Author Topic: With a budget of $400 - Rigol or Siglent scope?  (Read 16586 times)

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Offline kcbrown

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #175 on: February 22, 2018, 08:36:13 pm »
If the risk is unnecessary and, as here, doesn't even give you any advantages at all, then why in the world would you take it anyway?    Surely that would be irrational, no?


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Offline ebastler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #176 on: February 22, 2018, 08:42:06 pm »
You folks are all saying a kid getting zpped with 120 is going to kill them.  I'm just asking for one exapmle of were it has bapped.

First, I don't think anybody suggested that it "will" kill them, or even that it is likely to do that. The point is that, while it is very unlikely to be fatal, it is not unlikely enough to justify that you simply accept this possibility.

Given the most severe potential outcome -- death of someone you have taken responsibility for -- you need to do more to minimize the probability even further, to make the probability * severity product acceptable.

Quote
I'm sure many people in the fourms have been zapped.  It's all just part of learning.  Yes we know what we are doing but accidents do occur sometimes.  Even Dave said he had a multimeter blow-up in his hand.  Is he dead, did he get seriouly hurrt or burned.....  Nope.

Given the odds and the asymmetrical outcome, how can you propose this "learning gamble" to your students, their parents, and the school?

If 1000 students learn a valuable lesson (and another 1000 forget it right away, and another 1000 become even more reckless with electricity), and one is left dead in the process, would you consider that OK in the balance? What multiplier on the positive outcomes would it take to make you say "Sure, it killed one of them, but look at the valuable lesson many of the others learned." ?!
 
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Online Fungus

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #177 on: February 22, 2018, 09:12:44 pm »
Yes treat electricty with respecct, but no need to scare people about it either?

When I'm teaching I always treat it with 10x normal respect because I know for a fact that pupils only absorb a small fraction of anything a teacher says.
« Last Edit: February 22, 2018, 09:14:22 pm by Fungus »
 

Offline ArthurDent

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #178 on: February 22, 2018, 09:37:00 pm »
Let me summarize this thread. We have someone who describes himself, at best; as a tinkerer who has been teaching cybersecurity as a college professor in classrooms for 15 years; who wants to teach hands-on electronics to children; who believe that safety is optional; but freely and continually spouts his political views throughout his posts; and is unwilling to listen to others with experience who have explained in detail the flaws in his ‘method’.  To excuse the pun, I think this class is beyond his scope.

Experience isn’t the best teacher because you get the exam first then the explanation after and suggesting measuring line voltage with a scope with his skill level is just idiotic. I am thankful he didn’t decide to teach firearms safety.
 

Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #179 on: February 23, 2018, 04:22:55 am »
According to this article: http://www.ecmweb.com/content/case-120v-electrocution-mystery

In 1999, 278 workers died from electrocution.
1/3 were high voltage incidents, the remaining were 120V

If you want to contribute to the next generation of statistics, go ahead. I will judge you as a fool though.

The reason there are no readily available examples of students being electrocuted is that there are very few educators moronic enough to expose their students to unnecessary risks.

Amazing, why have there been no deaths since 1999?  That's incredible.
But here's the real question, why 278 professionals die from electrocution?  Were they not trained properly? 

How do these students learn?  I've seen suggestions to teach students who will be working with high voltage using low voltage.  Are you suggesting they learn how to work with high voltage on the job?  I can't imagine any employer would hire anyone to work on high voltage that's never been exposed to high voltage before.

Why would you not want students to learn how to work with high voltage in a controlled safe environment where they are being closely monitored? 

Again I will ask has there ever been and electrocution death or serious injury
 

Offline Dubbie

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #180 on: February 23, 2018, 04:50:06 am »
Of course there have been deaths since then. That was the statistic cited in the paper. Thankfully the yearly death toll has been decreasing. This has been attributed to better education, better standards and regulations and new technology such as RCDs.

As to your last question, I answered that already. There are very few teachers foolish enough to let students get “educational zaps” so therefore, students don’t die. See how that works?
 

Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #181 on: February 23, 2018, 05:05:36 am »
Of course there have been deaths since then. That was the statistic cited in the paper. Thankfully the yearly death toll has been decreasing. This has been attributed to better education, better standards and regulations and new technology such as RCDs.

As to your last question, I answered that already. There are very few teachers foolish enough to let students get “educational zaps” so therefore, students don’t die. See how that works?

Sorry I don't.  I think you will find at many science museums educators let children get zapped.  I know when I was in school many of the students were curious about electricity and zapped themselves.  A popular science project at schools is a zapper.  (Home made step-up transformer.)

This is called learning.  Are you trying to tell me you have never been zapped?   
 

Offline Dubbie

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #182 on: February 23, 2018, 05:38:31 am »
Stop being deliberately dense. A high voltage current limited zap like a stun gun or electric fence is not comparable to a mains shock with the potential to supply tens or hundreds of amps of current.
 

Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #183 on: February 23, 2018, 06:31:00 am »
Stop being deliberately dense. A high voltage current limited zap like a stun gun or electric fence is not comparable to a mains shock with the potential to supply tens or hundreds of amps of current.

Dude do you really think student in a classroom would have access to mains with tens or hundreds of amps of current?  You obviously do which is why you said it.  Maybe that was the case where you went to school, but that's not the case in my classroom.
 

Offline kcbrown

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #184 on: February 23, 2018, 07:44:13 am »
Dude do you really think student in a classroom would have access to mains with tens or hundreds of amps of current?  You obviously do which is why you said it.  Maybe that was the case where you went to school, but that's not the case in my classroom.

What amount of current are the power sockets in your classroom rated for, and what are the breakers set to trip at?   If it can power a typical hair dryer then you're looking at 10 amps or more.

So I'm REALLY skeptical of your claim that the mains sockets in your classroom can't source current in the 10 amp or greater range.




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Online Fungus

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #185 on: February 23, 2018, 10:49:53 am »
Dude do you really think student in a classroom would have access to mains with tens or hundreds of amps of current?  You obviously do which is why you said it.  Maybe that was the case where you went to school, but that's not the case in my classroom.

Who cares? There simply shouldn't be bare pieces of metal around the place that are connected to AC mains. It's not necessary. The quality of teaching won't improve because of it, you're not "preparing them for the real world" in any way.

I really don't see why that's difficult to understand.
 
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Offline ebastler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #186 on: February 23, 2018, 02:52:47 pm »
Seems to me that we can end the discussion at this point. DougSpindler has dug in his heels so firmly, I would be utterly surprised to see any of our arguments getting through.

Good luck, Doug. Before you start the class, I recommend full disclosure of your "learning through painful experience" concept to the students, parents, and school; I'm sure they will be delighted. And while you have their attention, make them sign waiver forms...
 
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Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #187 on: February 23, 2018, 04:29:25 pm »
I've been teaching for over 20 years so it's not like you are going to change my mind or the way I teach UNLESS there is a reason I should do something different.

While I appreciate everyone's input my students are the product I'm producing.  Many have told me they like my teaching style and appreciate the real world lab exercise situations I give them.   

In my 20 years+ of teaching not one of my students has died or been serious injured.  Yes a few over the years have been zapped but no permanent or long term injuries. 

Over the years I have had a few students who tell me EMI/RFI cause brain cancer, and a wide variety of other diseases.  They have even brought me books, which I have read and researched and found all of the research to be less than credible. 

You "guys" keep saying someone in my class is going to get killed, yet no one can provide even one case of where a student was killed in an electronics class at school.  Yes electricity is dangerous and needs to be treated with respect but there's not need to scare people about it.

 

Offline donkey77

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #188 on: February 23, 2018, 08:43:11 pm »
Part of me thinks that you, Doug, are just trolling and you are actually the age of these students you say you teach.
If not I'm pretty scared that people like yourself can be allowed to teach with the attitude you have. Putting the safety concerns aside for a minute the mixture of lack of knowledge, teaching by some youtube video and the lack of basic spelling and punctuation, I feel you are doing your students a dis-service. Add in the stubborn arrogance that you have shown to those, in my opinion, better qualified than yourself, makes you a liability to those in your care.
I would be interested how you would feel showing this thread to your superiors at the school/parents, and what their opinion is regarding letting you loose on their children/students!
 

Online Someone

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #189 on: February 23, 2018, 11:01:08 pm »
I would be interested how you would feel showing this thread to your superiors at the school/parents, and what their opinion is regarding letting you loose on their children/students!
And thats the simple point, an academic would be happy to have their work critiqued and shared publicly but this person wont disclose their affiliations, qualifications, or faculty where they are supposedly teaching.

Are there any members in the bay area of the US willing to spend a little time on the phone calling around? It should be easy enough to verify their current employment.
 

Online Someone

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #190 on: February 23, 2018, 11:13:00 pm »
You "guys" keep saying someone in my class is going to get killed, yet no one can provide even one case of where a student was killed in an electronics class at school.  Yes electricity is dangerous and needs to be treated with respect but there's not need to scare people about it.
Its a high risk environment with a small number of people in it, just like the US claimed proudly for a long time they never lost an Astronaut in space. That doesnt make space travel safe, and mains power is known to be dangerous with students in schools being killed without even entering the additional risks of an electronics class.

You can't prove no student has ever died in an electronics class, while we can prove students are dying from exposure to mains power. Its these ridiculous "arguments" you put which make you claim of being a serious/experienced teacher laughable, basic logic can quickly disassemble your points and reduce your arguments to misguided hubris .

I've been teaching for over 20 years so it's not like you are going to change my mind or the way I teach UNLESS there is a reason I should do something different.
Teaching electronics for 20 years and still don't understand the basics of measurement technology? Sounds like you've been teaching unrelated courses for many years and assume you can apply that experience to an unrelated field (which has real and immediate physical dangers to the students). If you're so confident in your teaching and coursework and have the support of your peers and faculty why wont you reveal who they are?
 

Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #191 on: February 24, 2018, 03:54:35 am »
I would be interested how you would feel showing this thread to your superiors at the school/parents, and what their opinion is regarding letting you loose on their children/students!
And thats the simple point, an academic would be happy to have their work critiqued and shared publicly but this person wont disclose their affiliations, qualifications, or faculty where they are supposedly teaching.

Are there any members in the bay area of the US willing to spend a little time on the phone calling around? It should be easy enough to verify their current employment.

Intereitng comment from someone who hides behind the name "someone".  Is there a reason you don't use your real name?  At least I use my real name and have told you where I teach and live.  Any reason you fail to do the same?   

Silly "someone", I'm teaching at a public college my name, teaching qualification and where I teach are all a metter of public recored.

If you would stop bashing teahcers you would find I am an award winning instructor and two of my students have been recogined for their acheivments (what I taught them) by the Preseidnt of the United States.

Can you say the same?  Or are you one of those people that just goes arond basing teachers who do a good job?
 

Online Someone

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #192 on: February 24, 2018, 06:31:58 am »
I'm teaching at a public college my name, teaching qualification and where I teach are all a metter of public recored.
But you wont share this information when asked (now several times)?
 

Offline Electro Detective

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #193 on: February 24, 2018, 09:52:52 am »

Intereitng comment from someone who hides behind the name "someone".  Is there a reason you don't use your real name?  At least I use my real name and have told you where I teach and live.  Any reason you fail to do the same?   

Silly "someone", I'm teaching at a public college my name, teaching qualification and where I teach are all a metter of public recored.

If you would stop bashing teahcers you would find I am an award winning instructor and two of my students have been recogined for their acheivments (what I taught them) by the Preseidnt of the United States.

Can you say the same?  Or are you one of those people that just goes arond basing teachers who do a good job?


'Doug' your comment above has to be some sort of record here at this forum for sudden grammar gone south   :clap:

Sorry to be 'that guy' to point it out, but just look at it   :o 


Did somebody accidently spill vodka or grappa onto the keyboard while the speech recognition program was running?  ;D

« Last Edit: February 24, 2018, 10:02:39 am by Electro Detective »
 
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Offline DougSpindler

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #194 on: February 25, 2018, 05:14:03 pm »

Intereitng comment from someone who hides behind the name "someone".  Is there a reason you don't use your real name?  At least I use my real name and have told you where I teach and live.  Any reason you fail to do the same?   

Silly "someone", I'm teaching at a public college my name, teaching qualification and where I teach are all a metter of public recored.

If you would stop bashing teahcers you would find I am an award winning instructor and two of my students have been recogined for their acheivments (what I taught them) by the Preseidnt of the United States.

Can you say the same?  Or are you one of those people that just goes arond basing teachers who do a good job?


'Doug' your comment above has to be some sort of record here at this forum for sudden grammar gone south   :clap:

Sorry to be 'that guy' to point it out, but just look at it   :o 


Did somebody accidently spill vodka or grappa onto the keyboard while the speech recognition program was running?  ;D

You do have a valid point.  My reply was written on a small screen device, with a funky auto-correct/spell checker while I was driving my car.  To pay homage to Mark Twain....  I’m sorry I did not have the time to make my post shorter of correct the spelling pr grammar. 

But here’s the think...  does it really matter?  “Someone” has become a troll and has an agenda which apparently included bashing instructors and has nothing to do with the original post or subsequent questions.  If “someone” were posting serious meaningful posts I would take the take to provide grammatically correct responses.

I will say this again, I really would like to thank those whol provided meaningful quality responses to my original question.  I might be an instructor/profesor but I tool am always learning.  Most of the folks here have given me wonderfull information which I’ve already used in my classroom and on conference calls with other instructors so they will teach their studnets.

As i stated previously it’s been decades since I have used a scope so being a buy one to use as a demonstration device in the classroom will be a real treat for my studnets.  I teach computer networking so now I will be able to show my studnets the actual network signals and even decode one or two.

What “someone” may not understand is when one works with networking equipment one is not always working with low voltages.  Studnets are working wth 48 vdc and mains or 120/208 and 220vac.

For the past 20 years the $8,00 eBay multimeters have been fine.  (Although someone is telling me they aren’t safe and one my studnets is going to get killed).  Well that has not happened.  In all my years of teaching I have never had even one student get seriously injured.  Worst injury is getting poked with a screwdriver, getting pinched with a pair of pliers or getting zapped.  I think the worst injury I have seen in 25 years in a technology class is a paper cut.  Now I’m sure someone is going to say I’m irresponsible for using paper in my class and that a studnet could die form getting cut and infected.  Yes that is possible and I am sure it happens but the reality is many of these kids if they were not in school would be doing other things more risky LSU he as stealing copper wire from street lights in our campus parking lot.  (Yup, that has happed 3 times so far).  At least if they take my class they will be able to use a voltage probe and multimeter to test the wire to see if it is energized befor they cut it.  I think this would make someone happy knowing I might be saving the life of a thief who is stealing copper wire.

     


 

Offline rogermanlleu

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #195 on: February 25, 2018, 07:12:01 pm »
Be careful, a wire might not have "voltage", i.e. being at earth potential, until you cut it! I suspect many copper thieves have died cutting the neutral wire of a live circuit.
 

Offline The Soulman

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #196 on: February 25, 2018, 07:47:27 pm »
My reply was written on a small screen device, with a funky auto-correct/spell checker while I was driving my car.

I don't like to insult people but I'd call you one irresponsible individual (at best).
 

Online nctnico

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #197 on: February 25, 2018, 08:34:46 pm »
My reply was written on a small screen device, with a funky auto-correct/spell checker while I was driving my car.

I don't like to insult people but I'd call you one irresponsible individual (at best).
Unfortunately people texting while driving usually don't drive their car into a tree.  :--

Note to self: when in the US find Doug and zap him ten times!  >:D
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline Simon

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Re: With a budget of $400 - Rigol or Siglent scope?
« Reply #198 on: February 25, 2018, 09:11:54 pm »
Well I think if Mr Spindler has not learnt what he needs to know sofar no more discussion will make any difference anyway. I think it's time to draw this one to a close.
https://www.simonselectronics.co.uk/shop
Varied stock of test instruments and components including EEVblog gear and Wurth Elektronik Books.
Also, if you want to get ripped off: https://www.ebay.co.uk/usr/simons_electronics?_trksid=p2047675.l2559
 
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