Leonardo, if possible, I, too, would like to have the circuit diagram. I have done some experimenting on melting aluminum and brass with a copper coil driven by a 1800 W usual household induction heating plate circuit. Problem one is to bypass the security precautions, problem two is that the inductivity of my coil is much lower than the normal heating coils, so in order to keep the frequency of about 50 kHz I have to use much larger capacitors. This seems to change the complex resistance of the resonance circuit in a way to reduce effectivity. I want to get off the induction plate electronics.
Thank you Peter Am 11.02.2013 02:40, schrieb Leonardo Marsaglia: > Hello Gene, and thanks for your answer. > > I have the circuit in PDF format, would you like me to send it to you so > you can see it? > > 2013/2/10 Gene Heskett <ghesk...@wdtv.com> > >> On Sunday 10 February 2013 19:01:08 Leonardo Marsaglia did opine: >> Message additions Copyright Sunday 10 February 2013 by Gene Heskett >> >>> Hello Andy. >>> >>> http://imagebin.org/246204 >>> >>> Here's a picture of what I scoped the other day, this is the signal >>> coming out from the IC's that we use to fire the igbt's, as you can see >>> those spikes are a little dangerous I think. >> First, I am a CET, and a retired (mostly) broadcast engineer. >> >> 2nd, Correct, both the spikes, and all that racket on the falling edge >> bothers me, a lot. >> >> First on the overvolt spikes, I'd make sure the scope ground is floating so >> that you can attach it to the circuits common. They may not be near as >> pronounced if a ground loop is eliminated. >> >> 2nd, that double or triple shuffle on the falling edge isn't at all good. >> Its needless switching and heating in the transistors./ >> >> Perhaps the grounding and supply bypassing are both suspect. I'd check to >> see what effect a .1 paper/mylar capacitor across the buses might indicate >> poor bypassing. >> >> Do you have a URL to that circuit? I'll take a look at it if I can. >> >>> I've talking a lot with Tim and he's a great help, he's always helping >>> me with his advices and knowledge. >>> >>> About using an arduino or fpga, I've been thinking about that too, I >>> need to catch on with VHDL since I've only made some simple counters >>> and multiplexers but I really like the idea of make a whole system from >>> an fpga. >>> >>> Anyway, the main problem here is after the firing IC's since the >>> oscilator is generating a perfect square wave form. >>> >>> >>> 2013/2/10 andy pugh <bodge...@gmail.com> >>> >>>> On 10 February 2013 22:15, Leonardo Marsaglia >>>> >>>> <leonardomarsagli...@gmail.com> wrote: >>>>> based on DIY circuits found on the internet. >>>> I guess you have seen: >>>> http://webpages.charter.net/dawill/tmoranwms/Elec_IndHeat1.html >>>> (Lots of clever stuff, much better done in software now) >>>> >>>>> Anyway, the real deal here is always how to have a clean square >>>>> signal to fire the igbt's. >>>> Sounds like a job for Arduino or FPGA. I can't help feeling that there >>>> ought to be a suitable Mesa module, but Arduino's have PWMs that share >>>> a clock, so for suitable thresholds are guaranteed not to overlap. I >>>> don't know how smoothly you can change frequency >>>> >>>> -- >>>> atp >>>> If you can't fix it, you don't own it. >>>> http://www.ifixit.com/Manifesto >>>> >>>> >>>> ---------------------------------------------------------------------- >>>> -------- Free Next-Gen Firewall Hardware Offer >>>> Buy your Sophos next-gen firewall before the end March 2013 >>>> and get the hardware for free! Learn more. >>>> http://p.sf.net/sfu/sophos-d2d-feb >>>> _______________________________________________ >>>> Emc-users mailing list >>>> Emc-users@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> Cheers, Gene >> -- >> "There are four boxes to be used in defense of liberty: >> soap, ballot, jury, and ammo. Please use in that order." >> -Ed Howdershelt (Author) >> My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! >> My views >> <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> >> It matters not whether you win or lose; what matters is whether I I win or >> lose. >> -- Darrin Weinberg >> I was taught to respect my elders, but its getting >> harder and harder to find any... >> >> >> ------------------------------------------------------------------------------ >> Free Next-Gen Firewall Hardware Offer >> Buy your Sophos next-gen firewall before the end March 2013 >> and get the hardware for free! Learn more. >> http://p.sf.net/sfu/sophos-d2d-feb >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > > ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
