About this video
The narrator fits the L298 motor controller into the bezel, glues it centred on the base using a marked outline, and wires the two motors to its terminals. He stresses stripping only about an eighth of an inch so the positive and negative terminals cannot touch.
You'll be able to
- explain why the motor controller must be centred on its marks.
- state the correct amount of insulation to strip from motor wires.
- predict what happens when exposed wire touches the other terminal.
Key words
- Bezel
- The original ring from the tap light that fits around the motor controller to hold it in place.
- Heat sink
- A metal part that draws heat away from a component, here the motor controller.
- Hot glue
- A thermoplastic adhesive that sets as it cools and secures components to the base.
- Short circuit
- An unintended connection between terminals that causes current to bypass the load.
- Motor mount block
- A terminal block with screws that holds motor wires in place.
Transcript
So in this video, we're going to show you how to connect the L298 motor controller to the base. And we're also going to show you how to wire the motors to the motor controller. So the first thing we need to do is we're going to put our bezel around it. And this is part of the original tap light.
And that'll kind of-- we just want to make sure it fits and see how the L298 fits in there. And it's a pretty snug fit, so it's important to get a sense for how the bezel's going to go around it. We want to make sure everything is centered. So once that's centered and set up right, we're going to take a pencil-- and if you have a pen or whatever, anything you have to mark the edges, that would be great.
I found that a mechanical pencil works well because it's easy to get around the edges. So you can sort of see the faint outline that I've drawn there. And that's going to allow us to make sure that the motor controller is in the center. So we're going to put about a quarter-size blob of hot glue down.
And we're going to put our motor controller right on top of that and line it up with the marks that we've just made. Now, it's really important that we line that motor controller up with those marks. If the motor controller is shifted to one side or another, the bezel won't fit over the top in the right way, and so it won't look right, and it won't fit together quite right.
It takes a while for that hot glue to dry and to cure, because there's a lot of hot glue there, so there's a lot of thermal mass. And it takes a while for it to cool down. You can actually feel the heat sink, which is the part that my left hand is connected to.
You could feel the heat sink getting warmer, because it's transferring some of that heat from the hot glue up. So once the hot glue is in place and the L298 is firmly in place, let's double-check and make sure that the bezel still fits on over-- around the wires and the L298.
Now remember, there's a bunch of different connections on the inside of that bezel, so you might have to rotate it to get it to fit. So in any case, that's basically how the bezel's going to fit. And we've got everything the way we want it, as far as the L298.
So now what we're going to do is we're going to trim down our motor wires. These are the two motor wires here. We're going to connect those to one side of our L298. And then we'll connect the other two motor wires to the other side of L298 motor controller. And just right there.
And what we'll do is we're going to strip off a little less than a quarter, about 1/8 inch of insulation off the edge of the wire. And once we've got that insulation stripped off of both wires on both sides, we can go ahead and then start attaching those wires.
And you don't need to strip off a whole lot of insulation. It's actually important that you strip off only about 1/8 of an inch, maybe just a little bit more, 3/16 of an inch. Because if you have too much exposed wire, the positive and negative terminal could touch, and then they won't work-- the motors work appropriately.
You'll get a short. OK, so we're going to loosen our screws on the motor mount connection there. And then we're going to put our two motor wires in. And we'll tighten those screws back down. And that's going to hold those wires in place. And notice, there's no exposed wire.
It's just insulation coming out of the motor mount block there, the motor block. So we're tightening that down. And then we're going to put our other wire in there. And you can just sort of push it to the side if it's a little too long. OK, so that's about it.
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