Resonance Effects For Everyone To Share

[ren]

good stuff luc. I am waiting to get some more PWM's but hopefully soon I can configure something similar. How stable is the circuit? Have you had any problems with parts blowing? And may I ask how you have tuned your coils? Has it been a matter of winding a secondary, measuring it then winding a primary to match, or has it just been hit and miss?

Thanks again, and great work.

Ren

[cody]

to Ren about tuning coils

Ren, If you watch his 6th vidio you can see he used three turns on the secondary of his coil to hit resonance between the two coils. Instead of using a wire with conduit on it(for the 3 turn wire), it would be easier to use a bare wire there with say about ten turns. Have that said bare wire connected at the bottom and then you can tap onto the bare wire at whichever turn its in resonance at. Are you following? So instead of making a coil with 3 turns, one with 4 and so on, just make one that you can vary by taping onto that turn you desire. You should find resonance between the two somewhere around a 10 to 1 ratio, so if you have one coil with 1000 turns on it, you will find resonance somewhere around the tenth turn on the other coil. I cant remember if this is quarter or half wave resonance between the two. As far as measurments, sorry i cant help you there, but if you set up your coils around those parameters and play with the tuning, adjusting what frequency and what turn your taped on you should be able to find resonance. How will you know, its when the power starts coming though the coils allowing you to get those effects with the light bulbs and such. Hope this helps.

[ren]

Thanks Cody, I did watch the video. I was just wondering if he did some maths before, or if it is simply a matter of adjusting the primary. You can see some of the secondaries I have wound here. I want to make sure the primary is done right, as I might not get too many chances to buy the copper again ($$$). I was planning on using copper pipe, so adjusting the connection point will probably be the way to go.

[cody]

here is some formulas

List of Tesla Coil Formulas
this should help if you want to do some math on the resonant frequencys and primary capacitance and such. Some tips for your primary design after screwing this up several times. Copper pipe works great for the primary and a fuse holder works pretty good for a tap. You could save your money and just use a striped 12 or 14 ga wire for this experiment, it will preform the same. For these low voltage experements that are taking place in this thread i would not recommend wasting your time with the pancake coil, this is used for the fact that when you try pushing a high voltage between the two coils they will arc across each other destroying your coils, this wants to occur at the top of the primary, so if you make it far away(pancake) you dont get that arcing, however you also dont get as much power through. With these low primary voltage circuits in this thread you should use a primary running right up with the secondary, the closer you get the more power you will get out, and you shouldnt have any worry about arcing between them with these low voltages. Put more turns on the primary than you intend to use, most of my designs hit resonance taped on the 15th turn. From my experence in building several of these guys, your secondary capacitance in the pictures is going to be to big. You only need a large capacitance if you are getting a lot of power through and with this setup you wont be pushing much through, dont be surprised if you end up with something tiny covered in aluminum foil on top preforming much better than those balls you have. This design is no good for a standard tesla coil, it will arc and be no good, but is the right direction to go for these low power guys. Sorry for rambeling, Ive spent a lot of time messing around with this setup and i could keep going, ill shut up now. Have fun.

[ren]

No Cody, I appreciate your input. I should of stated that my experiment is to see if I can step up power twice here. The first step will be from 12v with a PWM pulsing a ignition coil. The HV off the ignition coil will be rectified and that is what the primary coil will see. Preliminary tests show that the ignition coil will fill up a hv cap and consistently spark/arc so I was going to simply add a primary in that part of the circuit, with a simple spark gap or rotorary spark gap if need be. I know its crude, but Ive seen it done before.

I have no access (or real knowledge) to/with HV so I decided to start off a smaller source. The Sphere may or may not be used in the end....


Sorry to hijack your thread Luc, I guess its all related though.

Thanks for the tips Cody, I might try the primary coil wound close to the secondary, rather than flat pancake it.

[Joit]

Hehe Cody, Dont shut up, better, go on and find a nice Solution.

But i think more, that gotoluc trys to get out a better Output over the Resonance, hes not trying do build HV like the Teslacoil does.

[gotoluc]

Hi Cody and ren,

thanks for your interest and sharing.

Here is some information on the coil. I did not use or ever use any math to make a coil. I do not even use an LC resonance calculators. I've got drawer of capacitors I salvage from CRT monitors and other stuff I pickup for free from the garbage! when I want to find the resonance of a coil I try different cap values and sweep the signal generator until I see the neon bulb light (using one wire of neon to one side of coil)

The wire I used to make the coil was a salvage of a primary of an ignition coil that was taken apart for a test. It looks to be 19AWG or 1mm. I had an emty spool which is 3" or 76mm diameter by 3 1/2" or 89mm high of winding space between each ends. I winded as much of the 19AWG or 1mm wire I could on it but only a single layer which looks to be about 120 turns. The DC resistance of the coil is 1 ohm and resonate at 352Khz as air core and using a 335pf capacitor in series and a square wave as input.

It took time to get to this but not too long to write it

Hope this helps answer your questions.

Luc

[najman100]

Hi Jetijs,

thanks for your positive comment and the information on your HV at HF tests.

Here is where I got the IR2103: IR2103 - eBay (item 220208395817 end time Dec-27-08 23:12:37 PST)

Luc

Thanks LUC for the good info as alwaise i just bought 10 ir 2103 from that link .
and now i am debating if i buy the 100ms/a or 150ms/a oscilloscope ,what do you have .and that signal generator where did you buy it ?
Thank again you work really inspired me .

Najman

[Jetijs]

Hi Najman
I also just bought some of the 2103
As for function generators, I found this one the cheapest on ebay:
New VC2002 Function Signal Generator (0.2Hz - 2MHz) - eBay (item 110322817125 end time Dec-13-08 16:22:13 PST)
So far I haven't got any problems with it. It supports frequencies up to 2MHz and output sine, square and sawtooth waves
Hope this helps.

[boguslaw]

gotoluc

I'm trying to compute your circuit series resonant frequency for "transverse waves" and it seems to be quite low ~ 0.336 Hz.Probably I'm wrong.

Could someone check it ?

Please compute your turns.

[boguslaw]

WOW!

Seems that your 352Khz for that coil is very close to 7th harmonic of longitudinal resonant frequency.Please compute wire length exactly !

[Armagdn03]

wire length will not have an effect, what is being shown what is known as lumped transmission line theory, where the electrical length (as opposed to the physical) is condensed due to geometry. The electrical length is the equivalent physical length of the free space permittivity and permeability of the vacuum condensed by a factor for the particular coil. Energy propagation is retarded in such structures, and you will find the resonant frequencies will be dependant more on the capacitance and inductance properties of the coil, than the wire length.

[gotoluc]

Thanks LUC for the good info as alwaise i just bought 10 ir 2103 from that link .
and now i am debating if i buy the 100ms/a or 150ms/a oscilloscope ,what do you have .and that signal generator where did you buy it ?
Thank again you work really inspired me .

Najman

Hi Najman,

I think the DSO-2090 USB Scope which is 100ms 40Mhz should be good enough for this kind of work. But one thing I found out after I bought it is the 100ms/ sample per second resolution is when one probe is used, so when you have 2 probes it drops to 50ms/ sample per second on each. Nothing beats the resolution of the old analogue scope but they are heavy and bulky and expensive if you want one that displays all the data. The USB you can get for as low as $200. and it includes a spectrum analyzer. All this in a 4" x 7 1/2" x 1 1/4" box that has next to no weight.

As for the signal generator. You could just use a 555 since only square wave is needed. Here is a link to an online test circuit giving the capacitor and resistor values needed for the frequency range you need: Astable 555 Multivibrator - doc00019

However for convenience nothing beats a built signal generator ready to go at what ever frequency you want. 2Mhz is all you may need for this but If I had the money to replace mine I would buy a 21Mhz or higher and one that I could adjust pulse width (duty cycle). You should fine plenty of used ones on ebay.

Hope this helps.

Luc

[najman100]

Hi Najman
I also just bought some of the 2103
As for function generators, I found this one the cheapest on ebay:
New VC2002 Function Signal Generator (0.2Hz - 2MHz) - eBay (item 110322817125 end time Dec-13-08 16:22:13 PST)
So far I haven't got any problems with it. It supports frequencies up to 2MHz and output sine, square and sawtooth waves
Hope this helps.

Hi Najman,

I think the DSO-2090 USB Scope which is 100ms 40Mhz should be good enough for this kind of work. But one thing I found out after I bought it is the 100ms/ sample per second resolution is when one probe is used, so when you have 2 probes it drops to 50ms/ sample per second on each. Nothing beats the resolution of the old analogue scope but they are heavy and bulky and expensive if you want one that displays all the data. The USB you can get for as low as $200. and it includes a spectrum analyzer. All this in a 4" x 7 1/2" x 1 1/4" box that has next to no weight.

As for the signal generator. You could just use a 555 since only square wave is needed. Here is a link to an online test circuit giving the capacitor and resistor values needed for the frequency range you need: Astable 555 Multivibrator - doc00019

However for convenience nothing beats a built signal generator ready to go at what ever frequency you want. 2Mhz is all you may need for this but If I had the money to replace mine I would buy a 21Mhz or higher and one that I could adjust pulse width (duty cycle). You should fine plenty of used ones on ebay.

Hope this helps.

Luc

Thanks Jetijs for the link i already found that from the ebay seller nice to hear that is working fine .
Thank gotoluc also for the link i quess i will buy the 150 ms ther is not much big difference in price .

Najman

[cody]

Im sorry ren, i didnt know you were trying to make a TC. Transistors in PWMs like to blow doing what you are doing, i didnt have much success with that until i paralleled two in my pwm. I also dont think i was understanding what gotoluc was trying to do here. You are wanting to step the radiant down into a directly usable form of energy, not step it up into some wild voltage. Thats a great idea, have you done any efficiency tests yet?