{662} Oscilloscope - Safeties While Using DSO, CRO, Waveform Recorder

[@olaleyejoshua949]

Dear Haseeb. Great videos from you are well appreciated. You generous efforts are impacting positively on your generation and beyond. I am a regular fan of your educative videos. I am in Nigeria. Thanks.

[@corneliodaquil8414]

sir i am in the philippines watching your youtube channel i appreciate you,you explain will how to test and use the oscilloscope in the right way without damaging i have an oscilloscope but i didnot use yet , thank you God bless.

[@niknam.]

Best explanation of this problem ever i saw! Thank you!!!

[@Radek__]

Thank you so much for that detailed explanations. I finally understand why I have to be careful. Greetings from Poland.

[@windward2818]

For Isolated Adjustable AC power sources on the bench you will generally find two types. Those dedicated to final test and calibration and those used for troubleshooting field returns. Isolation will be from the DUT side and not by ungrounding (unearthing) the scope. If you have a return or a repair, you will always start testing with the Isolated Adjustable AC troubleshooting power supply. The heart of this AC supply is a 1:1 isolation transformer usually followed by a Variac. The Variac provides a way to adjust the AC source voltage level, however you cannot change the line frequency, which is why you will see, depending on where you live, versions with a base frequency for 60Hz or 50Hz. Also, noteworthy is this type of AC source will obviously have the mains isolated, but in addition, will have the earth ground isolated using a ground isolated receptacle. Meaning the AC Troubleshooting supply case chassis will be grounded (earthed) but not the device under test by the receptacle ground pin, its ground from the AC supply front panel plug is floating. This feature is only really possible if you use an isolated ground receptacle (which you can buy), which is a special design which floats the ground relative to its metal mounting screws. Also, it is assumed you are not floating your scope. The other type of variable AC power supply is for final test and calibration after you have repaired the equipment with the previously mentioned troubleshooting AC supply. The out going test supply allows you to vary the AC voltage and the AC line frequency. However, the chassis ground (which is earthed) is not isolated from the front panel test receptacle. Which means the earth ground is not floating. This is okay because normally you will not be using an oscilloscope to set any final voltage output level calibration, you will be using a high accuracy bench DMM which is floating in regards to earth. Even though you use the appropriate AC source for what you are doing, you must remember when using an oscilloscope that does not have a floating front end, that all the probe grounds are connected together, and connected to the chassis and is normally earthed. So, when testing you can only reference one point in the circuit which is ground when using an isolated supply. You can float the scope if needed, but remember not to touch the ground clips or BNC housing because they are all cross connected. If you watch Hasseb's channel you will notice he does a lot of repair work with his home brew version of an isolated repair power supply. This is common place for many technicians who like to build their own AC isolated power supply for repair, it just depends on what you are repairing and what features you feel are best suited for the job. I also do a lot of troubleshooting like Haseeb Electronics although I use a Fluke Scopemeter which is well suited to repair because it has fully floating inputs both from ground (it is battery operated) and from each other, so you can take voltages across different components even though they do not share a ground. My Scopemeter has a bandwidth of 200MHz and has many automated measurement features. It is well suited for industrial troubleshooting. Even though you may have an isolated oscilloscope you should always use an isolated AC power supply. There are many advantages to using a bench AC isolated adjustable power supply. One is if you provide meters to read output current and output voltage, you can set the voltage to a known value before turning on the supply. You can also observe the current draw as you turn on the DUT, because many times the failure mode will exhibit a certain type of current draw behavior. This is especially true if you work on the same model of equipment, or family of equipment. This is because many times the failure modes will repeat on equipment of about the same age, and once you understand the current signature, you can diagnose the DUT just by watching the current. There are many other features you can add like multiple ranges each having its own circuit breaker protection.

[@captaintube2696]

@Haseeb Electronics - At 12:45 you explained that when we connect the LO of the Oscilloscope to the LO of the power supply, it would be a problem. You also said that the 220v of Line would go through the reverse biased diode to reach the LO of the scope. Can you please clarify why 220v would pass through a reverse biased diode ? I would have assumed that the issue is when we connect the LO of the scope to the HI of the power supply.

[@matsu9790]

He did not answered because he made mistake - it happend all of us.

[@HaseebElectronics]

No dear I try my best to reply to comments But sometimes I miss comments due to the busy time, Now I saw the comment, and I noted it in my schedule I will explain it and do it practically.

[@HaseebElectronics]

@matsu9790 I will prepare a detailed explanation and practical of my content in this video I will try my best to share it as soon as possible

[@repairlab14]

Useful video, like! ) I am using differential probe and a grounded digital oscilloscope. Early I am using an analog oscilloscope with transformer. It was worked not correct on full-bridge inverter.

[@HaseebElectronics]

exactly that is awesome configuration differential probe is superb, and grounding the scope, that is superb analog scope with transformer, (without grounding) works good, but it is very dangerous, because most of analog scopes have metallic chassis, which are directly coupled to line voltage while testing unislated signals.

[@NMS1122]

Shukriya, very important information... Same Scope Mai bhi use kar raha hu. Meri aap se request hai ki SMPS testing ke samay Scope ke parameters kaise aur konse set karne se properly signals measure kar payenge. Ye information bohot badiya hai 👍👍👍👍👍

[@ElectroWorkshop-]

very helpful. if you could demonstrate on a live circuit for one of your upcoming videos that would be useful. dc and ac circuit with pwm signals eg. inveters and dc-dc

[@temyraverdana6421]

You are right, without follow your tips the misure is very dangerous to made. Thanks for your important lesson

[@HaseebElectronics]

best regards

[@manojrankawat4201]

Very knowledgeable full video Thanks alot..👍👍👍👍

[@HaseebElectronics]

it is my pleasure

[@clems6989]

Thank you again. I made this mistake yesterday. With SMPS and Tektronix 2225 scope. Blew the fuse and blew the NTC apart. Didnt damage my old scope though, shes a tough of bird...lol Question: i have always been told to isolate the DUT. Never the test equipment. Why? Thanks again my friend!

[@HaseebElectronics]

Oh, that is so sad. but it is life, and in life we learn from experiments best practice to Isolate the DUT, but it needs some high wattage transformer (in KW) and without ground in that case we can use grounded Test equipment but if we don't have high wattage transformer to isolate DUT, then it is best to isolate TMDE, so it becomes the easiest solution or just remove the grounding pin from the power plug of oscilloscope otherwise the live voltage are directly grounded to earthing point and causes damage to DUT or TMDE

[@clems6989]

@@HaseebElectronics Thank you do much my friend, your videos are the best..

[@lifeofapillion8006]

Thanks for the Informative Video. I have dout, why Auto transformer is not recommended to use for Isolation (as you explained in this video. Please clarify my dout.

[@HaseebElectronics]

best regards auto transformer just steps down using center tapped winding. so it never provides isolation. so there is no benefit while using autotransformer

[@lifeofapillion8006]

@@HaseebElectronicsgot it. thank you.

[@muhammadishtiaq24]

Excellent explain thanks for sharing this informative video

[@razakhrazakh3427]

Sir I have purchased dso own hds2102s its self battery powered pls sir describe about on safety feauters of dso which is self powerd

[@thisoldjeepcj5]

I have tripped the breaker but did not damage probe, scope or circuit under test. I know of what you speak! However, cutting the ground pin off will get you a failed inspection and likely a lot of argument from others.

[@el_sturlo]

Hi, thanks for the video, i have a question, some people put the device under test on the output of the isolation transformer and then they connect the oscilloscope with earth under the normal socket (not under isolation). Is it safe ? Thank you

[@HaseebElectronics]

Yes, exactly the same i explained it in the video we can use isolation transformer to power up UUT (unit under test) without ground then we can use 3 wire powered oscilloscope (line, neutral & earthing) from the wall socket directly. we can test the circuit. basically we provide isolation to any unisolated circuit, by means of isolation transformer to apply power to uut

[@ziadfawzi]

Thank you Mr. Haseeb.

[@maheshmishra5235]

Thank you sir for your valuable information. God bless

[@HaseebElectronics]

You are most welcome

[@JagdishAdusumalli]

Hi hasseb sir, i was watching a video of putting a LED indicator on to a AC electric switch and the channel "Dharmendra Experiment" uses a 22k 0.25w resistor with diode to make it..there are people in comments questioning on why 220k resistor and how he arrived at that value..i would like you to let us all know is this a right thing to do? and will it work consistently? and if yes what are the right component values to use and how those values are determined..Video Title is How to make 220v AC Led indicator light | 220v AC to 3v LED Light

[@dhanuskalankathilaka]

Great explain 💯👍

[@HaseebElectronics]

it is my pleasure

[@rul1175]

I love your videos. I have learn alot from you.

[@faizalkattoo7283]

Thans you sir l got it good information becouse i am planig to buy a dso 👍🏻👍🏻👍🏻👍🏻

[@HaseebElectronics]

best wishes dear brother

[@bmsfx]

But you can also just inject voltage on the output line eg. 12vdc if its a 12v dc transformer, and measure atleast the secondary side right? Just got my oscilloscope , been like a million years since last use one :P

[@huongtoituonglai24]

MA SHA ALLAH .wow such a beautiful view🌾🌾

[@HaseebElectronics]

best regards

[@shefqetkaralliu6816]

Piacere a seguirti maestro. 🙏👍

[@HaseebElectronics]

it is my pleasure

[@mohamedrasheed201]

Please how can I measure primary smps pulses please

[@sreekanth369]

Sir Namate Very Good Video Sir.. Kind of You..

[@HaseebElectronics]

Thanks and welcome

[@fazrisedan4182]

What if we use isolation transformer on both sides, the DUT and the oscilloscope, is this safer?

[@shawkifekri5081]

Great video thanks alot my brother 🙏

[@HaseebElectronics]

best regards

[@ahmedmadkour]

Great job give you big 👍 keep safe

[@HaseebElectronics]

Big thanks

[@rul1175]

What would happen if the alligator(ground) touches the probe???? Would the oscilloscope stop the power? Or do the probes dont have current like multimeter?

[@delwarhossain9648]

Sir,I have a question - in ac voltage why do we get shocked when we touch phase line but not neutral though ac voltage change it's direction 50 or 60 times in second.

[@HaseebElectronics]

because ground or earth is approximately potential as neutral. that is reason we don't get shock. but voltage measured between live line wire and neutral are high voltage, that is reason for electrical shock i will suggest to watch video umber 414 for a detailed answer.

[@boriscache6350]

Hi Sir and thanks a lot for your videos that I expect every day. Could you make one about the use of the oscilloscope while repairing something?

[@electroniquepassion]

Salut, la meilleure sécurité c’est la sonde différentielle 👍👋

[@HaseebElectronics]

oui frère, la sonde différentielle est très utile. c'est cher aussi

[@electroniquepassion]

@@HaseebElectronics Oui c’est vrai et c’est pour cela que je possède un transformateur d’isolement. 👍 j’aime bien tes vidéos car elles sont très instructives. 👋

[@HaseebElectronics]

@@electroniquepassion meilleures salutations et remerciements particuliers cher frère. c'est ta grandeur

[@susantaatha6468]

Excellent. Thank you sir.

[@HaseebElectronics]

Most welcome!

[@apmtalk.s]

I am planning to make an isolation transformer for my work bench is it good 220 volt primary and secondary with 500 Watt is it good to connect my ocilloscope with 500 watt transformer

[@HaseebElectronics]

yes it is enough for oscilloscope

[@garn6223]

Thank you very much sir 🙏 🙏🙏

[@HaseebElectronics]

best regards

[@mohamedrasheed201]

Please P2301C oscilloscope probe 300MHZ 5000v can measure smps primary voltage

[@yanalali7660]

Thanks for sharing Sir hamid ali

[@HaseebElectronics]

So nice of you

[@gregorybolin4672]

Liked please explain in video grid tie inverter circuit no hobbyist can make such a circuit thanks.

[@lupojacobo9892]

Shukriya Maestro

[@HaseebElectronics]

most welcome

[@sudheerkumar5966]

Very very good 👍

[@HaseebElectronics]

Thank you very much

[@hasanrahman4100]

If you remove earthing from oscilloscope any problem for any fault?

[@Versatiledani]

Nice sharing

[@mohamedrasheed201]

Thank you very useful video

[@HaseebElectronics]

it is my pleasure

[@mohamedrasheed201]

Please P2301C oscilloscope probe 300MHZ 5000v can measure smps primary voltage

[@maksroma]

What happens if I power the oscilloscope from the charging station? As I know, it generates 220V from the inverter, but the main power to the inverter comes from the battery. Will it be safe?

[@philipscharles1333]

this video is very useful to me sir thank you so much sir please explain about signal generator sir.

[@nelsoncarmengomez7416]

Los últimos serán los primeros- hahaha un abrazo, amigo.

[@HaseebElectronics]

jajajajaja, como en los videos siempre se muestra la solucion numero 1 al final. mientras que la calidad más baja comienza desde el número 10, luego 9 y baja a 1, pero yo empecé desde 1 y luego hacia abajo. pero realmente, la última solución también es aceptable

[@neoris7833]

I am using only usb or powerbnk for oscilloscope for safety

[@HaseebElectronics]

that is a perfect solution

[@mohdasim1028]

Ic cm6805A working detail please 🥺🥺🥺🥺🥺🥺🥺🥺🥺

[@philipscharles1333]

sir what is the maximum voltage we can measure in oscilloscopes sir

[@dantronics1682]

if using a x10 probe in theory you can measure 1kv but I wouldnt go above 600v due to component spacing

[@joeshmoe7899]

GFI?

[@AbdulMomenZargar60]

Subha Bakher Ho Bhai Saab

[@pu8reLib]

v good sir

[@HaseebElectronics]

most welcome

[@aanish2.094]

Aslmuailkum with lk dn

[@HaseebElectronics]

thanks a lot dear sister

[@joeshmoe7899]

Use 2 probes, detaching ground clips? Use math function to subtract.

[@HaseebElectronics]

Yes, you are right

[@roseelectronics4582]

Sir is you scope sufficient to test any SMPS?

[@HaseebElectronics]

yes dear it is enough for routine work but if we select 600V or 1000V range, that are much safer but that are toooooo expensive as well