Author Topic: With a budget of $400 - Rigol or Siglent scope?  (Read 16591 times)

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Offline rsjsouza

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #75 on: February 04, 2018, 03:01:09 am »
I guess I see the OP's point: when we are exposing kids to a new thing, it is important to show the two sides of the coin. Ideally this should be done in a controlled environment with all the appropriate warnings and no possibility of collateral damage, but that is impossible due to uncontrollable factors: liability, parents' reaction, equipment failure and that 0.01% chance that someone will have further health issues or death.

We certainly came from a different world, where we really experienced jolts, saw pliers or screwdrivers give up the holy ghost and rules and "responsible party" interference was much less present - we survived even after these zaps and jolts, but what about the ones who didn't? Statistics are cold and distant until it happens with someone close to you and that is why the overreaction/control exists today (some excessive, but still). 
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Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #76 on: February 04, 2018, 03:39:30 am »
You guys are brittle.  Hope do you expect studnets to learn if they don’t experience life?  Did I ever say I was intentionally zapping kids?  NO!  I leave that the the Physics instructor who has a Van de Graaff generator?  Did I even say I would intentionally let any of these studnets get hurt?  Nope. I leave that up to the PE coaches.  Yes parents trust their children to our schools and expect them to be educated and not injured.  I agree - But then why are we teaching PE?  I don’t think a day goes by when there isn’t a studnet who is being injured and some of the injuries they receive are debilitating taking months to heal.

No one has been able to tell me of one instance where a student in an electronic class was killed or even had a long debiilating injury.  Worst thing that happens in electronic class is the kid receives a mild momentary shock.  And in some classes like physics they make devices (step up transformer) to shock one another .

Are you folks trying to tell me you have never been zapped?   Did it kill you?  Are you maimend for life.  Or did you learn somehting after getting zapped?  I suppose after getting zapped you decided not to pursue a career in electronics.

You do realize even with digital 3 and 5 volt circuits students can still get zapped.

Folks we need to get this studnets trained for the real world.  I had an professor in college who would call the campus electrician to change the batteries in a flashlight.  Why asked why he didn’t do it himself he said batteries are filled with electricity and electricity is dangerous. I don’t what to get hurt.

This is what happens when to try to over protect our children from leaning.   

 

Offline CharlieEcho

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #77 on: February 04, 2018, 04:18:21 am »
Are you folks trying to tell me you have never been zapped?   Did it kill you?  Are you maimend for life.  Or did you learn somehting after getting zapped?  I suppose after getting zapped you decided not to pursue a career in electronics.

You do realize even with digital 3 and 5 volt circuits students can still get zapped.


"Zapped" is not a binary condition. That's why most of us are still here. Getting "zapped" with 5VDC is not like getting "zapped" with 120VAC -- I've experiened both and I'd rather not experience the latter ever again. I got lucky. And wouldn't you know it, it happened when I was a dumb 13 year old kid.

It's entirely likely that everything would go fine. And from a probabilistic perspective, yeah, your students will likely not go stick a free Harbor Freight meter into the outlet at their next family gathering. But,  improbable is not impossible. Your students didn't learn this stuff in the age of vacuum tubes. Indeed, they haven't learnt it at all, you're introducing it to them and it behooves you and your school to do so with a great deal of caution and an emphasis on safety.

When's the last time your students paid perfect attention to any of your lessons and came away with a 100% understanding? Treat youth like youth. Beginners are beginners. Take risks on your own time.

Also, if you don't think you're going to be in the shit career-wise if one of your students gets shocked messing with the mains -- in or out of the classroom, and regardless of whether it kills them -- then you've got your head somewhere south of the books. And north of the ground.
 
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Offline Someone

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #78 on: February 04, 2018, 05:03:11 am »
No one has been able to tell me of one instance where a student in an electronic class was killed or even had a long debiilating injury.  Worst thing that happens in electronic class is the kid receives a mild momentary shock.  And in some classes like physics they make devices (step up transformer) to shock one another.
You could also find it impossible to show that no student has ever died in an electronic/electrical classroom, record keeping is very inconsistent and hard to access so the deaths that have occurred are very hard to extract with such specificity. Then electronic/electrical classes are so rare that its hunting for a rare event in a tiny population and there may well have been no occurrences but that doesn't mean ignoring basic safety requirements is the right thing to do.

Electrocutions have and do occur in schools in the US:
http://www.thespectrum.com/story/news/local/2017/03/29/schs-student-severely-burns-himself-school-equipment/99787512/
http://www.delcotimes.com/article/DC/20100925/NEWS/309259991
https://www.cpsc.gov/s3fs-public/Electrocution-Report-2004-to-2013.pdf?V_9Zl10pv4Wz03uBPRx78IctKRABjYDv

But its teachers such as yourself lacking the most basic understandings of the material needed to teach it safely that is causing the ever increasing red tape and requirements upon which teachers need to attain before they can teach specialist topics (I know of people who're retired rather than going through the modern reassessments to be qualified to continue teaching what they've been doing safely for a lifetime). From what you've posed and the dismissive attitude to safety you're the worst of the worst, perhaps you'd like to confirm your current position and faculty?

110V is still able to deliver very dangerous fault conditions:

And you can't simply rely on breakers to solve all the problems:

Safety requires multiple layers of protection, single point failures should not leave a student in danger so even a circuit with a RCD/AFCI/GFCI (or combination there of) is still not enough to ensure safety.

Hope [sic] do you expect studnets to learn if they don’t experience life?
They should be learning in well planned courses with teachers/instructors who understand the material and can teach it safely. These experiences can be taught to students but not safely by you.

This is what happens when to try to over protect our children from leaning.
No, this is what happens when there are charlatans posing as concerned teachers.
 
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Offline Someone

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #79 on: February 04, 2018, 05:15:21 am »
When's the last time your students paid perfect attention to any of your lessons and came away with a 100% understanding? Treat youth like youth. Beginners are beginners. Take risks on your own time.
Even with explicit step by step instructions noted as essential for safety some students will ignore it anyway, and then complain if you try and eject them for being dangerous....   When there is safety involved it really requires one on one supervision.

Also, if you don't think you're going to be in the shit career-wise if one of your students gets shocked messing with the mains -- in or out of the classroom, and regardless of whether it kills them -- then you've got your head somewhere south of the books. And north of the ground.
I wouldn't let students anywhere near live mains, if they were doing some work with mains then it would be inspected before energizing and that would be inside an appropriate grounded/armoured/interlocked enclosure as appropriate. Teaching mains technology/coursework is often done with either low voltage analogs (24V AC etc) or completely insulated to the standards of consumer equipment so that there is no possibility of exposed shock hazards, as above voltages can be measured on appropriate step down transformers integrated into the benches or equipment, and currents by non contact methods all routinely hi-pot tested for breakdown/damage of the insulation. As much as some people dislike the shrouded banana plugs they sure made it easier to let students connect mains voltages.
« Last Edit: February 04, 2018, 05:17:16 am by Someone »
 

Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #80 on: February 04, 2018, 05:35:29 am »
No one has been able to tell me of one instance where a student in an electronic class was killed or even had a long debiilating injury.  Worst thing that happens in electronic class is the kid receives a mild momentary shock.  And in some classes like physics they make devices (step up transformer) to shock one another.
You could also find it impossible to show that no student has ever died in an electronic/electrical classroom, record keeping is very inconsistent and hard to access so the deaths that have occurred are very hard to extract with such specificity. Then electronic/electrical classes are so rare that its hunting for a rare event in a tiny population and there may well have been no occurrences but that doesn't mean ignoring basic safety requirements is the right thing to do.

Electrocutions have and do occur in schools in the US:
http://www.thespectrum.com/story/news/local/2017/03/29/schs-student-severely-burns-himself-school-equipment/99787512/
http://www.delcotimes.com/article/DC/20100925/NEWS/309259991
https://www.cpsc.gov/s3fs-public/Electrocution-Report-2004-to-2013.pdf?V_9Zl10pv4Wz03uBPRx78IctKRABjYDv

But its teachers such as yourself lacking the most basic understandings of the material needed to teach it safely that is causing the ever increasing red tape and requirements upon which teachers need to attain before they can teach specialist topics (I know of people who're retired rather than going through the modern reassessments to be qualified to continue teaching what they've been doing safely for a lifetime). From what you've posed and the dismissive attitude to safety you're the worst of the worst, perhaps you'd like to confirm your current position and faculty?

110V is still able to deliver very dangerous fault conditions:

And you can't simply rely on breakers to solve all the problems:

Safety requires multiple layers of protection, single point failures should not leave a student in danger so even a circuit with a RCD/AFCI/GFCI (or combination there of) is still not enough to ensure safety.

Hope [sic] do you expect studnets to learn if they don’t experience life?
They should be learning in well planned courses with teachers/instructors who understand the material and can teach it safely. These experiences can be taught to students but not safely by you.

This is what happens when to try to over protect our children from leaning.
No, this is what happens when there are charlatans posing as concerned teachers.


Freind pelase read waht I wrote.  Your post is proff of what I have been saying.

Have you ever been shocked?
 

 

Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #81 on: February 04, 2018, 05:45:27 am »
When's the last time your students paid perfect attention to any of your lessons and came away with a 100% understanding? Treat youth like youth. Beginners are beginners. Take risks on your own time.
Even with explicit step by step instructions noted as essential for safety some students will ignore it anyway, and then complain if you try and eject them for being dangerous....   When there is safety involved it really requires one on one supervision.

Also, if you don't think you're going to be in the shit career-wise if one of your students gets shocked messing with the mains -- in or out of the classroom, and regardless of whether it kills them -- then you've got your head somewhere south of the books. And north of the ground.
I wouldn't let students anywhere near live mains, if they were doing some work with mains then it would be inspected before energizing and that would be inside an appropriate grounded/armoured/interlocked enclosure as appropriate. Teaching mains technology/coursework is often done with either low voltage analogs (24V AC etc) or completely insulated to the standards of consumer equipment so that there is no possibility of exposed shock hazards, as above voltages can be measured on appropriate step down transformers integrated into the benches or equipment, and currents by non contact methods all routinely hi-pot tested for breakdown/damage of the insulation. As much as some people dislike the shrouded banana plugs they sure made it easier to let students connect mains voltages.

Why are you so agaisnt studdnts learning?  By placing them in such as "safe": envoronemtn they aren't really learning are they.  Why not let them learn in an envoroment where they are supervised and shoudl something happen there are people who can assist.  Much better than having them along on a job site where they might be alone.

Friend you shoudl knoe 24 VAC can prduice voltates whcih can zap stedents.  So what's being gained? 

I will aslk you again, have you ever been shocked or zapped?

Please read my posts and respode to what I have written.
 








 

Offline imidis

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #82 on: February 04, 2018, 05:51:11 am »
If I had a choice, I would rather get zapped by 120V AC than a spark plug wire from a car. Home electrical I have no qualms about replacing anything electrical in the house, though I would absolutely draw a line at modifying the electrical panel.

When I was young, I mean really young I stuck my finger in a nightlight socket at of curiosity of how it worked. I didn't really learn anything other than it was a weird feeling.

In my younger years I assisted in plumbing and heating, it was a pretty valuable experience as it ranged from low voltages to higher. eg gas thermostat vs electrical heat thermostat. (AC, Heater)

In some situations I will work on live wires, in others I'm extremely cautious. Usually getting a marette on the live, whether active or not is first priority, just so if someone that doesn't know better doesn't have an incident, until the new (whetever it is) is installed.

In more deadly situations its good to have two testers (usually use non contact detector) to verify the circuit is not live.

Short circuit situations can be quite hazardous, breakers can vary in ratings. One thing I've always avoided is a short, also never giving voltage a path.

The ac jolt doesn't bother me that much but I wouldn't really suggest anyone try it.  :-//

There are some situations where it could be dangerous.

Around 20 years ago someone brought in a shock pen (we had rather nefarious pen thiefs around) and thought, if just the wrong person experienced that and had a fit, they would probably have a supervisor breathing down their neck.

I hated that job. We learned all this safety about, lockout, tagout, forklifts, had an operators license. However, once I got in that position it was one of those, well we can't follow those safety rules here. Warning signs about forklift traffic were ignored by the mechanics and engineers. Lucky none of them ever got killed. For those that don't know, forklifts literally have tons of counter weight. That would really ruin your day getting hit by one.
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Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #83 on: February 04, 2018, 05:52:41 am »
I guess I see the OP's point: when we are exposing kids to a new thing, it is important to show the two sides of the coin. Ideally this should be done in a controlled environment with all the appropriate warnings and no possibility of collateral damage, but that is impossible due to uncontrollable factors: liability, parents' reaction, equipment failure and that 0.01% chance that someone will have further health issues or death.

We certainly came from a different world, where we really experienced jolts, saw pliers or screwdrivers give up the holy ghost and rules and "responsible party" interference was much less present - we survived even after these zaps and jolts, but what about the ones who didn't? Statistics are cold and distant until it happens with someone close to you and that is why the overreaction/control exists today (some excessive, but still).

Thank you.  Any idea how many studnets have died for being zapped or an electrution in an electronics class?  We all know studednts have died at school.  But has there ever been one in an electrocins class?  What's the worst injury that can happen in an electrocnics class?  We can rule out death.  Maybe a slight burn?  Does being zapped cause perminent damge?  Don't think so.



 

 

Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #84 on: February 04, 2018, 06:10:43 am »
If I had a choice, I would rather get zapped by 120V AC than a spark plug wire from a car. Home electrical I have no qualms about replacing anything electrical in the house, though I would absolutely draw a line at modifying the electrical panel.

When I was young, I mean really young I stuck my finger in a nightlight socket at of curiosity of how it worked. I didn't really learn anything other than it was a weird feeling.

In my younger years I assisted in plumbing and heating, it was a pretty valuable experience as it ranged from low voltages to higher. eg gas thermostat vs electrical heat thermostat. (AC, Heater)

In some situations I will work on live wires, in others I'm extremely cautious. Usually getting a marette on the live, whether active or not is first priority, just so if someone that doesn't know better doesn't have an incident, until the new (whetever it is) is installed.

In more deadly situations its good to have two testers (usually use non contact detector) to verify the circuit is not live.

Short circuit situations can be quite hazardous, breakers can vary in ratings. One thing I've always avoided is a short, also never giving voltage a path.

The ac jolt doesn't bother me that much but I wouldn't really suggest anyone try it.  :-//

There are some situations where it could be dangerous.

Around 20 years ago someone brought in a shock pen (we had rather nefarious pen thiefs around) and thought, if just the wrong person experienced that and had a fit, they would probably have a supervisor breathing down their neck.

I hated that job. We learned all this safety about, lockout, tagout, forklifts, had an operators license. However, once I got in that position it was one of those, well we can't follow those safety rules here. Warning signs about forklift traffic were ignored by the mechanics and engineers. Lucky none of them ever got killed. For those that don't know, forklifts literally have tons of counter weight. That would really ruin your day getting hit by one.

Sounds like you've been zapped a few times.  Did it kill you as others are saying could happen?  And yes let's not forget about spark plugs.  If I recall correctly the voltage is either in the 20k old school or 40k volt range. 

Of course my students don't open up and play with the mains int he breaker pannel.  But at each student station they have a mains to plug things into.

I think we've all been zapped in our life time.  Sticking a pin an electrial outlet i think is something most of uss do when we are 3 or 4 years odd.  We are curious and want to know how things work.  We experiment and explore.

One of the other posters suggested using 24 volt.  Yes we could, but then what are we teaching our students.  Getting zapped with 24 volts is just not the same as 120vac.  Then in the workplace were an employeeds gets zapped with 120vac they are going say what happnd?  I never learned that in school.

I try to be the best teaching I can to these students.  I let them fail...  Why?  So they learn.  I would say 95% bof my fellow instructors wnat studnets to follow a strict set of instruction in the lab and don't let them deviate or try something on their onw.  Is that learning?  Or parrioting?  Studnets who finsih my class can think and have critial thinking skills?

What klind of emplouyee wound you want?  One who can think and solve probelms?  Or one who just follows a written set of instructions.



 



   

 

Offline imidis

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #85 on: February 04, 2018, 06:47:57 am »
Sounds like you've been zapped a few times.  Did it kill you as others are saying could happen?  And yes let's not forget about spark plugs.  If I recall correctly the voltage is either in the 20k old school or 40k volt range. 

Of course my students don't open up and play with the mains int he breaker pannel.  But at each student station they have a mains to plug things into.

I think we've all been zapped in our life time.  Sticking a pin an electrial outlet i think is something most of uss do when we are 3 or 4 years odd.  We are curious and want to know how things work.  We experiment and explore.

One of the other posters suggested using 24 volt.  Yes we could, but then what are we teaching our students.  Getting zapped with 24 volts is just not the same as 120vac.  Then in the workplace were an employeeds gets zapped with 120vac they are going say what happnd?  I never learned that in school.

I try to be the best teaching I can to these students.  I let them fail...  Why?  So they learn.  I would say 95% bof my fellow instructors wnat studnets to follow a strict set of instruction in the lab and don't let them deviate or try something on their onw.  Is that learning?  Or parrioting?  Studnets who finsih my class can think and have critial thinking skills?

What klind of emplouyee wound you want?  One who can think and solve probelms?  Or one who just follows a written set of instructions.

Obviously I'm still here.  :) But it is important to teach precautions and basics. I'm not really sure what the voltage was on those wires, but it felt unpleasant. I've worked on a lot of cars and I only let that happen once. It was that unpleasant.

Problem solvers good, but I'll never be an employer though.

I agree failure is the best way to learn. Just hopefully while avoiding costly mistakes. I push the boundaries of what I know, but nothing makes your heart sink more when you think maybe you've damaged a $16k piece of equipment. (this equipment was no touchy voltage unless fully drained otherwise deadly) I would not want to find out what that feels like. Otherwise I wouldn't be here.

Luckily I had the service manual, those are instructions I would not ignore. Got to know where to draw the line though.


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Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #86 on: February 04, 2018, 06:52:57 am »
Sounds like you've been zapped a few times.  Did it kill you as others are saying could happen?  And yes let's not forget about spark plugs.  If I recall correctly the voltage is either in the 20k old school or 40k volt range. 

Of course my students don't open up and play with the mains int he breaker pannel.  But at each student station they have a mains to plug things into.

I think we've all been zapped in our life time.  Sticking a pin an electrial outlet i think is something most of uss do when we are 3 or 4 years odd.  We are curious and want to know how things work.  We experiment and explore.

One of the other posters suggested using 24 volt.  Yes we could, but then what are we teaching our students.  Getting zapped with 24 volts is just not the same as 120vac.  Then in the workplace were an employeeds gets zapped with 120vac they are going say what happnd?  I never learned that in school.

I try to be the best teaching I can to these students.  I let them fail...  Why?  So they learn.  I would say 95% bof my fellow instructors wnat studnets to follow a strict set of instruction in the lab and don't let them deviate or try something on their onw.  Is that learning?  Or parrioting?  Studnets who finsih my class can think and have critial thinking skills?

What klind of emplouyee wound you want?  One who can think and solve probelms?  Or one who just follows a written set of instructions.

Obviously I'm still here.  :) But it is important to teach precautions and basics. I'm not really sure what the voltage was on those wires, but it felt unpleasant. I've worked on a lot of cars and I only let that happen once. It was that unpleasant.

Problem solvers good, but I'll never be an employer though.

I agree failure is the best way to learn. Just hopefully while avoiding costly mistakes. I push the boundaries of what I know, but nothing makes your heart sink more when you think maybe you've damaged a $16k piece of equipment. (this equipment was no touchy voltage unless fully drained otherwise deadly) I would not want to find out what that feels like. Otherwise I wouldn't be here.

Luckily I had the service manual, those are instructions I would not ignore. Got to know where to draw the line though.

Glad you are still with us.  I agrree with you it all comes down to education.

 
 

Offline Electro Detective

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #87 on: February 04, 2018, 08:44:20 am »
Apparently not many have copped a nice 'can't let go...'  240 volt ZAP  :o

nor had hot copper or brass shrapnel fly at their eyes from an active to neutral short   :scared:

or taken out an oscilloscope, fried it's croc ground clip and blow the mains breaker (if it tripped with correct rating)    :-[


Perhaps 120 volts is a safer voltage to work with, and less chance of DIY adventurous home student barbeque  ?  :-//


 
 
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Offline CharlieEcho

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #88 on: February 04, 2018, 03:41:03 pm »
Sure, 120VAC is marginally safer than 240, but 120 is enough to do serious damage. And when I was shocked as a kid by clumsily bridging the terminals while rooting around in a floodlight-timer box, it was enough to convulse the fingers I had extended into it. I remember having to pull my hand away by rotating my shoulders. Bad and scary.

As has been said multiple times, the question isn't whether this is safe to do for OP, but rather wise to demonstrate to totally uninitiated students.

If the point is to demonstrate the properties of AC then stepping down the voltage is the responsible thing to do, at minimum.   (And even then, I don't like that it's coming from the utility service vs. a more tightly regulated lab AC source.)
« Last Edit: February 04, 2018, 03:56:03 pm by CharlieEcho »
 

Offline rsjsouza

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #89 on: February 04, 2018, 06:08:35 pm »
I guess I see the OP's point: when we are exposing kids to a new thing, it is important to show the two sides of the coin. Ideally this should be done in a controlled environment with all the appropriate warnings and no possibility of collateral damage, but that is impossible due to uncontrollable factors: liability, parents' reaction, equipment failure and that 0.01% chance that someone will have further health issues or death.

We certainly came from a different world, where we really experienced jolts, saw pliers or screwdrivers give up the holy ghost and rules and "responsible party" interference was much less present - we survived even after these zaps and jolts, but what about the ones who didn't? Statistics are cold and distant until it happens with someone close to you and that is why the overreaction/control exists today (some excessive, but still).

Thank you.  Any idea how many studnets have died for being zapped or an electrution in an electronics class?  We all know studednts have died at school.  But has there ever been one in an electrocins class?  What's the worst injury that can happen in an electrocnics class?  We can rule out death.  Maybe a slight burn?  Does being zapped cause perminent damge?  Don't think so.
Just like you, I don't know about these statistics. Slight burns and shocks are consequences of the learning experience, and several reports and some interesting movies about electricity safety (which could be shown in a class) can be seen in the thread below.

https://www.eevblog.com/forum/chat/electric-shock-experiences-for-those-still-alive/

Long term consequences of electrical shocks were subject of study of a professor in Brazil that was able to find some correlation with kidney and cardiac abnormalities months after the shock - unfortunately I couldn't find the reference (this was long before the internet).

Regardless, several safe experiments that showcase electrical stimulus (stopping short of an actual shock) are not unheard of. Also, the Harbor Freight freebie meters can also be turned into another controlled experiment that showcases the power of electricity and misuse of test equipment. The charged capacitors become an experiment that shows the dangers lingering inside modern equipment and their switching power supplies. Heck, you could even show some of ElectroBoom's videos for ideas.

One thing you can't control (nobody really can) is if a more enthusiastic student decides to reproduce these at home without the same level of safety - but that would be very circumstantial.
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Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #90 on: February 04, 2018, 07:09:11 pm »
I guess I see the OP's point: when we are exposing kids to a new thing, it is important to show the two sides of the coin. Ideally this should be done in a controlled environment with all the appropriate warnings and no possibility of collateral damage, but that is impossible due to uncontrollable factors: liability, parents' reaction, equipment failure and that 0.01% chance that someone will have further health issues or death.

We certainly came from a different world, where we really experienced jolts, saw pliers or screwdrivers give up the holy ghost and rules and "responsible party" interference was much less present - we survived even after these zaps and jolts, but what about the ones who didn't? Statistics are cold and distant until it happens with someone close to you and that is why the overreaction/control exists today (some excessive, but still).

Thank you.  Any idea how many studnets have died for being zapped or an electrution in an electronics class?  We all know studednts have died at school.  But has there ever been one in an electrocins class?  What's the worst injury that can happen in an electrocnics class?  We can rule out death.  Maybe a slight burn?  Does being zapped cause perminent damge?  Don't think so.
Just like you, I don't know about these statistics. Slight burns and shocks are consequences of the learning experience, and several reports and some interesting movies about electricity safety (which could be shown in a class) can be seen in the thread below.

https://www.eevblog.com/forum/chat/electric-shock-experiences-for-those-still-alive/

Long term consequences of electrical shocks were subject of study of a professor in Brazil that was able to find some correlation with kidney and cardiac abnormalities months after the shock - unfortunately I couldn't find the reference (this was long before the internet).

Regardless, several safe experiments that showcase electrical stimulus (stopping short of an actual shock) are not unheard of. Also, the Harbor Freight freebie meters can also be turned into another controlled experiment that showcases the power of electricity and misuse of test equipment. The charged capacitors become an experiment that shows the dangers lingering inside modern equipment and their switching power supplies. Heck, you could even show some of ElectroBoom's videos for ideas.

One thing you can't control (nobody really can) is if a more enthusiastic student decides to reproduce these at home without the same level of safety - but that would be very circumstantial.

I've been thinking about this a bit more.  Our high schools and colleges teach welding.  While in electronics we try not to heat metal to it's melting point in welding they do.  I suspect there are far more burns and injuries in welding than electronics. 

At all of the local elementary schools they have a gardening program.  What could be safer, than a class of kids gardening right?  One little girl was stung four times by bees.  What's worse, being zapped by 120 vac or 4 bee stings?

Our schools are dangerous places, but then so is the world.  Our schools are preparing students for life in the "dangerous" world.  The way students learn is by making mistakes.  And I can tell you no matter how much safety training students receive they think they are smarter and something bad is not going to happen to them when they do something stupid.

Having a piece of hot welding slag causing a burn, bee stings in the garden, or getting zapped is all part of the learning process.

If you were hiring a new employee wouldn't you want someone who had been jolted a few times?  Means they made some mistakes and hopefully learned something.  Our would you want someone who completed each lab exercise step by step which resulted in the perfect outcome?  (Kind of like making a TV dinner.)  I guess what I'm asking is if I were teaching students to be cooks.  I could teach them to follow instructions which would make them perfect cooks for the fast food business.  But wouldn't your rather want to hire a cook has experimented a bit?

Look I'm just the professor truing to give this "kids" the best educational experience I can.







 




Bee stings
 

Offline Fungus

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #91 on: February 04, 2018, 07:39:49 pm »
One of the other posters suggested using 24 volt.  Yes we could, but then what are we teaching our students.  Getting zapped with 24 volts is just not the same

Thread over.

 

Offline Electro Detective

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #92 on: February 04, 2018, 10:13:29 pm »
One of the other posters suggested using 24 volt.  Yes we could, but then what are we teaching our students.  Getting zapped with 24 volts is just not the same

Thread over.

In the US, they might learn better if zapped with 12 volts AC, and advised the 120v mains will be be 10 times more 'shocking' and or lethal 

It's safer (cough...) and the x10 math is easier to remember too


In 240 volt Australia, 24 volts AC is still sort of ok to play with and easy on the math too,
but just remember when playing with it   "If you drink and DIY, you're a bloody idiot..."    

;D

 

Online rstofer

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #93 on: February 04, 2018, 10:17:39 pm »
I would think that having students working on voltages over 50V would be considered reckless endangerment.

It's one thing for my father to teach me, that's family.  But students are somebody else's family and in our litigious society having them work on mains voltages exposes everybody in the food chain, including the local taxpayers, to enormous financial risk.

And for what?  Just because we can?  There is absolutely nothing to gain by this.

At the high school level (and below), I would probably limit things to 4-AA batteries or less and definitely no LiPo batteries.  Maybe all the way up to 9V wall warts but that's the limit.  College level I would probably go all the way to 50V DC. 

College level Industrial Technician classes are the exception of course.  There we can get serious about electrical systems.

There are plenty of things to learn that don't involve jamming probes into wall outlets.


« Last Edit: February 04, 2018, 10:19:41 pm by rstofer »
 
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Offline Electro Detective

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #94 on: February 04, 2018, 10:29:15 pm »
Personally, if it was my class of shifty, impish, risk taking, pretend nerd, prank pulling 'good keen students'  litigious little Fers   >:D >:D >:D

it would be a a LOT safer to sit them down and watch an afternoon of 'ElectroBOOM' Youtubes,

and once the giggling subsides

some Fluke flashover and related youtube videos  :o :o :o


before hitting the lab benches    :scared:
« Last Edit: February 04, 2018, 10:31:02 pm by Electro Detective »
 

Offline Fungus

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #95 on: February 04, 2018, 10:31:19 pm »
There are plenty of things to learn that don't involve jamming probes into wall outlets.

This.
 

Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #96 on: February 04, 2018, 11:26:09 pm »
The responses are interesting.  You know I do have the option of teaching students with virtual equipment. Using virtual lab equipment, DMMs, scopes, signal generators there would be no possible way for the students to get inured or zapped.  The student use virtual probes and attach them to virtual chips all while remaining completely safe.  I've talked to employers who have interviewed students who have graduated from programs where they used virtual equipment.  They tell me they won't hire these graduates because they don't even know how to turn the dial on a physical multi-meter or which way to turn a screw driver to loosen a screw. 

Are those the kind of skills you would like your fellow workers to have?
 

Offline ghpicard

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #97 on: February 04, 2018, 11:40:00 pm »
I've talked to employers who have interviewed students who have graduated from programs where they used virtual equipment.  They tell me they won't hire these graduates because they don't even know how to turn the dial on a physical multi-meter or which way to turn a screw driver to loosen a screw. 

Are those the kind of skills you would like your fellow workers to have?

I'm absolutely sure that having being exposed to unsafe operating conditions (and training) won't get the job for them either. A person whose safety understanding is lacking is more a liability than an asset to any company.
 
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Offline daybyter

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #98 on: February 04, 2018, 11:53:54 pm »
https://www.google.de/url?sa=t&source=web&rct=j&url=http://www.educator-resources.com/pdf/Teacher%2520Tort%2520Liability.pdf&ved=2ahUKEwjl68eNuY3ZAhVRJewKHQvABooQFjAAegQIERAB&usg=AOvVaw2mJgi39wy1AwntLLTlEXkD

You might make it on national TV? I wonder if rigol is happy if their product is featured in such a case?

But since there is always a slim chance, that one of the kids has a heart problem, so your zapping idea might be this kids terminal experience.

Instead I would go to your boss and ask if (s)he is ok, if you hit the kids with a whip. That seems less dangerous to me.
 

Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #99 on: February 05, 2018, 01:38:17 am »
I've talked to employers who have interviewed students who have graduated from programs where they used virtual equipment.  They tell me they won't hire these graduates because they don't even know how to turn the dial on a physical multi-meter or which way to turn a screw driver to loosen a screw. 

Are those the kind of skills you would like your fellow workers to have?

I'm absolutely sure that having being exposed to unsafe operating conditions (and training) won't get the job for them either. A person whose safety understanding is lacking is more a liability than an asset to any company.

What is unsafe?  Why do you think these students aren't receiving proper safety training?  Or being exposed to unsafe conditions?
 
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