The high resolution timer together with the comparators should be able to do exactly what you say if properly configured. I got square wave out yesterday and expect to spend a few hours before it's correctly configured for EDM.
These micro controllers have only been available for a few years at most, they are really good and available from maybe a few dollars each. Regards Nicklas Karlsson On Wed, 9 Mar 2016 14:10:03 +0800 TJoseph Powderly <[email protected]> wrote: > Niklas Pete, > if you want ISOPULS ( isoenergetic pulses that have uniform craters ) > then all the worry about frequency is useless > > if you dont need uniforn surface finish, then ignore this comment > > if you DO want uniform surface finish, then you do not use repetitive > pulse grnerator > instead, you wait for ionization ( a kind of indetermonate latency of > conduction) > THEN start decrementing the ontime. This was the joules delivered are > equal ( the energy is equal ) > Once the ontime is finished, the current is turned off and the off time > is waited > THEN you turn on a tiny exciting voltage and wait for another ionization > ( and voltage drop ) before starting the next ontime current flow. > > some pix: > http://www.edm-products.com/Dielectrics/ifase/ifase_1.htm > look at figure 3 > if you wait for the ionization (wait for the voltage to drop) > and then deliver current for the duraction of 'ontime', > the energy delivered will be uniform, and the surface crater will be uniform > if not, the energy per pulse in non-uniform, to the extreme that some > pulses deliver nearly no energy! > see figure 4, > when the strategy is isoenergetic, the current waveform will be uniform > and the leading edge of the voltage will vary. > if not isoenergetic, the leading edge is static on the scope, > but the current wave form will vary. > > On 03/09/2016 01:59 AM, Nicklas Karlsson wrote: > > A microcontroller with suitable peripherals for power conversion is cheap > > and do the work much better. I know about: stm32f334, Infineon xmc4xxx > > something, maybe texas instruments and Microchip. > > > > I am working with stm32f334. It have a high resolution timer equal to about > > 4GHz clock frequency with a lot of triggering options, DAC, fast > > comparators and cost maybe a few dollars. There are also cheap development > > boards available. > > > > I guess spindle off/on signal may be useful to turn off/on generator and > > some m-code is useful for the parameters? > > > > Regards Nicklas Karlsson > > > > > > > > On Tue, 8 Mar 2016 16:47:42 +0000 (UTC) > > Pete_Gruendeman <[email protected]> wrote: > > > >> Hi Nicklas: > >> I am writing with a request for what might be speculation on your > >> part. Given what others have said about pulse frequency, and what is > >> written in the Poco tech manuals (frequencies of approximately 8.33- > >> 50kHz, derived from varying on and off times), would it be reasonable to > >> produce the pulse timing from and at the same time that the PC is > >> directing motion control? Erosion pulse generation could be treated as > >> another axis-- maybe? I am concerned that the standard parport provides > >> rather coarse granularity (increments) between one size and another size > >> of pulse, especially as the pulse durations get down to 10 micro seconds > >> on a finishing burn. The Mesa 5i20 will create about 200kHz pulses with > >> L-cnc input and maybe one of the two parports on it could be repurposed as > >> a pulse generator? Maybe it's unrealistic to generate pulses from the > >> motion control PC because computing power isn't sufficient? Your > >> thoughts? > >> > >> Pete Gruendeman > >> > >> -------------------------------------------- > >> On Sun, 3/6/16, Nicklas Karlsson <[email protected]> wrote: > >> > >> Subject: Re: [Emc-developers] EDM gap control (Control parameters) > >> To: "EMC developers" <[email protected]> > >> Date: Sunday, March 6, 2016, 10:22 PM > >> > >> On Mon, 7 Mar 2016 > >> 10:23:31 +0800 > >> TJoseph Powderly <[email protected]> > >> wrote: > >> > >> > off time is > >> really dpendant on flushing conditions > >> > > >> on time causes rougher finer surface finish > >> > >> I guess this explain it all > >> and it also make perfect sense. More powder behind remove > >> more material and longer time in between leave more time for > >> debri to remove debri. > >> > >> > >> Regards Nicklas Karlsson > >> > >> > >> ------------------------------------------------------------------------------ > >> Transform Data into Opportunity. > >> Accelerate data analysis in your applications > >> with > >> Intel Data Analytics Acceleration > >> Library. > >> Click to learn more. > >> http://makebettercode.com/inteldaal-eval > >> _______________________________________________ > >> Emc-developers mailing list > >> [email protected] > >> https://lists.sourceforge.net/lists/listinfo/emc-developers > >> > >> > >> ------------------------------------------------------------------------------ > >> Transform Data into Opportunity. > >> Accelerate data analysis in your applications with > >> Intel Data Analytics Acceleration Library. > >> Click to learn more. > >> http://makebettercode.com/inteldaal-eval > >> _______________________________________________ > >> Emc-developers mailing list > >> [email protected] > >> https://lists.sourceforge.net/lists/listinfo/emc-developers > > ------------------------------------------------------------------------------ > > Transform Data into Opportunity. > > Accelerate data analysis in your applications with > > Intel Data Analytics Acceleration Library. > > Click to learn more. > > http://makebettercode.com/inteldaal-eval > > _______________________________________________ > > Emc-developers mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > ------------------------------------------------------------------------------ > Transform Data into Opportunity. > Accelerate data analysis in your applications with > Intel Data Analytics Acceleration Library. > Click to learn more. > http://pubads.g.doubleclick.net/gampad/clk?id=278785111&iu=/4140 > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers ------------------------------------------------------------------------------ Transform Data into Opportunity. 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