Spider's power switch - Electronics and Communication Engineering Video Lecture - Electronics and Communication Engineering (ECE)

In this video, we're going
to connect the power switch
and run the power wires to
the L298 motor controller.
So we've got our
power switch that we
made in a previous video.
And you can see how we have
a long wire and a short wire.
So the wires from the battery,
we're going to twist together.
So we have two red wires, we're
going to twist those together.
We're wiring the
batteries in parallel,
because we want to keep
the voltage the same
but increase the amount of
time we can run the batteries.
So we're going to twist
those wires together
with the short battery
wire-- or with the short wire
from our switch.
And so we're just
twisting those together.
And once we have them twisted
together very tightly,
we'll take our soldering
iron, which is already hot.
And we'll warm the wires up, and
then put a little bit of solder
on them.
And that'll help to make sure
that they stay completely
together.
That will just keep the
wires held together.
OK, so then we're going to
trim off the excess there.
And we're going to use some
shrink wrap tubing on this.
Now you may not have a shrink
wrap gun or the shrink wrap
tubing.
So if you don't, you can also
just use electrical tape,
and tape it around it.
The shrink wrap tends to
hold a little bit better.
But it means that you have
to have the shrink wrap
gun, so it's a little
bit more cumbersome.
But in any case, you can take
just black electrical tape
and wrap it around, and
it'll do the same thing.
So we've got our
heat shrink gun,
and we're shrinking that
heat shrink tubing over that.
And again, that's just
to basically prevent
the bare metal from touching
anything else and potentially
causing a short or a problem.
So we want to make sure that
all of the exposed wires
are covered or insulated.
All right.
So now we've got our
switch, and we're
going to take some
hot glue, and we're
going to put it over
all of the contacts
on the back of our switch.
And the main reason for this
is that usually the switch
is on the bottom
of the tap light,
so there's no
chance for anything
to touch those
electrical contacts.
But because it's not on
the bottom of the tap light
anymore, it can bump up against
something that's metallic.
And that means that the switch
could potentially short out.
Or the electricity
could be conducted
through a different part of the
circuit in a way we don't want.
And that could cause
problems for us.
So now that that hot glue is
dry, the back of the switch
is protected and insulated
by that hot glue.
So now we can take our
long wire from our switch,
and connect it to the
port-- on our terminal
block I should say, on
our motor controller.
That is meant for
the positive wire.
So what we're going
to do, is we're
going to take the
long wire, and we're
going to put it in on
the terminal block that
is on the far left-hand side.
So it's really important
that it goes on that one.
Now it's also very important--
this is a little too long,
so we're just going to trim it
down just a little bit there.
And again, it's important
that we have just enough wire
to make the connection, but
no extra wire exposed there,
because we don't want it to
touch another metal piece.
Now it's important that that
red wire, the long red wire,
goes to the far left
terminal block when
it's set up in this orientation.
That's where the
positive 9 volts comes in
from the battery.
OK.
So now we're going
to make another--
we're going to take
two more wires.
We've got one wire that's about
2 and 1/2 inches long, 3 inches
long, and one wire that
is about 5 inches long.
So we're just stripping
the ends off of those.
And again, we're trimming
our battery wires now,
getting those ready
to connect together.
So these are the negative,
or the ground wires,
from our battery.
We want to make sure we
pull off the insulation.
Sometimes it can be
tricky to get off there.
These wire strippers work
really good for solid core wire,
but this is a stranded
wire from our battery,
so sometimes it causes
the wire to break.
So you have to be
kind of careful there.
In any case, we've
got our, we're
going to take a little bit
more, expose a little bit more
of the wire.
So it's closer to 3/8 inch.
We're going to twist
those two wires together,
the two black
wires, and those are
going to be our negative wires.
And then we're going to twist
those with the two black wires
from our battery.
All right, so we have a
nice solid connection there.
And again, it's just
kind of like what
we did with our switch wire.
And once we have those wires
solidly connected together,
we're going to take
our soldering iron.
And again, we're going to try
and get the solder to wick
through the recently
twisted together wires.
And once the solder flows down
all the twisted together wires,
we will have a nice
solid connection.
So we're going to trim
off the edge of that wire.
OK, so once we've got
the wire trimmed off,
we're going to take our
pliers and squeeze the solder.
And just make sure that
it's nice and smooth,
so that we can get it to fit in
the center pin of our terminal
block there.
That's our 3 pin terminal
block in the front.
And we can get it to fit
snugly, and then we're
going to take our screwdriver.
We're just going to tighten the
screwdriver down, or tighten
that pin down.
And we'll take the long negative
wire and bend it to the back.
And the short one we're going
to strip off about a 1/4 inch.
And we can sort of keep
that exposed for the front.
So now what we need is,
we're going to take our 5--
we're going to take, I'm
sorry, another wire that's
about 3 inches long,
this is a red wire,
and strip off about a
1/4 inch of insulation.
And we're going to connect
it to the terminal block pin
on the far right,
the 3 pin terminal
block on the far right.
And that that's
going to provide us
5 volt power for our Arduino.
So we'll connect
that in a second.
But for now, let's
connect our, we
need to connect our
header pin jumper wires.
And so we have four female to
female header pin jumper wires.
There's one, two, three, four.
And we're going to connect
those to our header pins
on our L298 board.
So we're just going to
slide those down on all four
of those header pin ones.
It doesn't matter
which one goes where.
And once all of those are
connected to our 4 header pins,
we are going to be ready
to connect our Arduino.