Hi Robin, I would do that if the manual didn't say the boards are ready for inductive loads (and now Peter ratified that too) or if I'm too close to the max current threshold. But I really want to keep this as simple as possible at this final stage. I was worried because I was used to solenoids that draw 300 mA maximum, but these valves I purchased are a little bit more hungry.
Thanks for the advice and stay well! El dom, 15 may 2022 a las 21:55, Robin Szemeti via Emc-users (< emc-users@lists.sourceforge.net>) escribió: > Personally, I would wire up some external driver simply to avoid any > accident with the 7i72 ... optos would be involved if it was me. > > On Mon, 16 May 2022 at 01:27, Peter C. Wallace <p...@mesanet.com> wrote: > > > On Sun, 15 May 2022, Leonardo Marsaglia wrote: > > > > > Date: Sun, 15 May 2022 20:59:34 -0300 > > > From: Leonardo Marsaglia <ldmarsag...@gmail.com> > > > Reply-To: "Enhanced Machine Controller (EMC)" > > > <emc-users@lists.sourceforge.net> > > > To: "Enhanced Machine Controller (EMC)" < > emc-users@lists.sourceforge.net > > > > > > Subject: [Emc-users] 7i72 max output current question > > > > > > Hi guys, I hope you're all doing great > > > > > > This could be probably for Peter but most of you will know the answer > so > > > here it goes. > > > > > > I have to drive some 24 VCC pneumatic electrovalves and I would like to > > use > > > 7i72's outputs directly. Each valve consumes 400 mA and the 7i72 max > > > current per output is 300 or 350 mA. But, the short circuit protection > > per > > > output is triggered at 800 mA. So I was thinking in two possible ways > to > > > drive the valves: > > > > > > 400 mA per output should be OK unless you have mode than 3 outputs on at > > once > > per chip (the cards are tested at 500 mA) > > > > Do make sure that the solenoids have flyback diodes > > > > > > > > > > 1- to accommodate one valve per output (without exceeding the 1.4 amps > of > > > max current per output chip) and hope the 400mA are not too much for > the > > > overcurrent monitoring. > > > > > > 2- to drive every valve with two consecutive outputs to divide the > > current > > > in half so every output would only see 200 mA (again without exceeding > > the > > > max current per output chip). > > > > > > What do you guys think? I'm trying to avoid to install any extra > > circuitry > > > if possible. > > > > > > Thank you as always for your help! > > > > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > Peter Wallace > > Mesa Electronics > > > > (\__/) > > (='.'=) This is Bunny. Copy and paste bunny into your > > (")_(") signature to help him gain world domination. > > > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
