hello and welcome back to another
weekend projects in the pages of make
magazine I'm your host Kip Kay the
common ordinary light bulb we use them
all the time and never really give it
second thought well it might be a little
bit controversial but most people would
agree that Thomas Edison invented the
first electric light bulb well that may
be true he certainly was not the person
that invented the electric light that's
credited to a guy by the name of
Humphrey Davy who created an arc light
by using two carbon electrodes and then
applying voltage and then the small gap
in between those electrodes would
generate a very bright light well
there's a project in make volume 20 and
as you assumed it's Humphrey Davy and
the arc light and just by using some
common household items we're going to
build one today on this week's weekend
process
most of the things you'll need to build
the ArcLight
you can find at your local hardware
store you may even have some in your
garage the power source will be a
12-volt battery charger or 18 volt
battery you'll also need some copper
tubing a switch some alligator clips
porcelain insulators double-a batteries
nichrome wire and some heavy-duty lamp
cord our carbon rods are going to come
from some standard heavy-duty double-a
batteries these are non alkaline
batteries you want to make sure you get
non alkaline the best place for these is
a dollar store and the best way to open
up a double-a battery I found is to make
a slice in the label and remove that
just to get that out of the way and then
the positive cap should pop right off
now once you've done that I used a pair
of metal snips and made a small cut in
the edge and then basically started
peeling away at the metal housing you'll
eventually expose enough carbon rod that
it'll allow you to just wiggle it and
pull that carbon rod right out of the
battery now we'll need two carbon rods
so go ahead and cut another double-a
battery and then the carbon rods after
being cleaned off should fit snugly
inside your quarter inch copper tubing
you may need to either Sam the carbon
rod or grind away a little bit at the
copper tubing to get it to fit nice and
tight then we'll take a small file to
our carbon rods and file them to a point
the alligator clips that will hold our
carbon rods need to be a little bit
flexible so I took another piece of
heavy-duty wire and soldered those to my
alligator clips and put a little loop in
the bottom and then I screwed both of
those into a block of wood which will be
our base for our Arclight and attach the
copper electrode holders to the
alligator clips then I took a drill bit
that was slightly smaller than the
threads on the porcelain insulators I
got and drilled two holes in the front
of the block wood and installed the
insulators the purpose of the night
chrome wire is to provide some
resistance to prevent our 12 volt
battery charger from shorting out so
we'll run a couple of strands of that
across our porcelain insulators now your
length may vary depending on whether
you're using a 12-volt battery charger
or an 18 volt battery for this project
and be careful because that wire gets
very hot when we run it I attached two
pieces of wire to the spring clamped
alligator clips because they will make
contact with the alligator clips holding
the carbon electrodes and then ran two
wires to the heavy-duty switch which I
then installed in an old electrical box
just to give it some support when
turning it on and off so our main power
is the 12 volt battery charger and this
one has a 6 amp and a 2 amp setting I
went ahead and set it right up to the 6
amp setting and here is how everything
is wired up one wire comes from the
positive side of the 12 volt battery
charger and that goes directly to one of
the electrodes and then our arc will
jump across that electrode and go down
to our switch from the switch it goes to
one of our porcelain insulators and runs
across the night chrome wire and from
there it goes to the negative contact on
the 12 volt battery charger this barque
light produces very strong ultraviolet
light that can damage your eyes and your
skin so we'll be wearing a welder's
helmet and some heavy-duty gloves as we
test out our arc light now it's hard to
tell on video but this light is very
bright and by adjusting the nichrome
wire length you can increase or decrease
the intensity of the arc light now this
arc light is for demonstration purposes
only you don't want to run it for long
periods of time you could damage your
12-volt battery charger so that's how
the old lighting of the 1800s was
created using carbon and it's called an
arc light and we'll see you next time
with another weekend project