this is an esd wristband none of us want to blow up a board or a chip or even
test equipment which is why these are a staple in
any electrically sensitive environment but honestly i
hate them so today i'm going to make them better i hope
i'm actually pretty terrified to screw this up because i've never worked with
anything as fancy as what we're gonna work with before
and if i screw it up it's gonna get expensive but first things first
there are really three things that bother me about these
The first is that the cable
is simply obnoxious but unfortunately we're stuck with the
cable in a previous video four easy ways to blow up your test gear
we tried out and debunked wireless esd wristbands using a non-contact volt
meter even though they may be an excellent
mother's day gift or anniversary gift they
don't work as esd bands i'm really starting to doubt that amazon
description and unfortunately we are stuck with a
cord however there are two things that bother
me about these that i think i can fix first they aren't very
functional they're only good at the one thing but they don't really
do anything else second they aren't very fashionable
now i know that's not the first thing on your mind when you're wearing one of
these but they could at least try a little bit
so let's fix it we'll divide and conquer and try to improve the functionality
problem first so what's something that's super
functional but also cheap so i can get some practice
building my own strap i feel like it's staring me in the face
that'll do if this works it'll tell time and let me do some ohm's law
calculations on the fly but before we get building i wanted to
interrupt our regularly scheduled program and say that if you haven't
checked out keysight university you should go and do it now using the
link in the description and in the comments
we have tons of free engineering and test your courses that you can take in
under an hour and you get a certificate of completion
for your resume or linkedin profile i've personally put together many of
these courses and learned a lot from the ones i didn't create go check it out
at the link in the description also if you aren't subscribed to this
channel you should be where else on youtube would someone turn a rolex into
an esd strap
let's start with the calculator watch so i think this will be pretty simple the
first thing to do is pull apart an existing esd strap and see how it works
i'm also hoping to steal the cable and use it too so first we're going to
measure the resistance of the band and the cable so you can see the whole
system has about a 1 mega ohm resistance i'm curious also if it's in the strap or
in the cable or both so let's measure them independently on the strap i've
seen anywhere from half an ohm to 2 ohms so
really this is essentially just a short which means i should see about a
mega ohm in the cable so there's our mega ohm this is actually
really exciting because it means we can basically do whatever we want with the
watch and all the resistance is in the strap
we'll also dig into why it's a one mega ohm resistance at the end of the video
so what i want to do is take this little snap and solder it somehow to the back
of the watch conveniently the back of the watch
actually has a metal plate so it should be fairly straightforward
first though we have to sacrifice the strap to the esd gods
oh my gosh
oh my goodness i need some pliers i'm sweating
this will obviously be a montage
oh my gosh plan b this one seems a little more
fragile so i think i can flatten this out with a
hammer and solder that right to the watch back
like that
and won't be in business obviously don't try this at home
oh yeah look at that
like butter so this will go in here kind of like that
and solder to the metal on the back and how fashionable
is that make all the other kids jelly cause everyone knows i'm the pinnacle of
engineering fashion
so we have the watch back the est strap some flux
some solder paste a heat gun and we're gonna make this work
of truth
i used uh RoHS compliant solder paste oh no
three hours later
so after a fairly prolonged battle with the soldering iron and the heat gun and
flux and paste and solder it turns out it's really hard to solder stainless
steel so we are gonna try out a adhesive epoxy weld approach and we're
gonna see if that works and if it does we can call it a victory and move on to
our next build so the first thing we're going to do is scuff it up a little bit
with our rotary tool
not bare-handed
that should help it stick a little bit and then we're going to read the
directions on the clue
24 hours later so we left this to cure overnight and we haven't tested it at
all so i'm going to pull it off and we'll see
what happens
and that is surprisingly solid so we'll go ahead assemble it back up
and see what it looks like so it doesn't look horrible so get
that's a check for passable and on the street a
little cyberpunk maybe steampunk the next test is to actually
see if this will work as an esd band so i'm going to hook up
the clicker
oh no
um
um so we dremeled the living daylights out of this poor thing but
it turns out all we had to do was just bend the angle a little bit
and then they snap on perfectly so now all we have to do
is test it out and see if it works to test it out we're going to use this esd
tester you can get them on amazon they're like 20 bucks
they're not super expensive but if you're not grounded right now i have no
ground strap on and you hit the button it's going to
send a warning it's going to sound horrible however if
you are tested properly i have a actual esd band the normal esd band
works as expected no surprises there the real
question is is the calculator watch going to work
okay even with the angle still feels pretty good i can bend my wrist fine so
it should be functional for day to day this thing is basically trash added to
our pile of destroyed esd bans and cables and now
it's time to see if this is actually going to work
it works
so our beta test is complete overall i would say we learned a lot of ways to
not make a wireless esd band less rotary tools probably better for
the future but we have a functional calculator watch that is also an esd
band
it's still water resistant next we need fashion
i would argue that we have both function and fashion covered with a calculator
watch but some of you more boujee folks might
disagree the fanciest watch i own cost me a
whopping two figures so i set out to find a more fashionable
watch and that means the story time i put in a budget request for a used
rolex this is by far the most ridiculous
budget requests i've ever submitted i had to work up the nerve for it and
finally hit send on the email at 12 36 am
at 7 45 am that same day i got a response
my boss really didn't have to think too hard on it but it was worth a shot
after all now i can say i tried to expense a rolex to the company
so i had to get more creative and see if i could call in a favor
in another life at keysight before i started making videos i spent a week
over in asia visiting some engineering sites
and noticed that the person who hosted me was wearing a pretty fancy watch
that individual has since moved to colorado springs so
pre-quarantined i stopped by his desk to have a chat and i basically asked him
hey david do you have any ideas for a good watch for this video that we're
making and i kid you not the very next day he
walks up knowing what we're doing and he brought
me this
and that my friends is how you get your hands on rolex now if you want to help
me prove to my boss that they should have approved that expense request
go sign up for keysight university at the link in the description that's how i
get to keep making videos like this and you get to learn something it's a
win-win i've not actually looked up what this is
worth kind of curious now
wow so i got the calculator watch for about 20 bucks
this is roughly if i were to do the math
10 log 54 db more for this watch than this watch i
don't think i've ever mentioned dollars in db
now i'm honestly pretty terrified to play with this watch but
if it works it's gonna be legendary so to do this right
we're gonna have to get fancy not date night guys
to make this work without wrecking someone else's really nice watch i
picked up a genuine rolex watch band link to add on
it actually cost more than the calculator watch and we have to keep it
100 authentic or else it doesn't count based on what we learned with the
calculator watch soldering is not going to work even though i hoped it would
so we got a different welding glue solution that i think is going to be a
little more solid we're going to clamp it up leave it
overnight and see what happens
i really hope i don't screw this up
24 hours later okay this has been sitting for about 24 hours we're gonna
unclamp it see if we can get it on the strap and
have ourselves a rolex esd watch so let's see how it panned out just
popped right out
seems pretty solid looks acceptable for today let's add it onto
the link and see what happens it's worth more than my car
it's really a very simple task but the stakes are enormous
it looks beautiful i'm actually really it excited it was a little small before
so adding extra length was actually just right
the funny thing is the calculator watch may end up actually being a better esd
strap than this but we'll cover that in a minute
there's only one thing left to do though we gotta test it out and see if it works
so here it is with no cable not touching it
not good let's try it out can we get like more dramatic lighting or something
just to match how i feel right now perfect all right here we go
it works this is officially the world's most expensive esd strap
now i mentioned earlier that the calculator watch might actually be a
better strap and here's why the standard straps are expected to have
an internal resistance of less than 100 kilohms
so that you get a good connection to your skin for these builds i'll just
have a good connection already because it's metal and maybe i'll use some
lotion or something but here's where the rolex is
trouble the external resistance of the band should be greater than 10 mega ohms
so that you don't accidentally short your board
or connect to a live circuit if the strap hits it the calculator watch
has a resin strap so this isn't a problem but the rolex is conductive all
the way around which is really not ideal i'd recommend switching to a nice
leather strap or something like that if you were to go into the lab with it the
reason that there's a one mega ohm resistance in the cable
is that it limits the discharge current if you come into contact with an
energized conductor you don't want to damage your equipment or yourself
for a normal ac source like mains voltage the goal is to keep the current
less than half a milliamp however this isn't guaranteed protection
and you need to make educated safe decisions in the lab
these are all ansi esd specifications so to be safe
always use an approved esd strat and that's it for today
make sure to subscribe to this channel and if you want more videos like this
let me know in the comments and go check out keysight university
using the link below i'm daniel bogdanoff
stay classy or functional or both thanks for watching and i'll see you next time