EEVblog #279 - How NOT To Blow Up Your Oscilloscope!

How NOT to blow up your Oscilloscope.
Your oscilloscope ground clip lead can be a potential accident waiting to happen.
Why? And how do you avoid it?
The basics about safety and measuring mains earth referenced equipment with your oscilloscope.

#Oscilloscope #Danger #Tutorial

[LuisAntolin]

Very useful. As a newbie, I see a 99% chance you saved my scope. Thanks for that.

[Shaker-Hamdi]

12 years later, and still the best video to explain this. Very very very nice video.

[techsguild]

Learned more in 20 minutes here then 3 months in class, lol. Thank you.

[stevetobias]

Thank you so much, have just purchased my first oscilloscope and I am a hobbyist teaching myself. I learn so much from people like you and am grateful you share your valuable knowledge.

[SeaJay_Oceans]

This should be lesson #1 in every electronics class !Safety First - thank you for a great explanation. You are Saving many fingers & expensive equipment !

[NoName-dcrn]

Our professor made us watch this exact video in my intro to EE class before we were allowed to use oscilloscopes. It feels weird stumbling on this video a few years later.

[hbirtt]

Thank you from 6 years in the future Dave. I've heard several times how hooking a scope up "incorrectly" can kill it, but that's usually where people leave it, so it's been in the back of my mind "what magical connection will kill my scope and blow my house up?" I've never taken the time to figure out what this scenario is. Assuming there is no other odd scenario, and it just comes down to "don't create a jumper wire with your house ground network, " it's common sense, but now that I know what people where talking about, I feel better. I can definitely see someone, including me, not paying attention and doing exactly this (especially with the USB scenario), but there's no hard to identify demon in my circuits waiting to kill me.

[matteocassino]

Even years later it is still valid stuff you can learn here. It looks to be really a good idea to watch this first before taking my brand new oscilloscope at risk. Thx Dave for this great lesson.

[tomkirbygreen]

Thank you for this, about to buy my first scope, a DS1054Z, and busy learning the basics. Material like this is hugely valuable! Kudos.

[donmoore]

My dad taught me this with his Heathkit O-11 oscilloscope decades ago. I haven't used a scope in several years, but that lesson sticks with me to this day. I'm getting back into electronics and a Keytronics scope is being shipped to me, and was curious if the probe grounds are still earth ground - looks like they are. Important topic - you're doing great work!

[CappellaTheCat]

Just blew up my Creative Tactics Sigma headset usb adapter... I was measuring with my Rigol DS1054Z the output of a class D amplifier (~50Vpp)... output, input was from mobile phone (floating) and signal was not enough to reach full amplifier potential, so I connected the input to the USB adapter of my headset.... big mistake... Oscilloscope is fine, PC USB port is fine, usb adapter has its case slighly melted on one side, 1 compoent has vaporized along with 1 layer of the PCB, one inductor is burnt and another capacitor seems burnt as well... the 3.5mm jack cable from usb adapter to amplifier was very hot... I knew it, I watched this video before, but I did the damn mistake again... Stupid me... Remembered this video and shared it on Facebook... Mistakes are so easy to make...

[steve-maheshsingh]

This was the best 24 minutes and 23 seconds of Internet time have ever spent.. Thank You for this!

I just got my first oscilloscope and I did not know this. You may have saved me a bad day. Thanks.

[PilotPlater]

Was probing a shunt resistor on the positive rail of a small electric car one time, and I wasn't worried about it because the car is on rubber tires and is battery powered by two car batteries so it should be isolated from mains.

Joke was on me though, because here I am sitting in the seat of the car with the scope outsides sitting on the bench, some of the wires across my lap, when the car rolls back a few feet. Wouldn't have been a problem, but it just so happens that part of the shop I was working in has metal paneling on the wall for the first few feet above the floor.

SURPRISE, that paneling is grounded, and so is the scope. All the wires between me and the scope light up BANG! The car hadn't had the fibreglass body put on it so the bare metal frame touching the paneling made a dead short across the 24v car batteries.

It took me like an hour to figure out why the heck it lit up!

[mearslab]

FANTASTIC video! If I could hit like 100 times I would, I've searched on the internet to no avail for a simple yet complete explanation like this.  This covered exactly what I was hoping to learn.  Thank You!

[Me-tuber]

"Please excuse the crudity of this model, I didn't have time to build it to scale or to paint it…" haha you are the best teacher around !

[elliec]

Just proves that a little knowledge is dangerous. As a newbie to scopes this was a great foundation course. Thanks muchly.

[chuckhursch]

I managed to short through one of the probes of my scope about 15-20 years ago. Still remember the bang! Have been very leery of scopes since then, but have come around to understanding what’s going on. This video clarifies what I have concluded. Might even pull out my scope sometime and see if it is (un)damaged - I never really used it again after that.

[whitefields]

Dave, back to basics, thanks for keeping us all grounded

[lynnhilborn]

Another connection to avoid perhaps would be, when using an isolation transformer on a radio under test and then attaching a coaxial antenna to the rig. In my shack the outer shield of the coax is both grounded for rf and is tied back to the service entrance ground. In this case we have defeated the isolation transformer.