You might consider putting an "emitter follower" circuit at the output of your circuit. The NPN Darlington configuration might be appropriate. http://images.google.com/imgres?imgurl=http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/ietron/darl.gif&imgrefurl=http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/emitfol.html&usg=__YsP5vDTSAyH1_LgPZsUd4Kj7csk=&h=256&w=248&sz=2&hl=en&start=6&um=1&tbnid=9O8nEjwky6glcM:&tbnh=111&tbnw=108&prev=/images%3Fq%3Demitter%2Bfollower%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DX%26um%3D1
Ken Kirk Wallace wrote: > On Fri, 2009-06-26 at 14:52 +1000, Frank Tkalcevic wrote: > >>> (Other good news/bad news. I blew out the serialDAC, but had >>> a spare chip. I'm looking for advise on how to protect the >>> output op-amp: >>> http://www.wallacecompany.com/machine_shop/EMC2/serial_dac/ser >>> ial_dac_sch.png >>> > > Oops, looks like I missed the link wrap. Here is a short URL: > http://preview.alturl.com/9qo4 > > >> I'm not sure if this is what you are looking for, but there was an example >> circuit to opto-isolate analog outputs posted on the gecko yahoo group, in >> Files/G100 and G101/G100 to VFD.zip. It contains a pdf schematic, as well >> as gerber files. Full link here... >> >> http://f1.grp.yahoofs.com/v1/wEdESqlRISAvXS1kqNpUyHreATzPsS6fyvPYjIkwCrzxcP5 >> sN-O39ow1eZON1_k89sEXfl4jj18PJjRgWEkX-UyxFYezazMt/G100%20and%20G101/G100%20t >> o%20VFD.zip >> > > Short URL here http://preview.alturl.com/8hm6 > > Thanks for the link, Frank. I wish I were better at electronics, then I > would know what this circuit does. It looks like the op-amps only have a > 10kOhm resistor on their outputs, which would limit the current going in > or out of the amp. This may offer current protection but maybe not > enough voltage protection. I was thinking of putting a 12 volt Zener > between the op-amp output and the output ground, but I don't know if > that is a good idea or not. I suppose I could just try it and see what > happens. > > It looks like the above circuit takes in an analog input, converts it to > PWM or PDM, then back to analog on the far side of the opto-isolator. I > wonder how fast it is? A VFD signal might not need to change quickly, > but an analog axis servo would. > > >>> I also got my ATtiny2313 programmer and proto-board working, >>> but blew both 2313 chips I had on hand the first day, with no >>> gratuitous smoke either. I'm looking for a 2313 simulator >>> that will run on Ubuntu so I can test programs before I try >>> to program real chips.) >>> >> I only know of AVRStudio for windows, but I find that it's simulation is >> pretty ordinary. I was simulating the 2313 a while back and it was missing >> a timer. Maybe it was just a bad install. >> > > I don't have any Windows machines so I would have to set up Wine to run > AVRstudio, but it may be worth it, if I can save some burnt chips. > > -- Kenneth Lerman Mark Kenny Products Company, LLC 55 Main Street Newtown, CT 06470 888-ISO-SEVO 203-426-7166 ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
