Good morning Gents— and I use that term loosely ;) I’m trying to test out the basic premise of a reversing circuit. I’ve got a breadboard on the table here and I’m attempting to send a CCW signal from the BOB to a mosfet gating chip (2n7000) middle leg. It’s used to switch on the relay coil which in turn activates the DPDT switch of the relay. It no workie. The relay coil requires 12 Vdc. I have a diode between pins a and b of the coil otherwise it would immediately actuate the contacter. In theory this setup should work. I measured output voltage of the CCW pin @ 4.8 vdc high and when on an M3 it drops to .387 vdc. Essentially the mosfet holds the ground captive until the middle leg receives a signal (CCW) then it allows the ground to “source” and the relay should go “click”.
Not sure if any of this makes sense, it barely makes sense to me but the circuit was designed by an expert so I’m not going to question that, maybe my implementation. On Sat, May 9, 2020 at 1:15 AM John Dammeyer <[email protected]> wrote: > One of the greats in computer science has a series of interesting quotes. > https://www.azquotes.com/author/15849-Niklaus_Wirth > > One I really like is: > "The belief that complex systems require armies of designers and > programmers is wrong. A system that is not understood in its entirety, or > at least to a significant degree of detail by a single individual, should > probably not be built." ~ Niklaus Wirth > > I often wonder if LinuxCNC has reached this point. > > Although so far, Andy Pugh appears to be that single individual so I may > well be wrong. > > John Dammeyer > > > > -----Original Message----- > > From: Gene Heskett [mailto:[email protected]] > > Sent: May-08-20 9:44 PM > > To: [email protected] > > Subject: Re: [Emc-users] Fluctuating RPM using CUI ATM 10 encoder > > > > On Friday 08 May 2020 22:36:35 Dan Henderson wrote: > > > > > Thanks for the examples. I'm not going to lie, I've got some homework > > > to do on this. You guy's make this sound easy but to the new guy > > > looking in? No so much, lol > > > > Don't be glum Dan, you've already demo'd to me that you WILL get there. > > > > The fact that LinuxCNC is being further developed, literally as I type > > this, even if the basic premise is decades old, can't be emphasized > > enough. One of the reasons I posted snips of my old code, old but still > > after the new words were added to the hal recipe, was to demo that, far > > more than any finger pointing at Jon's example. If it works, its right. > > > > I apologize to Jon if it was taken that way. > > > > I cannot today even run that code, because the hardware under it has > > changed. For the better is an arguable point because that driver Jon > > makes is a no compromise device doing exactly what you tell it to do > > with zero drama. It can now make that same motor break all sorts of > > stuff between it and the chuck it spins if I hadn't taken measures to > > tame the violent acceleration that drive is capable of making it do. > > OTOH, that 1 hp rated motor can now deliver nearly 2hp because the psu I > > built out of junk box parts makes 35 more volts and 10x the current that > > cleared the fuse in the OEM configuration. But it also gets the job > > done. Its had stuff in that 5" chuck that weigh half what that whole > > lathe weighs, and made the part. > > > > [...] > > > > > > Yes, I'm pretty sure it still does. But, yes, this is OLD > > > > STYLE hal code, for sure. > > > > You can combine any newsig / linkps / linksp into one net > > > > command, with > > > > > > > > net signal-name pin pin pin ... > > > > > > > > And, you don't have to tell it the signal type, it gets it > > > > from the first pin. > > > > > > > > Jon > > > > > > > > > > Cheers, Gene Heskett > > -- > > "There are four boxes to be used in defense of liberty: > > soap, ballot, jury, and ammo. Please use in that order." > > -Ed Howdershelt (Author) > > If we desire respect for the law, we must first make the law respectable. > > - Louis D. Brandeis > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
