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*To*: tesla@xxxxxxxxxx*Subject*: Re: Resonant cap?*From*: "Tesla list" <tesla@xxxxxxxxxx>*Date*: Mon, 29 Jan 2007 21:10:28 -0700*Delivered-to*: testla@xxxxxxxxxx*Delivered-to*: tesla@xxxxxxxxxx*Old-return-path*: <tcmlmod@xxxxxxxxxxxxx>*Resent-date*: Mon, 29 Jan 2007 21:10:27 -0700 (MST)*Resent-from*: tesla@xxxxxxxxxx*Resent-message-id*: <mFl7ufgbgmF.A.bNB.zUsvFB@chip1>*Resent-sender*: tesla-request@xxxxxxxxxx

Original poster: "Steve Ward" <steve.ward@xxxxxxxxx> Hi JT, Some assumptions must be made, firstly that the transformer acts as a constant current source. Current = charge per time (i=Q/t). Also, charge = capacitance times voltage (Q=CV). With these 2 equations you can solve for how long it will take to charge a given capacitor to whatever your desired voltage is (usually a little less than VRMS*sqrt(2)). Given 3kvAC, thats roughly 4.2kV, so lets say you want to charge to 4kVDC. Lets say for example you want to charge whatever capacitor 120 times a second (so in 8.333mS). So we find the charge possible given the supply current and the time alloted. .01A*.00833s=.0000833C. Now we find the capacitance: .0000833C/4000V = 20.8nF. So that is the value i would aim for personally, but you should be able to extrapolate from the information ive given if you desire some other break-rate than 120bps. To keep the units clear: Current (i) in amps (A) Charge (Q) in coulombs (C) Time (t) seconds (s) Capacitance (C) in farads (F) Voltage (V) in volts (V) Steve Ward On 1/29/07, Tesla list <tesla@xxxxxxxxxx> wrote:

Original poster: "JT Bowles" <jasotb@xxxxxxxxxxx> I am just thinking of rectifying the output to DC now. It will make things much simpler. One problem arises though; how the heck does one determine the appropriate cap size, with a HV DC source? >From: "Tesla list" <tesla@xxxxxxxxxx> >To: tesla@xxxxxxxxxx >Subject: Re: Resonant cap? >Date: Sun, 28 Jan 2007 14:32:26 -0700 > >Original poster: Mike <megavolts61@xxxxxxxxx> > >That's where the 26.5pF came from, Gerry. JT, does it show on >the ferrite any numbers? There are a few vendors of ferrite cores >that you can look up the properties of ferrite materials. Perhaps >it's possible to build a driver circuit that is a bit lower >frequency...say 5 - 10 kHz which would allow you a larger resonant >cap size. The only other suggestion is to rectify the output and >use a voltage multiplying circuit to raise the output >voltage. Then, you could fire your coil at whatever frequency you wish. >Mike > > > >Original poster: "JT Bowles" <jasotb@xxxxxxxxxxx> > >Hi JT, > >For your 30KHz transformer, the formulas that you want are these: > >Zout = Vs_oc_rms/Is_sc_rms > >Cres (nf) = 10^9 / (2*pi*freq*Zout) > >use 30KHz for your frequency. The assumption here is that the >winding resistance is insignificant compared to the current limiting >leakage reactance. If you can measure the primary and secondary >winding resistance, we can verify the assumption. > >Gerry R. > >>-----------------------------------------------------------------------------> > >For the...thrid time now, online calculators only work for >50/60Hz....... > >My Transformer runs at 30kHz, 2KV AC, 10ma. > >Again, you cannot use an online calculator in this case. Go back to >deep fried neon. Look above where you put in the voltage and current. >It has a selection for"50 Hz" and "60Hz". NO 30KHZ. > >So far, I have only received one real response; 26.5pF. I calculated >by hand and received a similar answer. I need some more opinions >though. > > >We won't tell. Get more on ><http://us.rd.yahoo.com/evt=49980/*http://tv.yahoo.com/collections/265>shows >you hate to love >(and love to hate):><http://us.rd.yahoo.com/evt=49980/*http://tv.yahoo.com/collections/265>Yahoo!>TV's Guilty Pleasures list. > _________________________________________________________________ Valentine's Day -- Shop for gifts that spell L-O-V-E at MSN Shopping http://shopping.msn.com/content/shp/?ctId=8323,ptnrid=37,ptnrdata=24095&tcode=wlmtagline

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