any more.
Marko, Thu Mar 30 2006, 05:47PM
you should use 1 turn and maximize capacitor as possible, if you can make it resonate and dont roast the triac maybe you can get few more mm.
I also gotspark around that size and decided it isn't worth trying any more.
Re: SSTC=Super Simple Tesla Coil?
GimpyJoe, Thu Mar 30 2006, 07:51PM
I'm pretty sure you're just running the coil like a regular transformer with a bit of inductive kick from the chopped waveform out of the dimmer.
GimpyJoe, Thu Mar 30 2006, 07:51PM
I'm pretty sure you're just running the coil like a regular transformer with a bit of inductive kick from the chopped waveform out of the dimmer.
Re: SSTC=Super Simple Tesla Coil?
Teodor Zafiroski, Tue Apr 07 2015, 02:57PM
Teodor Zafiroski, Tue Apr 07 2015, 02:57PM
Dr. Dark Current wrote ...
EDIT: Err... can be an OLTC made with a heavy duty relay or SCR as mentioned above? (just another silly idea on a simple TC really.)
I know that I'm about 8-9 years late, but about a year ago, this post inspired me to make this:EDIT: Err... can be an OLTC made with a heavy duty relay
or SCR as mentioned above? (just another silly idea on a simple TC really.)Re: SSTC=Super Simple Tesla Coil?
TeslaHighvoltMan, Wed Apr 08 2015, 05:58AM
? I don't think, that YOU made this! Please don't talk bullshit. The teslacoil shown in your link is a small commercial Teslacoil, produced in the former German Democratic Republic and was used at nearly every school for physics demo. You can buy this coils often on Ebay, here for example:
They can be run with 25V AC or DC, what makes them not very dangerous and they use the same simple principle like violet wand machines. So please don't say that YOU built this device
TeslaHighvoltMan, Wed Apr 08 2015, 05:58AM
Teodor Zafiroski wrote ...
Dr. Dark Current wrote ...
EDIT: Err... can be an OLTC made with a heavy duty relay or SCR as mentioned above? (just another silly idea on a simple TC really.)
I know that I'm about 8-9 years late, but about a year ago, this post inspired me to make this:EDIT: Err... can be an OLTC made with a heavy duty relay
or SCR as mentioned above? (just another silly idea on a simple TC really.)? I don't think, that YOU made this! Please don't talk bullshit. The teslacoil shown in your link is a small commercial Teslacoil, produced in the former German Democratic Republic and was used at nearly every school for physics demo. You can buy this coils often on Ebay, here for example:
They can be run with 25V AC or DC, what makes them not very dangerous and they use the same simple principle like violet wand machines. So please don't say that YOU built this device
Re: SSTC=Super Simple Tesla Coil?
dex, Wed Apr 08 2015, 08:17AM
How much arcing between contacts of the relay when it opens?
dex, Wed Apr 08 2015, 08:17AM
Teodor Zafiroski wrote ...
Dr. Dark Current wrote ...
EDIT: Err... can be an OLTC made with a heavy duty relay or SCR as mentioned above? (just another silly idea on a simple TC really.)
I know that I'm about 8-9 years late, but about a year ago, this post inspired me to make this:EDIT: Err... can be an OLTC made with a heavy duty relay
or SCR as mentioned above? (just another silly idea on a simple TC really.)How much arcing between contacts of the relay when it opens?
Re: SSTC=Super Simple Tesla Coil?
Teodor Zafiroski, Wed Apr 08 2015, 12:41PM
They were all in a pretty bad shape, dissasembled and in a pile of junk metal things and broken power electronics, they were to throw all the things in the junk, I scavenged quite a large quantity of heatsinks, transformers and also some of the parts of this Tesla col, which fitted in the screw holes quite nicely, but I thought it was a coincidence, because some of the holes in the relay didn't have corresponding holes in the stand.
I had a rough Idea at what should I do (a relay self oscillating behaving as a regular spark gap, inspired by the above-mentioned post), assembled it and it worked on 15Vrms, but the spark was very small. Then I got the idea to run it on mains voltage (230V), but after realizing that the impedance of the circuit is very small, I had to place a in decade scent lamp in series to limit the current.
The result was poor, and was not a huge improvement. Then, because the light from the light bulb bothered me a lot (I was using a 150W light bulb at that time), I wanted to replace it with another current limiting device, and the first to come at my mind was a magnetic lamp ballast. I tried it with the coil and with a little bit of tuning, reducing the turns count to only 2, I was able to get superb results regarding the 25W input. I have also tried it with a 40W ballast and not much improvement was noticed.
At that time, because of the lossy, non-varnished coil, I got some sparkovers and tracking problems because some turns were overlapping, so I decided to rewind the coil. There was a major improvement to the streamer length, I was satisfied with the result this coil gave at such low powers, and because the relay contacts got red hot in minutes when increasing the power input, I decided to scavenge the whole thing and go on to higher power coils. That's the story of this coil...
Teodor Zafiroski, Wed Apr 08 2015, 12:41PM
TeslaHighvoltMan wrote ...
? I don't think, that YOU made this! Please don't talk bullshit. The teslacoil shown in your link is a small commercial Teslacoil, produced in the former German Democratic Republic and was used at nearly every school for physics demo. You can buy this coils often on Ebay, here for example:
They can be run with 25V AC or DC, what makes them not very dangerous and they use the same simple principle like violet wand machines. So please don't say that YOU built this device
Some parts were scavenged, my teacher gave me access to my school's basement and let me to scavenge for parts, I found the secondary, the primary, the stand and the relay there, I was told that the relay was used in the old vibrator psu's, but it resembles the one in the link, and has very durable contacts... But I think the relay also came from the pre-assembled coil. Teodor Zafiroski wrote ...
Dr. Dark Current wrote ...
EDIT: Err... can be an OLTC made with a heavy duty relay or SCR as mentioned above? (just another silly idea on a simple TC really.)
I know that I'm about 8-9 years late, but about a year ago, this post inspired me to make this:EDIT: Err... can be an OLTC made with a heavy duty relay
or SCR as mentioned above? (just another silly idea on a simple TC really.)? I don't think, that YOU made this! Please don't talk bullshit. The teslacoil shown in your link is a small commercial Teslacoil, produced in the former German Democratic Republic and was used at nearly every school for physics demo. You can buy this coils often on Ebay, here for example:
They can be run with 25V AC or DC, what makes them not very dangerous and they use the same simple principle like violet wand machines. So please don't say that YOU built this device
They were all in a pretty bad shape, dissasembled and in a pile of junk metal things and broken power electronics, they were to throw all the things in the junk, I scavenged quite a large quantity of heatsinks, transformers and also some of the parts of this Tesla col, which fitted in the screw holes quite nicely, but I thought it was a coincidence, because some of the holes in the relay didn't have corresponding holes in the stand.
I had a rough Idea at what should I do (a relay self oscillating behaving as a regular spark gap, inspired by the above-mentioned post), assembled it and it worked on 15Vrms, but the spark was very small. Then I got the idea to run it on mains voltage (230V), but after realizing that the impedance of the circuit is very small, I had to place a in decade scent lamp in series to limit the current.
The result was poor, and was not a huge improvement. Then, because the light from the light bulb bothered me a lot (I was using a 150W light bulb at that time), I wanted to replace it with another current limiting device, and the first to come at my mind was a magnetic lamp ballast. I tried it with the coil and with a little bit of tuning, reducing the turns count to only 2, I was able to get superb results regarding the 25W input. I have also tried it with a 40W ballast and not much improvement was noticed.
At that time, because of the lossy, non-varnished coil, I got some sparkovers and tracking problems because some turns were overlapping, so I decided to rewind the coil. There was a major improvement to the streamer length, I was satisfied with the result this coil gave at such low powers, and because the relay contacts got red hot in minutes when increasing the power input, I decided to scavenge the whole thing and go on to higher power coils. That's the story of this coil...
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