On Wednesday, 11 May 2022 16:19:58 EDT Peter C. Wallace wrote: > On Wed, 11 May 2022, gene heskett wrote: > > Date: Wed, 11 May 2022 16:13:58 -0400 > > From: gene heskett <[email protected]> > > Reply-To: "Enhanced Machine Controller (EMC)" > > > > <[email protected]> > > > > To: [email protected] > > Subject: [Emc-users] Do pnp prox switches need a pulldown load R? > > > > Greetings all; > > > > Peter in particular, > > > > This is my first try at utilizing a prox switch, and while the led on > > it responds just fine on 12 volts, I measure around 6 volts on the > > blue wire when its off, and only 7.1 volts when its fired. With > > +12.0 volts on the red wire. These are "PNP" switches. > > > > So I'm assuming my 10 meg meter is not enough load to pull it down > > when its off. So what value of loading R to common is needed to make > > it properly register to a field input of a 7i76 useing a 12 volt > > field power src? > > > > Is that 7 volts enough to make a field input reliably see a logic > > one? > > > > Thanks all. > > > > 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, 1940) > > If we desire respect for the law, we must first make the law > > respectable. - Louis D. Brandeis > > > > > > > > > > > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > Sounds faulty or mis-wired > > It should be very close to 12V in the high state > > (off state probably does need a load)
I bought 10 of them, the first 3 act quite similar, drawing way more than the led needs when fired, and nowhere near 12 volts on the blue wire when fired. Only dropping a volt at most on the blue wire when the led is out and current is too low to even estimate on a 5 amp FS meter. So I have a batch of bad ones, or I'm misswireing them in a manner that still makes the led respond normally. And according to several diagrams I looked up, the blue wire is the - leg, and the black wire is the outout. I wonder what color blind $GENIUS invented that? No wonder its getting hot when fired. I'll retest these 3. Wired blue for negative, they work fine. black=output, Off is zero volts, on is 11.3. Even the led is brighter. So now its public record that I'm an idiot. When I grew up, sorta, mid teens and started fixing the neighbors radios in the late 40's, black was ground return for everything. Grrrrrrr. Thanks Peter. Take care, and stay well. > Peter Wallace > Mesa Electronics > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > . 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, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
