 the game here so here we are dealing with this is a basic schematic basic motor control schematic you've got a stop button right here I've got a start button right here I've got a relay coil right here now relay coil is the actual thing that pulls it in and I'll show you what that means in a second here so this is the actual electromagnet now with this relay it also has sets of contacts associated with it so I have a set of normally open contacts here a set of normally open contacts here and a set of normally closed contacts here so the way this circuit works is right now if there's control power coming in on the top I got power coming through goes through the stop button gets to the start can't make the jump goes to the normal open contact can't make the jump I've also got current going down here can't make the jump to the green light however it can go through the normally closed contact so my red light will be on so this is a circuit actually had my class wire up on Friday so it's kind of they get all excited about it I get excited about it still and I've been teaching this for almost 10 years now so what happens now is when I go to hit the button I push down this button here my star button which will energize this coil which is that electromagnet and I'll show you what I mean by that in a second when that energizes all the contacts that are physically attached to this guy are gonna do what they're supposed to normally open is gonna close so what'll happen here is I push that button down that energizes these clothes and now my current can go through there and keep this guy held in because when I let go of the push button it pops back up so if I didn't have this set of contacts here this would energize only as long as I press this down now that I have this set of contacts I press it down energizes pulls in let it up I still have a path that my current can go through and energize my relay same thing down here this set of contacts will be physically attached to this so it'll close and my green light will go on this is normally closed which means when this energizes these open and my red light turns off and that is as basic circuit as you can get as far as a relay is concerned but and you know what motor control circuits work the same way except the only difference is you've got a coil an M coil we call it but you also have a set of overloads and maybe if you guys want I can probably throw together a little mini lesson on how a motor contact or not a motor contact or motor starter works and then I'll bring a demo in and I'll show you guys how that all plays out so that is my basic relay circuit now when I talk about a relay this is what's on the inside so let me just pop this guy out here so you can see here that I've got a coil that is my electromagnet and inside here you can't really see inside but I've got a set of contacts in there as well when I look at this here this is my coil I'd have two wires coming here like an a1 and an a2 I energize this coil here which in turn turns this whole core into an electromagnet can we dig it so that's what's happening with this so this becomes magnetized when I bring power to it this is your armature so what it is is some ferrous material magnetic material a material that would like to become magnetic and it's going to pull up because it's attracted to the electromagnet here okay so that's how the the coil part works now up here is where our contacts work and this here would be a set of normally closed contacts I've got contact here a contact here and it goes through contact contact so my power is always going through here boop up top here I have normally open contacts because I've got no place to go and the other side is waiting to get some power as well so we're going to energize this in a second here so again this becomes magnetized this armature pulls up this whole assembly pushes up so what's going to happen is this side is going to break and this side is going to make let me show you what I mean there we go this right here so I've got this energized see how this pulled up the armature the whole assembly moved up and here where it was once normally closed is now open in which was once normally open is now closed that's how all your relays work except for solid-state relays but all your electromechanical relays they all work on the same principle your motor starters they work on the same principle you've got a core here you've got an armature you got a set of contacts now I only have two sets of contacts here you can have way more which is the whole purpose of this 8 pin and 11 pin relay which we'll get into in a second okay so that's how that's happened now for the 8 pin and 11 pin relay let me just call this up here we go back to make sure I got this sharing of the screen happening one second here just download there we go I have my 8 pin relay here so I've got 1 2 3 4 5 6 7 8 and if you look at it right here I got my 8 pins it's a circular thing but I have all these connection points along here all those are our different points here now if I look at this guy if you look close there's they're all numbered 2 and 7 so this 2 here and this 7 here that is my coil so that's the power that energizes my coil so that's important we need to bring power there to have the magnet pull in when I have a set of two sets of contacts here sorry not when I I do have two sets of contacts here I've got one set this number one we call that a common because power is coming in here now power can either go from one to four which would be normally closed or one to three which is normally open so I have two sets of contacts here and one common now the thing is and the the one that I showed you let me just back up the truck here this guy is that read the point there I got normally open sorry I'd be back it up one more normally open set of contacts normally closed set of contacts normally open set of contacts right there normally closed set of contacts right there I might require more contacts that's where the 8 pin is handy I've got another set of contacts down here I got my 8 which is my common and then my 8 to 6 would be my normally open in 8 to 5 is normally closed which makes it useful now if you need even more contacts that is where the 11 pin relay comes in boom all it is it's just another set of contacts down here so it gives you three full sets of contacts the difference is the wiring is a little bit different for the coil your two in your 10 is now your coil and then you just go one to four is normally closed one to three is normally open 11 to 8 is normally closed 11 to 9 is normally open 6 to 5 is normally closed 6 to 7 is normally open 3 sets of contacts and then beyond that you can probably get even higher I don't think I've ever used anything more than three sets of contacts but it's something you'd might want to consider I guess if you're looking into it now how do I know all this where did I get all these sets of contacts from on the relay itself there is a drawing or drawing and the problem with the drawing sometimes as it gets rubbed off or you can't read it that well or as you get older you're having to hold it further and further apart but you can see all that in there all I did was take that and then translate it onto there so everything you need is on the relay itself also you need to be careful that you're using the right coil voltage not all coils can take every single voltage you need to make sure that if you have 120 volt control circuit that your coil is rated for 120 volts it's rated for 240 it's not going to pick up if it's rated for 24 you're going to blow it up so that's something to consider as well