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. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
