Do these grounded wrist straps slow you down and chain you to your bench?
Where's my coffee?
Static electricity. It's good for more than just blowing up your device
under test. You can also use it to blow up your test gear. What fun!
Hi, I'm Daniel Bogdanoff and today we're gonna look at four easy
ways you can blow up your test gear with ESD or the wrong inputs. It happens to
people all the time. Don't believe me? Just ask a repair department who may or
may not have asked me to make this video or the opposite of this video. I don't
remember. When they asked me to make a static video I told them that's
literally just a picture and the whole conversation with downhill from there.
Anyways electronic damage to test gear is caused by an excessive amount
of power going into an equipment's inputs and that power gets there in a few
different ways. If you want to blow up your test gear follow these tips.
Before we dig in we have a free checklist you can download that covers each of these
tips so you can have a memento of the time we're about to spend together.
Even better, subscribe to this channel and we can do it again sometime,
or if you've already subscribed give the video like and we can keep this thing going.
And, finally we have three extra bonus
tips at the end of this video so make sure to watch the whole thing.
Without further ado here's tip number one.
The easiest way to blow up test gear is to
hook up just any ol' signal without knowing its characteristics. Sure a test
gear's datasheet lists the maximum input parameters and sure equipment has
built-in protection mechanisms and will often warn you if you're about to go
outside the spec and sure we even print the max input rating on the gear right
next to the inputs but one simply cannot build a sensitive measurement device that
can also take any input safely. That piece of testier doesn't exist. And you
can even damage your equipment without ever seen a warning. The responsibility
to protect your gear is on you. So I have this 12 kilovolt neon sign
transformer and there's nine volt battery. One of these is a safe
input and one of these is not. Let's figure out which is which.
Let's start with the twelve kilovolt neon sign transformer.
Actually I'm just kidding, I don't want to die, and
and more importantly I don't actually want to blow up my
equipment. To avoid blowing up your equipment this way
don't exceed the maximum input power or voltage on your gear. Also when
connecting to an unknown signal start at the lowest sensitivity and work your way
down to the signal. Essentially you always want to keep your signal
completely on the screen. But did you know you can also expose your equipment
to ten kilovolts or twelve kilovolts quite easily without the help of this
death transformer? Here's how.
You've probably heard the phrase "treat yourself"
but if you want to blow up your equipment it's time to "float yourself."
Throw caution to the wind. If your feet aren't buried in wet sand at the beach
or your wrist isn't shackled to a properly grounded ESD mat, odds are your
high voltage which is the perfect way to blow up your test gear. I can charge
myself up just by walking around and then we can watch this charge transfer
into the board. If I'm grounded it doesn't happen.
Do these grounds and wrist straps slow you down and chain you to your bench?
Well if you want to blow up your test gear, you can just take it off or you can get one of these cheap,
wireless, anti-static wrist bands like I did or get six. I think six will work better.
Or if you're classy like me you can get a fancy wireless anti-static band.
Because it costs more than one of those corded bands it must work better right?
According to the seller's description these can even make a nice anniversary gift.
I'll let you know how that works out for me.
As you can see with our ESD meter an ungrounded person or person with a wireless ESD Band can have
charge. The charges then transferred right into the equipment or to an
ungrounded conductor. Then when this board is connected to equipment it can
damage the gear. Trust me, at the end of the day not using protection will have
unintended, long-term consequences.
So go ahead handle your gear without proper
ESD precautions but to avoid damage make sure your mat is properly grounded and
use corded ground straps. Mats can be grounded via a ground connection on the
instrument which is preferred or through a ground cube plug or the ground screw
on an outlet. Make sure your ground wire won't accidentally touch to hot also.
I should also point out that it only takes a couple hundred volts to damage some
gear but you only feel it when you're well
above 1 kV. Granted this is an obvious way to do damage but the next few might
be new to you and are all related to static field induction.
If you aren't careful your boards can charge up via induction and then zap your gear.
Take for example this cart. It's pretty common for folks to need a little extra bench
space and put the board and gear on an insulated material like this. But watch,
if we jiggle the cart around a little bit or just give it some of the positive
reinforcement it so desperately needs-
Good job, cart. Way to be, cart. Yeah cart!
It charges up.
In this case its charged up to well over 10kv.
When you put your board on it the charge equalizes and normalizes so they
both end up charged thanks to induction. Your body can also charge up and
transfer that charge to your board then you innocently go to hook up your charge
device to your test gear and boom. Then we'll do a little explosion or something.
Imitates explosion noise.
So Tip 3 for blowing up your test gear is to use an insulated or high
resistance material as a platform for your interface boards and devices.
It's not just big carts like this either, all kinds of high resistance materials build
up an electrostatic field. Using our handy electrostatic field meter we can
see that this material charges up to over a kv. You don't want that going into
your test gear. To avoid this damage keep charged materials at least a foot away
from your boards and use appropriate materials. If you're transporting boards
you should also completely seal them up in static shielding bags so they don't
charge up during transport. It's not just boards you have to watch out for though,
your cables can also cause damage.
Believe it or not the center conductors of your cables themselves can build up a charge through induction from a board or
surrounding fields. Remember this from last tip? This is bad bad thing to do.
So to blow up your test gear just grab a cable at random and connect it up to
your gear without discharging it first. If you want to avoid this damage you
should first discharge your cables before using them and here's how you do that.
First make sure your device is not
powered. Second connect one end of the cable to your device. Then grab the other
end of the cable and connect it to a 50 ohm shunt or you can use a short in a pinch.
This connects the center conductor in the outer shielding effectively
discharging the center conductor. Finally remove the shunt and immediately connect
up to your test gear. And there you have it four easy ways to blow up your test
gear however because we're a little bit extra sometimes here are three super
quick Keysight bonus tips for keeping your gear safe.
Sometimes you need to be extra cautious especially when working with exposed assemblies.
A good ESD mat has a resistance in the ten to the eighth ballpark which is
often pretty good insulation but if this isn't enough use stand offs
to keep your board off the mat. This lets an air gap be your insulator and
ensures that you're exposed board assemblies don't have any unexpected
paths to ground. Who knows what fun that could cause.
Pink packing material pretends to be static safe but often it's not.
To be safe, simply don't use it for your boards and instead use ESD approved mats, standoffs
and packaging. We grab these three random pink foam pieces from around the
building here and you can see in our meter that they each have a charge it's
potentially damaging and the charge on these is all different.
if you aren't using a channel, cap it. This helps avoid incidental contact that could lead to
ESD trauma. Now obviously you don't want to blow up
your test gear so we've put together a handy free checklist that you can throw
up on your cubicle wall as a reminder of what you should be doing. There's a link
for that download in the description but it all comes down to the fact that
equipment is damaged by excessive input power. Avoid it at all costs. Stay within
the rated input range. Use a grounding mechanism for yourself and your work
surface. To be extra safe use a little checker like this to make sure you're
grounded before handling anything on your bench and finally handle boards and
cables properly. This means keeping charged materials at least a foot away
from your boards, using standoffs, proper materials and proper discharging
techniques. Thanks for watching! Make sure to subscribe to this YouTube channel,
download the free ESD checklist and put your worst ESD story in the comments so
we can commiserate with you. I'm Daniel Bogdanoff and i'll see you next time.
Good cart. You're doing such a great job. Good job cart. Way to be, cart. Yeah cart!
okay