Hello Engineer Bob, first of all I am an electronic technician (associate degree) means technical school. All I know to use is analog and digital multimeter in simple way. Even though I am 50 years old I still continue to be a technician. After all, I was dreaming of how to learn to use an oscillocope but back then the oscilloscope was expensive so I didn’t have one. And as I continued to watch youtube about using a digital oscilloscope I became interested again and you and your video tutorials enlightened me mentally. You are good at teaching. You speak in English in a simple way and understandable. I can't get out of my mind what you say "oh don't forget mr trigger, mr cursor and so on", I'm glad I've learned something. I know it’s not enough I know but it’s just the beginning of the first step to learning. I want to learn how to use an oscilloscope, how to troubleshoot to know where the faulty erea is. I'm confused with those that capture the signal in oscilloscope, I don't know where the signal is or therefore how to capture the signal (is it audio or video signal). I hope you can help me Mr. Engineer Bob. I hope you have more video tutorials on how to use and how to use the oscilloscope when it comes to circuit boards. If you don't mind, hope I can find out your fb account so that I can share more of your teaching skills with others. Thank you very much. From the Philippines.
I'm an amateur ( basically a medical doctor since 1986 ) and happened to be an accidental scientist. I'm totally new to Oscilloscopes. Though DMMs have been in my use for many years yet I never touched any OScope. I got my 1st ever DSO a week ago, and started studying safe use of an Oscilloscope. Only having gone through Vlog I came to know how essential a Differential ( may be Passive or Active ) probe is for safety of the Operator, OScope and also the circuit board under examination! Thank you very much , sir! I've been following some great channels before like Keysight and Accidental Science. Today's lesson: Using Regular OScope Probes, always put the Crocodile Clip to Chassis Ground and the other ( pointed ) probe to any where else. Use only Differential Probes set ( DP xxxx ) a HOT Stage!
You are one of the best in explaining how to operate the right way with the oscilloscope. Many swear to isolate their scopes with certain transformers, but i see there is no 100% safety. I knew that the protection earth is very, very important. I see the main key in this video on the part with the differential probes. People with no experience operating with AC and high voltage destroy their scopes without the proper use of additional equipment and precautions. Personally, i never used the scope for measuring of high voltages. I was to concerned to destroy it. I have also no differential probes. But if you work on a development or modding project, where you want to see how the filtering and other signals work, then a purchase of such probes is a must. Keep up the nice and informative videos. Have a nice day my friend.
Amazing video! Thanks! I guess the principle of the differential probe also apply when working with chips connected to Usb on a computer running on main line (not on battery) - this is the best video on the topic. Thanks!
Trouble is that a proper diff MICSIG probe costs $300-400 nearly as much as my precious DSO - so yours was a sponsored informercial. So using two probes (connect the crocs together) and using ch1-ch2 math function (on modern DSO) is a simple way and built in. Another simple way is to use a small 1:1 audio xformer (5$) and use the primary as probes and connect the secondary to the scope
Thanks for the video - this is a super important topic and actually well explained. Just to be honest, some parts I really had problems to understand your English and therefore I still have some confusions ... The GND in the 'cold area': As you have shown properly, the (cold) GND is only connected with a coupling capacitor. And this is what I don't understand: In my case I am currently having an expensive circuit of a complex air to water heat pump system. When I measure the (cold) GND to the DCN ground, which is the "hot ground" after the rectifier - by using a multimeter - I'm having a difference in voltage! So I can not connect the oscilloscope - even to that cold GND - or at least I don't dare to try it! I'm fully aware that I need a differential probe to be save. But STILL I would like to understand: How can I better understand the cold GND and the coupling capacitor? Would it even be save to connect the probe on the cold ground - even I measure a voltage difference ... maybe because it is 'only' voltage potential with no energy (maybe because of the coupling C)? PLEASE HELP ME UNDERSTAND THIS 🙏 Thank you so much! Greetings
Practically nothing - as long as you don't open the case of your oscilloscope. In both cases the PE line is disconnected from the chassis. But with only the chassis disconnected, make absolutely sure not to touch any part of the scope's internal power supply if you open it - but why would you want to open it in the first place? However, I advise you not to disconnect the chassis completely, use a resistor of 5.6k (110V mains) to 12k (22V mains) to connect it to PE instead, even with an isolation transformer. These values can be even smaller. The function of the resistor is to limit the current that may flow through the probe and your scope if you accidentally make a bad connection. The resistor should have a corresponding wattage to survive the possible max. current of 20mA. 20mA won't blow your scope or the test probe but will in most cases protect the scope from electrostatic discharge. A more expensive solution may be the use of a multi-layer varistor between the chassis and the PE line. This provides complete isolation but protects from electrostatic discharge. CAVEAT! I'm a hobbyist, not an expert. Please consult an expert before applying my advice.
If I discounted the PE, is it possible for a normal HBM electrostatic discharge to blow my 1k$ oscilloscope?? Even a 15$ bug has a protection for a such scenario! Am I right, or do I get it wrong?
@Bob. Much as I appreciate aspects of this video, namely measuring the chasis to earth voltage, all it did was make people worried about using their oscilloscope and possibly try to get them to buy a probe. You did not include your circuit either. . My oscilloscope sat in a cupboard for a year due to concerns. The best videos are EEVBlog th-cam.com/video/xaELqAo4kkQ/w-d-xo.html (how not to blow up your oscilloscope). Howto make differential probe th-cam.com/video/zQDLY-ot4eo/w-d-xo.html&t=11s th-cam.com/video/-hP30AQCrqk/w-d-xo.html How to measure mains th-cam.com/video/a3ePild_sFs/w-d-xo.html
Someone should explain to me then. If a battery powered oscilloscope is "protected" against electrostatic discharges. Why dont they do it to normals ones too? Well I understand, there is no battery ground or whatever. But shouldnt that be possible. So have line powered oscilloscopes that can float and be protected from electrostatic dischagres too? And then I checked on how much differential probes cost. Even the cheap ones. It makes more sense to buy a cheap battery powered oscilloscope (even one with just 50Mhz) than a differential probe... Because working on the hot part. You actually never see frequencies higher than a few hundred Khz. And then have an extra small and mobile oscilloscope.
![[MV] A leap of faith...ความเชื่อใจครั้งสุดท้าย (From "Petrichor the series")](http://i.ytimg.com/vi/U1piZH2CNXA/mqdefault.jpg)
Hello Engineer Bob, first of all I am an electronic technician (associate degree) means technical school. All I know to use is analog and digital multimeter in simple way. Even though I am 50 years old I still continue to be a technician. After all, I was dreaming of how to learn to use an oscillocope but back then the oscilloscope was expensive so I didn’t have one. And as I continued to watch youtube about using a digital oscilloscope I became interested again and you and your video tutorials enlightened me mentally. You are good at teaching. You speak in English in a simple way and understandable. I can't get out of my mind what you say "oh don't forget mr trigger, mr cursor and so on", I'm glad I've learned something. I know it’s not enough I know but it’s just the beginning of the first step to learning. I want to learn how to use an oscilloscope, how to troubleshoot to know where the faulty erea is. I'm confused with those that capture the signal in oscilloscope, I don't know where the signal is or therefore how to capture the signal (is it audio or video signal). I hope you can help me Mr. Engineer Bob. I hope you have more video tutorials on how to use and how to use the oscilloscope when it comes to circuit boards. If you don't mind, hope I can find out your fb account so that I can share more of your teaching skills with others. Thank you very much. From the Philippines.
I'm an amateur ( basically a medical doctor since 1986 ) and happened to be an accidental scientist. I'm totally new to Oscilloscopes. Though DMMs have been in my use for many years yet I never touched any OScope.
I got my 1st ever DSO a week ago, and started studying safe use of an Oscilloscope. Only having gone through Vlog I came to know how essential a Differential ( may be Passive or Active ) probe is for safety of the Operator, OScope and also the circuit board under examination! Thank you very much , sir!
I've been following some great channels before like Keysight and Accidental Science.
Today's lesson:
Using Regular OScope Probes, always put the Crocodile Clip to Chassis Ground and the other ( pointed ) probe to any where else.
Use only Differential Probes set ( DP xxxx ) a HOT Stage!
From Canada ,this is probably the best explanation for a proper connection for oscilloscope. Muchas Gracias. Mike from Canada
You are one of the best in explaining how to operate the right way with the oscilloscope. Many swear to isolate their scopes with certain transformers, but i see there is no 100% safety. I knew that the protection earth is very, very important. I see the main key in this video on the part with the differential probes. People with no experience operating with AC and high voltage destroy their scopes without the proper use of additional equipment and precautions. Personally, i never used the scope for measuring of high voltages. I was to concerned to destroy it. I have also no differential probes. But if you work on a development or modding project, where you want to see how the filtering and other signals work, then a purchase of such probes is a must. Keep up the nice and informative videos. Have a nice day my friend.
This is the only video I have found that has given the exact information I've been looking for. Thank you so much for this!
this is the best clarification on youtube on how not to blow up your scope
thank you
This is a good video explaining the safety of using test equipment and how differential probes are so necessary .
The best man ever in electronics TH-cam
Exactly was I was looking for, super clear, direct to the point. Thank you for the great explanation.
I appreciate your work and sharing VERY IMPORTANT information. Thank you!
wow THANK YOU Your are the only one Who teach the right way on youtube wow
Can you please share your DIY differential probe? It will be an interesting video.
Also a good case for safety...
wow !!!!! Crazy good video of a real true scientist, Thx a lot
Yes indeed, very informative video! Thankyou!
An absolute master and a beautiful human being!
Best explanation I could find till now... Thank you
Very good information. Thanks for the video!
Amazing video! Thanks! I guess the principle of the differential probe also apply when working with chips connected to Usb on a computer running on main line (not on battery) - this is the best video on the topic. Thanks!
Excelent saw many videos that I did not understood now I do thank you! Now anothe video would be DIY diferential probes! :)
Trouble is that a proper diff MICSIG probe costs $300-400 nearly as much as my precious DSO - so yours was a sponsored informercial. So using two probes (connect the crocs together) and using ch1-ch2 math function (on modern DSO) is a simple way and built in. Another simple way is to use a small 1:1 audio xformer (5$) and use the primary as probes and connect the secondary to the scope
¡Thank you so so much for making and posting this video! May the Lord[Bible] bless you to overflowing.
Amazing video Sir. Thank you for taking the time to do it. 👍
Thanks Bob for the knowledge. Can you please shows us the poor man differential probe?
Thanks for the video - this is a super important topic and actually well explained.
Just to be honest, some parts I really had problems to understand your English and therefore I still have some confusions ...
The GND in the 'cold area':
As you have shown properly, the (cold) GND is only connected with a coupling capacitor.
And this is what I don't understand:
In my case I am currently having an expensive circuit of a complex air to water heat pump system.
When I measure the (cold) GND to the DCN ground, which is the "hot ground" after the rectifier - by using a multimeter - I'm having a difference in voltage!
So I can not connect the oscilloscope - even to that cold GND - or at least I don't dare to try it!
I'm fully aware that I need a differential probe to be save. But STILL I would like to understand:
How can I better understand the cold GND and the coupling capacitor?
Would it even be save to connect the probe on the cold ground - even I measure a voltage difference ... maybe because it is 'only' voltage potential with no energy (maybe because of the coupling C)?
PLEASE HELP ME UNDERSTAND THIS 🙏
Thank you so much!
Greetings
Thank you so much for advise. Very clear and easy to understand.
Excelente video. Si lo publicara tambien en español por favor. Gracias
Excelente Video.... Please en Español... Saludos.
The alligator goes to chasis only in mothern gear. Tube gear may have hot chasis (the chasis may be conected to full line voltage).
Hai what about use an isolation transformer plus a differential probe , that makes more safe....... please explain......
Thales you from Brazil
I was a bit confused by the use of the transformer symbol for a variac - which only has a single winding. Is this the correct symbol?
Me interesa mucho lo podria hacer por favor en español para saber de que manera puedo proteger mi osciloscopio gracias
What is the difference betweem removing the chassis and isolation transformer?
Practically nothing - as long as you don't open the case of your oscilloscope. In both cases the PE line is disconnected from the chassis. But with only the chassis disconnected, make absolutely sure not to touch any part of the scope's internal power supply if you open it - but why would you want to open it in the first place?
However, I advise you not to disconnect the chassis completely, use a resistor of 5.6k (110V mains) to 12k (22V mains) to connect it to PE instead, even with an isolation transformer. These values can be even smaller. The function of the resistor is to limit the current that may flow through the probe and your scope if you accidentally make a bad connection. The resistor should have a corresponding wattage to survive the possible max. current of 20mA. 20mA won't blow your scope or the test probe but will in most cases protect the scope from electrostatic discharge.
A more expensive solution may be the use of a multi-layer varistor between the chassis and the PE line. This provides complete isolation but protects from electrostatic discharge.
CAVEAT!
I'm a hobbyist, not an expert. Please consult an expert before applying my advice.
Thanks for advice i'll be try it
good video and explanation
This some good information, thanks man!!!
Thank you. A very good video.
very good video
If I discounted the PE, is it possible for a normal HBM electrostatic discharge to blow my 1k$ oscilloscope??
Even a 15$ bug has a protection for a such scenario!
Am I right, or do I get it wrong?
Thank you 🙏🏼
Excelente tema porfa en español.
“Hot” = Primary, “Cold” = Secondary
@Bob. Much as I appreciate aspects of this video, namely measuring the chasis to earth voltage, all it did was make people worried about using their oscilloscope and possibly try to get them to buy a probe. You did not include your circuit either. . My oscilloscope sat in a cupboard for a year due to concerns.
The best videos are EEVBlog th-cam.com/video/xaELqAo4kkQ/w-d-xo.html (how not to blow up your oscilloscope). Howto make differential probe th-cam.com/video/zQDLY-ot4eo/w-d-xo.html&t=11s th-cam.com/video/-hP30AQCrqk/w-d-xo.html
How to measure mains th-cam.com/video/a3ePild_sFs/w-d-xo.html
At 2:05, that is not 8mv. 8 tenth of a mv. 8 mv = .008 with just two zeros. The screen is showing .0008 volts.
0.0008 V are 800 μV or 0.8 mV not 8 mV. Multimeter show V letter on down right corner.
Someone should explain to me then. If a battery powered oscilloscope is "protected" against electrostatic discharges. Why dont they do it to normals ones too? Well I understand, there is no battery ground or whatever. But shouldnt that be possible. So have line powered oscilloscopes that can float and be protected from electrostatic dischagres too?
And then I checked on how much differential probes cost. Even the cheap ones. It makes more sense to buy a cheap battery powered oscilloscope (even one with just 50Mhz) than a differential probe... Because working on the hot part. You actually never see frequencies higher than a few hundred Khz. And then have an extra small and mobile oscilloscope.
It is hard to understand the danger of how the oscilloscope blows. Things are not clear. Sorry, l’m having a hard time getting the PE and GND.
Sorry but I do not understand you.