Easy DIY passive #probe to measure #mains with the #oscilloscope

Do you have to measure mains voltage waveform just once in your whole life? Differential probes are too expensive? Here it is a simple, cheap, DIY solution.
CAUTION: Working on mains voltage is dangerous, you MUST know what you do.
Directly using the probes of the oscilloscope to measure the mains is hazardous, it could lead to from destroying your probes to melting the traces of the PCB inside your oscilloscope, not to mention the risk of being injured. Depending by the grid system you may have 50% to 100% chance of causing a short capable to destroy your instrumentation.
Also the trick that uses two probes directly may end up in catastrophic results if you work on voltages above 110V RMS.
In this video is presented a simple attenuator made of just 1/4W resistors, that guarantees safe operations with the oscilloscope provided the PE (Protective Earth, the yellow-green/green wire) is actually tied to ground. It still requires two input channels of your oscilloscope but it is safer than directly hooking the probes to the mains.

Full series of #Electronics:

[oscardominguez]

Great job, thank you for clarifying a very needed topic.

[lenslens]

For long time Im looking for this circuit
Thanks ❤

[walkerable]

My apologies I do follow after all! I think this is what I need to do in order to use Scope for TV repairs. Thank you

[zdenekspacek]

Thank you, i was always afraid to connect my scope to mains.I know what will happen, but I was nor sure way.

[BjornV]

If you just want to look at the 50 or 60Hz sine wave of your mains outlet with your scope, you don't need anything extra to build.
Mains outlet is referenced to ground / protective earth, your scope probe tip is also referenced to ground, so you don't need to connect your scope ground clip to the neutral of the mains. Just set your scope probe at X10, remove the groundclip and touch the Hot / Line / Phase of your mains outlet, and you will be fine without doing damage,
or tripping RCD. Also, if you have 2 x10 scope propes, you don't have to build any extra. Just set each probe at x10, connect both groundclips together, set your scope to measure differental by choosing channel B ADD to channel A, and set one channel reverted. You can then use one probe tip to touch Hot / Line / Phase and the other probe tip to neutral. Both groundclips are only connected to eachother, not to anything else.
Before i got a differential probe, i used method 1, by using 1 x10 probe and no ground clip. If you want to do measurings in circuits that are powered by mains, then method 1 is not advised. Grtz from Belgium

[walkerable]

struggling to follow but enjoyed what you did.

[walkerable]

Just wanted to say really enjoyed your presentation .I am in the UK so my mains plug has a fuse ie 3A will this be OK.Please advise.Lewis

[Chupacabras]

No capacitors for frequency compensation? I wander what's the bandwidth of this differential probe. I guess not huge.

[mahmoodmirza]

I wonder what to do in the situation faced by me?
The two Neutrals from the two outputs 230 VAC of the Nitrox Inverter ( 3 KW - 24 V, SP - Hybrid _ by A.P.T. ) aren't allowed to be jointed! At my home the PE and the Neutral are NOT jointed! Neither the Solar Panels nor the Inverter is Grounded till now! The Inverter demands the two Neutrals to be isolated and afloat! I'm rather perplexed. Obviously the two Phases are certainly to be distributed isolated!
The problem faced has been that either regular Load RCD or the Smart Load RCD have been in the habit of tripping off upon Grid On / Off since installation. Even sometimes the RCD on the Input to the Inverter also goes off!
The reason: the wiring of my home has become leaky for sometimes. I've been curious about the Phase difference of the two outputs of the Inverter. Is there any way to examine it's two lines 230 VAC (RMS) each. Probably phase difference of 120° with about 460 VAC (RMS) that amounts to be ~ 651 VAC RMS, oh no, sorry I mean to say 650 VAC Peak ! Moreover, the grounding croc clips of the O-Scope share the same common ground!
Is there any way to compare the 2 outputs, one 'Regular Load' and the other 'Smart Load' be visualized on single O-Scope screen with custom devised High Voltage Probe(s) X100 on single or Dual Channel OScope?
Note: The Inverter trips the RCD's on bringing the the neutrals near each other. I've a plan to examine the phase relationship of the Regular and the Smart Output phases without putting any load on these.
The OScope to be used is a Rechargable Battery Operated ( Floating ) DSO ’ZEEVEII DSO3D12’
I've seen your kind vlog on a ’DP’ Passive Differential Probe utilizing Dual Channels on an Oscilloscope for measuring High Voltage safely, safe for the Operator, the OScope and the Device Under Test DUT.
Would you suggest me to use similar probe for the situation faced by me.
I'm waiting for 2 Accessory DP4100
Probes X100.
With afloat DSO, the Cric Clips of the 2 DP4100 X100 grounded to earth and the probes on the two phases?
Wouldn't it be safe for me, the OScope and the electrical system?
Awaiting your kind response!

[walkerable]

Me again! would you be prepared to construct this circuit on a Copper board in order to purchase from you? Just a thought. I saw you in another video doing another circuit construction. Thank you

[mahmoodmirza]

9:42
I suppose at this point you meant 230uA rather than 320uA? O.K.?
What are the safely full scale voltage measured by O-Scope with X1 and X10? Are these 3.2 and 32 VDC or RMS?
990 KOhm is almost 1000 KOhm or 100 MOhm to constitute a Probe 100X while in unison with standard 10X one.
In my humble opinion, wouldn't have it been better if the Standard Probe used in X1 confuguaration for safety of the O-Scope?
And all calculation done on the later basis?
Help me if I'm confused.
I'm a medical doctor happened to be an accidental scientist: may be on wrong side!
I've never used any O-scope other than patient bedside monitors. My first ever entry level Chinese Rechargable, Dual Ch, SigGen O-Scope+DMM (ZEEVEII-3D12) with Voice-Assistant reached me 2-3 days ago. In search of safe use of the same I touched your Youtube channel.
In my life, I've been moved by a few, and you are one among those, I happily ❤️ declare.
Help me please if I'm confused or wrong!
Thank you.

[mahmoodmirza]

Mains operated O-Scopes are grounded by the mandatory earth wire to guard off againts the radio waves, electromagnetic interference from nearby equipment or internal echos from O-Scope itself! Ain't I right?

[jonm]

What about battery operated oscilloscope?

[alxvlx]

Когда будет продолжение с постройкой токарного станка?

[TheGreatAtario]

Joke's on you, my place's wiring is old and all the retrofitted grounded power sockets just leave the ground floating (-_-)

[Jumansa]

Wow !
Very good explanation and nice drawings.
Like thus your presentation style ("if you like a dangerous live", "this is not ElectroBOOM", ...) and that you definitely know what you are talking about.
It would be interesting to know something about your professional and educational background, because what you are presenting is certainly not from the hobby "maker" scene, but indicates profound knowledge and a lot of experience.
Where are you from? Where u get your education - i guess somewhere from an ex "communist" country?
Also, i like that you don't show only an oversized expensive "buy and use" (at "your" affiliate link - to sponsor your youtube hobby...) ready product, instead you show a good cheap and long proofed, safety(enough - if "you" have to die it will happen also crashing airplane could hit you...) solution.
Thumbs up, quite a lot of "cool professional electrical engineering" (oh well...)channel self-promoter could learn a lot of from your knowing and even more how you present your self to be modest and how to take the audience seriously (not this "hello brother" " hello folks" stupid semi friendly for just want to sell something and looking for clicks...)

[Uvisir]

so basically make a differential probe instead of buying one hehe

[tubosolinas]

For simplicity we will use a single phase oscilloscope! 🤣 Great video btw!