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Resonance and its harmonic

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Andy

Wed Jan 15 2014, 06:23PM

Registered Member #4266 Joined: Fri Dec 16 2011, 03:15AM
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I was hopeing for more volts or less loss, I can increase the source power but at 120volt its around 1mv. Wouldn't adding a resonance part for the transformer effect the filter as it will be in series with the filter, if I change one value to match it will throw the other values out.
Good point about the resistors :)

Mattski

Sat Jan 18 2014, 02:51AM

Registered Member #1792 Joined: Fri Oct 31 2008, 08:12PM
Location: University of California
Posts: 527

Andy, if you want to have a better understanding of how these circuits work you'll often be better served by understanding the theory rather than plugging stuff into a simulator, which can give weird and incorrect answers, especially if you're starting with weird circuits which don't seem to really do what you're looking to accomplish. If high voltage is what you're after there are plenty of well-established ways to generate high voltages, and you're not likely to come up with a substantially new method if you don't understand the basic circuit theory.

If you want to go back to the basics a bit these references (among others) may help:

has some free tutorials that seem okay.

is an old edition of a basic circuits textbook which you can pick up for under $10, I have this edition on my shelf and it's a perfectly good as basic circuit theory has not changed recently. From a basic linear circuit text like this you can learn how to calculate the response of your filter to a 60Hz sine wave.

In the case of your simulation you can see that there's a lot of high frequency content, it looks like a ~1mS period so it's a ~1kHz signal. What may be happening is that a 500kHz bandpass filter should pass very little of a 60Hz sinusoid so the signal you see could be mainly simulation error. Or it could be some transient effects that haven't settled out because the transient simulation didn't run long enough to reach steady state.

Andy

Sat Jan 18 2014, 06:13AM

Registered Member #4266 Joined: Fri Dec 16 2011, 03:15AM
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Cheers for the link to that website, I'm starting to get a better idea how it works, below the resistors and capacitors makes a bandpass with high/low, the inductors then make the caps go to resonance. One is at the center frequency and the voltage is high, times ten the frequency and the voltage drops majorly.

It doesn't work as expected, I thought it would chop up the 50hz wave into 500khz cycles following the amplitude of the 50hz. Is there a passive system that can do that?

I was reading Practical electronics for inventors by Paul Scherz, might have to reread it again now.

Proud Mary

Sat Jan 18 2014, 07:08AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
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Andy, when you decide to make the break away from playing with circuit simulators to design something intended to actually work in the real world, you'll find that the bizarre component values produced by the simulator are not actually manufactured by anyone, so you have to select components from the preferred values system, industry standards (in fact international standard IEC 60063) defining the values of capacitors, resistors, inductors and Zener diodes - a system you should waste no time in getting to grips with:

My advice: learn the basics of electricity and magnetism, Ohm's Law and the basic properties of resistors, capacitors, and inductors, so you can design at least simple DC circuits without any sort of calculator except what you can work out with basic maths on a sheet of paper. Once you have grasped these fundamentals you'll be in a proper position to move onto the more advanced and creative ideas in which you show so much interest.

Scientific experiments should be written up under the headings (1) Object (2) Method (3) Results.

No one can make head or tail of your questions because you never properly specify the Object of the investigation, without which all that follows can only be nonsense. So you must define as clearly as ever you can what it is exactly that you are trying to do. Then if you get into trouble with your experiment others will be able to follow your reasoning and hopefully see where you have gone wrong.

Mattski

Mon Jan 20 2014, 12:09AM

Registered Member #1792 Joined: Fri Oct 31 2008, 08:12PM
Location: University of California
Posts: 527

Andy wrote ...

It doesn't work as expected, I thought it would chop up the 50hz wave into 500khz cycles following the amplitude of the 50hz. Is there a passive system that can do that?

No circuit composed of linear components can do this (covered fairly early in most linear circuit texts). A 500kHz BPF will pass a 500kHz signal but it won't create it out of thin air.

Andy

Mon Jan 20 2014, 12:15AM

Registered Member #4266 Joined: Fri Dec 16 2011, 03:15AM
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I think what I'm after is a oscillator circuit.
Thinking about a project, remembered standard wave, what wiki says is mismatched impedance, I was wondering how to create that with this circuit

Were the inductor on the left is, I think the maths will be quiet heavy and was wondering if you have a basic example.

Cheers

Mattski

Mon Jan 20 2014, 05:57AM

Registered Member #1792 Joined: Fri Oct 31 2008, 08:12PM
Location: University of California
Posts: 527

What you have pictured is not an oscillator unless you're trying to do some esoteric kind of relaxation oscillator using a spark gaps as the switching element in which case you need to specify how the spark gap is constructed instead of providing three terminals with no further desciption...

But I digress because the important thing is that I (and probably most/all here) are quite befuddled as to what you're trying to do. And to be honest you're going to have a hard time of it without buckling down and learning some circuit analysis techniques and some theory. Really sit down explain what you want to achieve in terms of "these terminals takes this kind of input (voltage, current, impedance) and in that condition these terminals should then have this output (voltage, current, impedance, etc)". Sit down and analyze how your circuit really works and try to explain that to us. What is the basic flow of operation of your circuit? What elements are there for what purpose? Why put a 10uF cap in series with a .0001pF cap? Incidentally a .0001pF cap is probably not physically realizable, parasitic wire to wire capacitances will be larger. Similarly, 1kH is unrealistic. This is one of the dangers of simulators is coming up with unrealizable circuits. Do you have a good model for all of these esoteric things like "two Al rods 5m ..."?

Mary's post is a good one. With these posts you're jumping straight into the middle of a complicated project (which may or may not be workable) without explaining how you got there.

Andy

Mon Jan 20 2014, 06:26AM

Registered Member #4266 Joined: Fri Dec 16 2011, 03:15AM
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Posts: 874

Yep,
About the capacitor, I thought that adding caps in series, was like the same as moving the plates thorougher away from each other, the object of a lot in series, was to make the same capacitance from the top of the stack to the bottom as from the top of the stack to 30km up, there by half the voltage from 30km to ground(approx 300kv from wiki article earlier), which should appear on the 10uF cap.. The larger 10uF cap was because it should take the full voltage of the ac from 30km up to below the stack(ground).
Got the relaxation oscillator design from that website you linked to, I think it was called that, the above explains the right side if I've communicated it correctly, the left side is fired after the right side sparkgap has fired and the potential gradient is close to zero, the left side fires and charges up the inductor, which then fires when the arc is extinguished back to the antenna at the top.
The close proximity of the second antennae pics up the now 502khz signal, and superimpose it back onto the main circuit, with enough voltage for anything in the electric filed to start radiating at 502khz with the capacitors(stack, and 30km to top of stack) become like short circuit.
The inductor should be doable at 100kH, if the formula for inductance holds to a rough guide.
The standard wave thing, I just mediating about the idea, and that popped up, thought the subby was saying to add it to the circuit just don't know why yet

I think I'm better off just building the whole thing and getting the info that way, you can only understand something if you arrived there with the information.

Cheers

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