salter

not at all; however feel free to continue this is interesting. lol Merged post follows: Consecutive posts merged THATS INCREDIBLE lol

i made the cap 4 nf and messed with the inductor until it matched. i used a 10k volt 30mA neon transformer aww i have to post code? but im a lazy teenager. lol ill just describe it its pretty simple. I used the thing i talked about above with three fields: constant and two "n's" as drop down menus, one in a numerator and one in a denomitator. By each n there is a "modify n" button that lets you get things like sin(ln(n)) or sin(n+1). then there is a next term button and it adds up to 8 terms that you enter in the same method. it then does operations based on what you entered using math.whatever commands. I made it a little faster by making it skip over all the if statements for terms past the first one using If constA = 0 Else... then listing the other ifs. It's slow but less code than actually having it interperet each character lol and then it runs through this '(tons of Dims) For Me.L = 1 To num '(A1 = const1 * TermN1, A2 = TermND2, etc. using ifs) sum = (A1 / A2) + (A3 / A4) + (A5 / A6) + (A7 / A8) + (A9 / A10) + (A11/A12) + (A13/A14) + (A15/A16)+ sum X = X + 1 TextBox2.Text = sum next end sub Merged post follows: Consecutive posts mergedit just runs it up to a specified number of terms and gives you the sum. it shouldn't be hard to find convergence using that... i could make it find convergence but it would be a pain. have it save the sums and find where it no longer changes past the third decimal place or something like that. Before i figured out how to make it input an equation i just put in the formula in the code where the if statements would be and did it that way. I tested one up to 500,000 then 1,000,000 and when they were the same i figured it was safe to say it converged to that. lol the one on my calculator displays the newest "sum" value over and over so that you can watch it work and tell where it stops changing then stop it, but i cant figure out how to make VB display it every time it loops. even though i wrote textbox2.text = sum within the loop it doesn't display it until afterwards.

I have done plenty of experiments with electrolysis myself... when i used salt water and copper electrodes i got orange and green in the water, which has the right color for copper chloride... idk what you are doing that is giving the different result (could be additives in salt), but i do know that if you use sodium hydroxide instead of sodium chloride you don't get anything but hydrogen and oxygen gas. I also tried to avoid getting salts or whatever they are using different electrodes and i found that anything i could get my hands on (i was going to do platinum but didnt feel like spending much money) created something. As for sulfuric acid, copper sulfate will make it in water. I found that one out the hard way in the bottom of a mine shaft... we were collecting long blue hairs of the stuff to sell and the dust settled on my skin and when i sweated it wasn't exactly fun. lol

Well i am 16. idk if you consider that a kid or not. and btw i don't even remember the things i posted about capacitors and tesla coils earlier. i figured out all the answers outside of forums and have my coil up and running.i wish my school offered programming and AP physics... then most of my questions would probably be something i already knew. i think what i'm going to do regarding the programming thing is teach myself multiple languages. they are all nice to know and i enjoy it so why not. lol i can get it to work in vb just not fast enough. sorry im not quoting and everything is slurred together. im doing this on my cell

Thanks for all the help. I was hoping that there was a simple command for the input of a formula but apparently not in VB... the only reason im using VB is cause it was the first thing i found to download. Perhaps C++ would be a better choice? I set up my own way of doing it using a drop down menu with different possibilities and then wrote code which ran operations based on the choice... you can also choose to alter the value of X again... aka you could choose ln(x) the first time then press modify x and choose sin(x) and you would get ln(sin(x)). works but i'm trying to add up terms of a sequence so its too slow and the simple program i wrote on my TI-84 is actually faster. Merged post follows: Consecutive posts mergedbtw this is for calculating what wierd series converge to in calc 2. So i need much more than polynomials etc.

I just started learning how to do VB and I've been searching everywhere for hours and can't find anything on how to do something. I want a user to be able to input an equation in terms of x that the program can then run values through. can anyone help?

In previous threads, i have mentioned that i am building a tesla coil with no physics/electronics knowledge beyond what I have taught myself. So if you see something in the paper about a kid blowing himself up it's probably me. lol. But anyway, I need to build an HV capacitor somewhere between 1 and 40 nF rated for close to 28k volts to account for surges and gains in the capacitor. so i did some research... eventually i chose plexiglass for my dielectric. I picked up some .093 inch plexiglass at Home Depot, and proceded to cut out 3 inch squares. i then made 2.5 inch circles of aluminum foil using the bottom of a can and alternated between aluminum and plexiglass, lining up the circles to the best to my ability, putting out tabs of aluminum to the right side for the first aluminum circle and then to the left for the second, etc. I hot glued around each plate to prevent contact between plates of the opposite charge. I used 20 plates. I then linked all the tabs on either side by folding them together. i attached the leads of my 10k volt 30mA 60Hz neon transformer to the tabs, then added a second set of wires going off that i could short to discharge the capacitor. I submerged the entire apparatus in mineral oil as an additional precation against arcing. Well, as I'm sure anyone with any knowledge of basic electronics (not myself) has figured out, it didn't work. I got small sparks off of the secondary wires when i touched them (while the apparatus was plugged in), but not even enough to make an arc. There was nothing after i unplugged it. The capacitor retained no charge. I figure that, of all the possible reasons, two of the most likely are that either: a. i accidentially made a short when building the capacitor (no visible arcs existed) or b. the aluminum foil isn't conductive enough and i should get copper sheets. i suppose the AC could have something to do with it... But the bottom line is i dont know why it didn't work. So any help would be appreciated. P.S. i understand that the capacitor doesn't match my goal of 1 to 40nf, but that was because i decided to test it before i finished. The one i built should have been about .9nF according to my calculations. Thanks

I was looking up formulas for inductance of a coil with an air core and i found this one. L=(r^2*n^2)/(9r+10l), where L is inductance, r is radius of coils, n is number of coils and l is length of coil... what is length of coil? is it total conductor in the coil? also, i need to calculate resonance of an LC circuit. i got the formula R=1/2pi(LC)^1/2... does current or voltage affect resonance? does resistance?

So i recently started doing research on how to make my own tesla coil. The design that i decided on is pretty simple- the main coil circuit consists of a power supply, a capacitor, an inductor with only a few winds, and a spark gap as a switch. the secondary is just a coil around pvc pipe with an aluminum bowl type of thing on the top (i havn't decided exactly what to do for that part). So figured out most of the details... a few things still evade me. I was going to use a 66 watt compact flourescent sawed off at the bulb linked to an old flyback transformer... Some sites i found say that the design i have works with a DC power supply like i described above and i don't see why it would not. However, other sites say it has to be AC for this particular design. I also wonder if the wattage will be too low to get any real results... i suppose if my capacitor is rated at a high enough number of farads it is unimportant what the power supply's wattage is... Sorry about the lack of knowledge here. completely self-taught. I've also seen things on a few sites about saftey spark gaps. the question i have is... if you have a saftey gap the distance has to be within the distance that the voltage times the square root of 2 accounts for... right? wouldn't this take away from the effectiveness of the device? Because if the saftey gap is within V*1.414 then the main gap has to be closer than it, which would not allow the capacitor to reach it's full potential. One more thing regarding the capacitors... is the rate that the joules within the capacitor grows per volt equal to the total capacity in joules divided by V*1.414 - V? i also need to determine the speed at which the primary coil and secondary coil oscillate... whatever that means, help please, so that i can get the right ratios down. I also need to calculate/measure frequency for the same reason. (how?) For all of these things i need the initial voltages and i might need amperage too... how can i figure these out? im afraid i would blow up my multimeter. Probably. lol Should i just go with a neon transformer because it's more straitforwards? initial voltage, etc. is already given. If it helps, the general idea i used is at http://members.tm.net/lapointe/HowItWorks.htm