Author Topic: Beginners and beginner questions, why the disparity in answers?  (Read 9180 times)

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Offline LightagesTopic starter

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Beginners and beginner questions, why the disparity in answers?
« on: September 14, 2017, 08:34:50 pm »
I see this over and over again. Some new person comes here and asks a question on what they should buy.

Sorry to the beginners for the messy answers you get.

Everyone here is a unique person with different experiences and also lack of experiences. This is a highly mixed bag of cultures here and a highly mixed bag of personalities. The signal to noise ratio is higher here than many other forums on the internet but this still is the internet. I have feet in to two cultures, Canadian and South American. I can see the difficulties in trying to weed out what you need to pay attention to.

I have my advice to give for the beginner to take into account when reading the messy response they might get to an innocent question:

1. Please don't take anything personally ever said in response to your question. The mix of cultures here make not offending someone, unintentionally, impossible.

2. If you don't give location, level of experience, and budget, then expect wild variations in recommendations and price levels. Nobody can guess where you are starting or what is available in your area if we don't know. This will confuse you and maybe make you think all of us are idiots.

3. Expect completely opposite recommendations to what you think you should do or buy. You are a beginner and those who have already gone through the process only want to save you the wasted money and frustration of following the same trap they did. Try and follow the advice and swallow your pride.

4. Ignore post counts for responders. Just because someone here has 2000 posts means nothing. If you want to know whether to trust their opinion or not, look at some of their posts and see if it is just noise or well thought out responses. This isn't 100% effective but post counts by themselves mean nothing.

5. The moment you hear or see someone say, "don't worry about safety", WORRY! Safety ratings on equipment exist for a reason. Someone has been injured or killed to cause an investigation and recommendations in a change in safety standards so as to help prevent it occurring again. What are the chances that it will happen to you? Who knows? Do you really want to find out?

6. "I have done that a million times and nothing happened to me".  This is the most stupid excuse to ignore safety that you can read. What that person is trying to tell you is that because they never had a problem, nobody else has and never will. Ignore them. Ignore them just like you ignore people who say they never had a car accident so they never happen.

7. In the end, it is your money. Buy what you can with your budget. But if you ask for advice, then please at least take the advice in consideration even if you don't buy what is recommended. Don't feel inferior or bad that you purchased what you could. Just take the advice on how to use it.
« Last Edit: September 14, 2017, 08:40:14 pm by Lightages »
 
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Online Benta

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #1 on: September 14, 2017, 09:19:46 pm »
Quote
4. Ignore post counts for responders. Just because someone here has 2000 posts means nothing. If you want to know whether to trust their opinion or not, look at some of their posts and see if it is just noise or well thought out responses. This isn't 100% effective but post counts by themselves mean nothing.

Amen!
 

Offline brucehoult

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #2 on: September 14, 2017, 09:25:54 pm »
Shorter version:

- there's more than one right way to do anything, many approaches will work, everyone knows different things and recommends the way they know.

- there's plenty of wrong ways to do something too. If everyone agrees something is wrong, it probably is.

- As a professional programmer with 30+ years experience, working for a major international company, I often get directly approached by computer or programming beginners for advice. The number who take it is very small. Most do what they'd already decided anyway.
 

Offline LightagesTopic starter

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #3 on: September 14, 2017, 09:34:16 pm »

- there's plenty of wrong ways to do something too. If everyone agrees something is wrong, it probably is.


I would say the vast majority rather than everyone.
 

Offline Brumby

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #4 on: September 14, 2017, 11:55:24 pm »
What Lightages has said is very true - and it extends beyond purchase recommendations.

Very often, a beginner will come here with a simple question and find a number of responses are offered.  Some of these responses present information that may well be accurate - but is potentially for too technical for the beginner to understand.  Sometimes responses may go off on a tangent and the person who asked the question might be scratching their head when trying to understand what is being said - and how it relates to their inquiry.

This is not uncommon - unfortunately - and is just another aspect of the differences between members ... and the tendency for the "engineering mind" to latch onto the familiar parts of a topic and share - sometimes forgetting the specific question being asked and/or the skill level of the person who asked it.

You might also find some members responding rather intensely and this can be for a number of reasons.  It may just be their personality or it may be a subject about which they have a very strong opinion.  Sometimes these strong opinions can come from experiences that have been near misses - or had unfortunate outcomes.

The point about post count is also valid.  Big numbers just mean the member has a lot to say (oops  :-[ ) - it doesn't necessarily mean that what they say is any better (or worse) than anything said by others.  You might need to do a bit of homework to see how much weight you might put on their contributions, especially if they have an opinion which differs from the general tone of responses given.

One last point - and, I would argue, the most important - is that there is a wide range of experience available here.  From people who have spent their entire lives working in various industries - power, communications, control systems and so on - to people who only picked up a soldering iron this morning.  All of them will have an opinion and some of those will be shared here.  Finding the good advice from the less-than-helpful is important.  Usually other responses will guide you - but it is an exercise in awareness that you should always keep in mind.


Just remember, the vast majority of members here genuinely want to help - but being of the engineering mind, sometimes the social subtleties may escape us from time to time.
« Last Edit: September 14, 2017, 11:58:20 pm by Brumby »
 

Offline DimitriP

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #5 on: September 15, 2017, 12:59:45 am »
When someone asks "Which chainsaw" to buy, the correct answer is "Don't".

For everything less damaging than that, we end up with 5-35 page threads almost e v e r y time someone needs a set of probes, multimeter (god forbid:  oscilloscope)
signal generator, underware ,shoelaces, car tires or a new girlfriend.
Yes I included some future "which one to get" there :)


   If three 100  Ohm resistors are connected in parallel, and in series with a 200 Ohm resistor, how many resistors do you have? 
 
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Offline Assafl

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #6 on: September 15, 2017, 08:44:36 am »
One of the problems is the way questions are asked. What NOOBs probably want (but rarely ask for) is what those of us who are in the hobby did when we started.

Instead they ask for opinions. Not what we did - but knowing what we now know what we would have done. Not the same thing.

I own an Energy Gossen. It is a nice meter and it works reasonably well. Can I recommend it to a NOOB? Yup (it even shutters the inputs so a NOOB can't make a mistake). But would someone (even a hobbyist) to buy a 1k$ DMM? Hell no.

I started with a Beckman DM25 (actually after I had experience using my Fathers Micronta and VTVM). Do I use a scope? Yes. Did I use one in the 80's? Not really. I had a vacuum tube audio band one I used infrequently.

The best answer is what we ACTUALLY did. And what our lessons were. Nothibg spiritual or whatif needed.
 

Offline LightagesTopic starter

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #7 on: September 15, 2017, 09:30:45 pm »
I also think the problem is how we "experts" answer the question. A beginner asks a question and we all dog pile on with minutia. A beginner needs a simple answer that works. He/She doesn't need to read tomes on the philosophy of how the type of insulation in his test leads are good down to -10° or if the banana plugs have split posts or lantern types. She/He doesn't want to see pages of debates on safety ratings and who is UL listed or not.

What a beginner needs to see is united front when it comes to seeing recommendation on safety, quality, and what NOT to buy. When we get into pissing contests about who should buy a real CATIII meter and who should not, I am sure it scares them away.

Beginners do not know, BEGINNER. You can't tell them they should know their limitations. That is idiotic. The reason they are beginners is that they know nothing or not very much. Therefore we. as the experienced, need to recommend things that require less knowledge to be relatively safe and/or not throw money in the toilet.

So, IMHO, when a beginner asks for a recommendation for a multimeter, the response should not be "Get this $5 ebay multimeter but stay away from dangerous stuff". How the f#$% is a beginner supposed to know what is dangerous or not? This is irresponsible advice and can actually hurt someone. At the very least it can lead to bad readings and/or loss or money due to bad readings.

I believe that a beginner needs a multimeter that will help protect against any stupid mistake, beginner or not. If a beginner has a multimeter and is tempted to use it to test the wall outlet for his electric clothes dryer, he/she needs a multimeter that is CATIII, full stop. If the only meter on hand is a DM830 that costs $5 from ebay and he /she thinks it is OK to use because some idiot on the internet says to use it, good luck to the user if he/she has it connected in current mode by mistake.

So as "experts", we need to stop looking at things like we look at them. Recommend the lowest common instrument that is not going to be a problem for a beginner, or shut up.

One last thing for now. Stop calling beginners NOOBS. It is an insult to some and makes them shut down or leave.
« Last Edit: September 15, 2017, 09:32:27 pm by Lightages »
 
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Offline Seaofdep

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #8 on: September 15, 2017, 09:51:23 pm »
Thanks for this , being a beginner myself EEV blog is my go to before doing something I don't know how to do. Or for just browsing and learning about things I want to do eventually down the experience line. Thanks again for taking the time and writing out this post


Sent from my iPhone using Tapatalk
 
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Offline Brumby

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #9 on: September 16, 2017, 01:17:31 am »
While I agree with what Lightages has said 100%, it is only something that we can try to point out to members and hope some of it is taken on board.

I try to bring things to the discussion that relate to the original question and the skills level of the person who asked it.  Sometimes this is difficult when the person hasn't outlined any background and you have to infer the skill level from the nature of the question.

The other thing is that teaching - which is what we are attempting to do - is not an automatic skill.  There are some people who can perform a particular task blindfolded with one arm tied behind their back - but cannot teach someone else how to do it in a million years.  We have members here with decades of experience who might want to impart a bucketful of knowledge to a person who can only absorb a cupful at this stage in their development.  Knowing which pieces to present and which to hold back (for the time being) is something that not everyone can manage effectively.  This is not a criticism - it's just a fact of life.

As much as we can exhort members here to keep the beginner in mind - and I wholeheartedly support this - the reality is not going to be ideal.

So, to the beginners who read this, please accept our apologies if we get off track in responding to your inquiries - and please forgive us if we go off the deep end about any safety related issues.  We know some things are deadly and don't want you to make that single mistake which could take your life.

... and no, I am not being melodramatic.

Sometimes, there are no simple Yes/No answers.  There can be several factors that may need to be considered to determine the suitability or not of a particular approach.  A case in point is the (current at the time of writing) thread about isolation transformers.  I will not get into the details of that, but suffice to say there have been a number of contributions to that discussion - and that there does not seem to be any consensus.  Each contribution has valid points - but they don't seem to give a straight Yes/No answer.

The reason for this is that there is no absolute Yes/No answer.  There are a number of variables that will affect such a decision - and sometimes they can get too complicated for a beginner to follow.  However - for someone to acquire the knowledge necessary, they will need to understand not only what a particular member has stated, but how all the opinions fit together - even the ones that seem contradictory.

This is a tall order for many, not just beginners, but it is one that needs to be conquered if they are to gain understanding.  Until that happens, confusion and uncertainty will reign supreme.

We don't set out to do this deliberately - it's just how it is with a diverse group of people - but if we can improve, then everyone will benefit.
 

Offline LightagesTopic starter

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #10 on: September 16, 2017, 04:57:07 am »
One last thing for now. Stop calling beginners NOOBS. It is an insult to some and makes them shut down or leave.
Starting to overreach now. Not everyone uses NOOB as a disrespectful moniker for beginners. But, I agree it is mostly disrespectful.

So I said that it is an insult to SOME, and that isn't just what you said? I didn't say that everyone uses it as an insult but because it has that general connotation that SOME could take it that way.
 

Offline Assafl

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #11 on: September 16, 2017, 05:20:22 am »
Sorry about using a term that implies disrespect. It was not the intent.

I have a perfect DMM for a beginner. Not only is is Cat 3 to 600v or so, it prevents a user from plugging the leads incorrectly by shuttering the incorrect receptacles. Furthermore and more useful, it prevents one from moving the switch - say to voltage - if the leads are plugged in the current receptacles.

Obviously it is the Gossen. Should be used by every beginner. Mine is the Energy one that goes new for a cool K (I have the previous version I spent a 1/3 of that).

Can I recommend it to a beginner? Technically and safety minded? Absolutely. Perhaps if they are rich.

But it is mostly nonesense to recommend it to a beginner. It is way out of line to recommend it to someone on a beginners budget.

BTW - speaking cat ratings - I've only ever heard of electricians being hurt by DMMs. Never heard of hobbyists dying for using a multimeter. Not in the 2000's and not in the 90's, 80's or the glory days of electronics as a hobby - 70's and 60's. When kids would take the triode to the pharmacy to tests it at 200v and nobody cared.

I am not saying it didn't happen just that nobody ever mentioned it. Not popular electronics, not ETI, not elektor, not nuts and volts, not circuit cellar. Not even OSHA.

Usually the ones who die from stuff like this are electricians. The have massive exposre to risk and it takes bit one mistake.
 

Offline LightagesTopic starter

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #12 on: September 16, 2017, 05:27:08 am »
BTW - speaking cat ratings - I've only ever heard of electricians being hurt by DMMs. Never heard of hobbyists dying for using a multimeter. Not in the 2000's and not in the 90's, 80's or the glory days of electronics as a hobby - 70's and 60's. When kids would take the triode to the pharmacy to tests it at 200v and nobody cared.

I am not saying it didn't happen just that nobody ever mentioned it. Not popular electronics, not ETI, not elektor, not nuts and volts, not circuit cellar. Not even OSHA.

See point #6 in my original post.
 

Offline Brumby

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #13 on: September 16, 2017, 05:40:53 am »
I am not saying it didn't happen just that nobody ever mentioned it. Not popular electronics, not ETI, not elektor, not nuts and volts, not circuit cellar. Not even OSHA.

Noe everybody wants to advertise their stupidity - assuming they survive.

In a trade environment, there is always someone who will be interested in such events - whoever is administering the Worker's Compensation Insurance for one.  They will want to get the message out to warn others and hopefully save some lives.

But as Lightages has said - silence does not infer safety or reduced risk.
 

Offline Assafl

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #14 on: September 16, 2017, 07:35:06 am »
I did not die from electric shock. That does not mean mains electricity is safe. I also did not die from a terrorist attack. That does not mean airline security is not important.

Perception of safety and security are important. However:

What I had implied is that safety and security rules are always written in blood. Should a door to a cockpit be allowed to open from the inside or the outside? 9/11 and the Lufthansa crash are end stops to the kind of thought that goes into these discussions.

The IEC and ANSI and others look at the figures. They are not always easy to come by but the statistics are there.

Electricians die on a daily basis. They burst into flames, get consumed by arc flash fires, fall of off transmission towers or scaffolding, get comminuted by electrically powered machinery, get hit by robots or runover by electric trains, even remote lighting strikes while testing something (but that is rare) etc. Just lookup google for "electrician deaths" and you'll get many a gruesome videos (only a small percentage get videotaped). A percentage of that is DMM related (or a DMM was used while something else was happening).

Look for "electronics hobbyist death" - and you'll find that there is very little there. Electronics hobbyists do die - but seemingly for other reasons (look at the demise of Speaker Builder and many of the greats that used to write from heart attack, stroke or cancer).

Looking at electrician statistics DMM hardly show up. Most is touching a live wire that was supposed to have been shut off; and then there are falls from ladders. There is also arc flash much lower on the list. Also there are compounded of people shocked and then falling off a roof. Whichever killed the electrician.

The main reason for the Cat Rating is arc fire. Which is not going to happen at home. You can die trying to get your office receptacle to arc - but it is unlikely to ever sustain. Perhaps a spark or two.

If the IEC, or the insurance companies, or governments safety regulators had any perception that hobbyists were dropping like flies from DMMs exploding, IEC standard 61010-1 would be a requirement. Just like GFCI on bathtub hair dryers and thermal fuses on space heaters. And the sticker that says "carbon monoxide poisoning will kill you". It costs nearly nothing to get self compliance to the standard, and were it a requirement everything from China would be compliant.

But it isn't - mainly because hobbyists are probably doing fine (and that is probably why we don't get the periodic headlines of "Jack the teenage technology hobbyist" who died while trying to fix an SMPS with the threat of a lawsuit against Radio Shack).

Lucky for us since we all played with non-cat rated stuff in the 70's and 80's. Including Fluke. 

At a hobbyist level reading the standard, or the Fluke marketing departments rewriting of the standard or Joe's tests of Multimeter claims for self compliance with the IEC standard - it makes for excellent reading as it highlights the difference between voltage, current and energy. Most people on Quora seem to think voltage, or current as being dangerous, while it was always Joules that did damage.

I agree though, that those who play with fire and say "I survive" are not good. I still can't watch the Tesla coil crowd touching their HF coils. Freaks me out.
 
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Offline vk6zgo

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #15 on: September 16, 2017, 07:40:59 am »
BTW - speaking cat ratings - I've only ever heard of electricians being hurt by DMMs. Never heard of hobbyists dying for using a multimeter. Not in the 2000's and not in the 90's, 80's or the glory days of electronics as a hobby - 70's and 60's. When kids would take the triode to the pharmacy to tests it at 200v and nobody cared.

I am not saying it didn't happen just that nobody ever mentioned it. Not popular electronics, not ETI, not elektor, not nuts and volts, not circuit cellar. Not even OSHA.

See point #6in my original post.

Many of the old style analog VOMs were extremely well engineered, with good insulation & massive clearances between  the "hot" bits & not only the operator, but also the vulnerable "guts" of the instrument.

AVOs & the like were not really "handheld" instruments, & usually were placed on a bench, the floor or other stable surface.
With the big scales you didn't hover over them, so were further separated from any "big bang".

Smaller, "hobbyist" grade instruments were not as well made, &  could have been disastrous, but,as Assafi said, the reports of people having meters explode are striking by their absence.

As VOMs were not as easy to use as DMMs, people spent time learning how to use them,
many times with the help of a mentor, who would indoctrinate them with the rule "Check that the meter is on the correct range before measuring".

Every time you used the meter, you had to set the,correct range, so it was self- reinforcing.
The early DMMs did not have auto ranging, so the same rule was easy to apply.

Another point is that meters were expensive, & you were unlikely to own one until you had learnt some basics.
The vast majority were used by Techs, Electricians, etc, as part of their job.

I was around in this period, so I have firsthand experience of how things were done, unlike the younger fry on this forum, to whom such things are as remote as the Punic Wars.
 
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Offline IanMacdonald

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #16 on: September 16, 2017, 07:44:24 am »
"I own an Energy Gossen. It is a nice meter and it works reasonably well. Can I recommend it to a NOOB? Yup (it even shutters the inputs so a NOOB can't make a mistake). But would someone (even a hobbyist) to buy a 1k$ DMM? Hell no. "

Is there even any point in this, since it doesn't prevent the meter being left on a current range with the leads in the current sockets, and a voltage applied? I could imagine it also causes hassle when changing range as the switch and leads must have to be changed in a specific order.  |O

The main safety requirement for beginners is a fused 10A range. This can be a standard glass fuse, nothing exotic. If this range is not fused, there is a real risk of the test leads going on fiire and causing burns if put across a car battery or LiPo.  :bullshit: :'(  Therefore I would suggest that spending a little more than the bargain basement prices is worthwhile for this feature. Spending a fortune on a meter rated for high power electrics work is not worthwhile.

The only place the electrician's grade DMM would really be needed in a domestic setting is if testing at the supply 'tails' where the fusing may be 100A or more, and a beginner shouldn't take this sort of work on until they've gained some experience anyway. .
 

Offline Assafl

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #17 on: September 16, 2017, 08:09:56 am »
"I own an Energy Gossen. It is a nice meter and it works reasonably well. Can I recommend it to a NOOB? Yup (it even shutters the inputs so a NOOB can't make a mistake). But would someone (even a hobbyist) to buy a 1k$ DMM? Hell no. "

Is there even any point in this, since it doesn't prevent the meter being left on a current range with the leads in the current sockets, and a voltage applied? I could imagine it also causes hassle when changing range as the switch and leads must have to be changed in a specific order.  |O

The main safety requirement for beginners is a fused 10A range. This can be a standard glass fuse, nothing exotic. If this range is not fused, there is a real risk of the test leads going on fiire and causing burns if put across a car battery or LiPo.  :bullshit: :'(  Therefore I would suggest that spending a little more than the bargain basement prices is worthwhile for this feature. Spending a fortune on a meter rated for high power electrics work is not worthwhile.

The only place the electrician's grade DMM would really be needed in a domestic setting is if testing at the supply 'tails' where the fusing may be 100A or more, and a beginner shouldn't take this sort of work on until they've gained some experience anyway. .

One of the better reasons to opt for a 25A circuit (utility puts a 35A fuse) rather than a 40A circuit. I had to balance the phases for this, though (12,000W induction, 5kW ovens, 2 multi city inverter AC, etc.).

But even then I'd be very surprised if it is able to supply an arc fire. You really need a distribution panel - and at that point all the equipment ceases to be "hobbyist qualified" and get some ugly crap from the likes of Sibille Outillard or other linesmen manufacturers.

Edit: this is one of the only videos I know of where a multimeter caused a death. Obviously, while a Cat rated device, it used inappropriately, a 600V meter on a 2300V 1200A circuit.

At residential locations what worries safety engineers is lack of GFCI and (same level of concern) extension cords. People die because of extension cords.

vk6zgo is right, though, one can get an autoranging DMM for 10$ and use it incorrectly. The inexpensive d'Arsonval ones (which were actually pretty expensive) had no protection so you had to know how to use them. Still they do not seem to be frying themselves. 

I actually like the Gossen. It is my goto. I did not really buy it though, for the Cat rating nor the shutters, not the DkD cert. I purchased it for the power and energy metering (which are very useful).
« Last Edit: September 16, 2017, 09:31:14 am by Assafl »
 

Offline tpowell1830

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #18 on: September 16, 2017, 09:21:24 am »
IMHO, I think the biggest problem is concern for the safety and how to convey that concern to beginners who throw their enigmatic questions at the forum with non-technical terms, which usually shows their inexperience from the terminology or lack of terminology used in the formulation of the beginner's questions.

However, these days with some meter manufacturers building and selling meters who put the EU or UL or CATIII labels on their product has little or no meaning because those safety agencies have not seen or touched those devices, let alone tested for safety. Bottom line, you can't trust manufacturers labels much anymore. There was a time that these things had a much higher meaning, but with some manufacturers, and I don't just mean Chinese manufacturers, simply lie or misrepresent the level of safety testing done on their equipment. Like I said, anyone with a labelmaker can put a CATIII label on their product. Safety in trying to tell the beginner that CATIII is a better choice for meter is almost lost nowadays. Care should always be taken when measuring any electrical measurements with electrical measuring equipment. This brings me to my next point.

So, for beginners, my advice to you, before you take up this electronics/electrical hobby, is to take some courses on the basics of electrical/electronics and have some understanding of all the nuances involved in YOUR safety. Learn some of the terminolgy as best that you can so that you can ask better questions. After taking some basic electrical/electronic courses, PLEASE, take some safety course specifically dealing with electrical safety and understanding what the labels on electrical test equipment means and why you should pay attention to them. Experience under the tutilage of a mentor is very helpful if possible, but I certainly understand turning to forums like this to get your answers if you are not fortunate enough to have such a mentor. I realize that being a beginner as a hobbyist in this field seems like overkill to have to do all that I mention above, but, it is very necessary to understand the safety aspects because a mistake could injure or cripple you for life or even worse, end your life. This is a disciplined hobby/profession, and as such, one should take a disciplined approach before endeavoring to start.

Asking professionals what they recommend for test equipment is like asking a conoiseur of coffee to recommend a specific coffee. It is all a matter of what each persons experience is with equipment and personal knowledge of situations involving mishaps with said equipment. IT WILL VARY.

OK, 'nuff said from the peanuts gallery, take it for what it is worth: lip service.
« Last Edit: September 16, 2017, 09:24:27 am by tpowell1830 »
PEACE===>T
 

Offline brucehoult

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #19 on: September 16, 2017, 12:07:18 pm »
Just love how this thread has been hijacked by people arguing about multimeters suitable for high voltage/high current. IN a thread on inappropriate and confusing messages for beginners.

That's like ... rain on your wedding day.

Maybe I'm wrong, but I'd have thought the vast majority of beginners who turn up in an electronics (NOT electrician's) forum are interested in working with things at 12V, 5V or lower. Transistors, op amps, TTL/CMOS, microprocessors etc.
 

Offline b_force

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #20 on: September 16, 2017, 02:25:30 pm »
Just love how this thread has been hijacked by people arguing about multimeters suitable for high voltage/high current. IN a thread on inappropriate and confusing messages for beginners.

That's like ... rain on your wedding day.

Maybe I'm wrong, but I'd have thought the vast majority of beginners who turn up in an electronics (NOT electrician's) forum are interested in working with things at 12V, 5V or lower. Transistors, op amps, TTL/CMOS, microprocessors etc.
Reading your first post, safety is CLEARLY a matter of difference in opinion and probably culture as well.
I have traveled and worked all around the world, and safety is one big grey area.
ESPECIALLY in electronics!
Some things are being considered safe and even part of regulations in one country, they are totally a no go in other countries.
I had many face-palm moments  :palm:, but also many moments like, why the hell don't other countries do it this way  :clap:

From this experience I think the only conclusion can be; Just use your brains and think about the context!
Context is key word here, because comparing situations is impossible a lot of times.
And if you don't feel comfortable doing things, just simply don't do them.
Quote
What are the chances that it will happen to you? Who knows? Do you really want to find out?
Unfortunately it DOES work that way. Regulations and safety rules are directly connected about the changes of getting an accident.
If you go back into history, (awful) things first need to happen to a certain amount before regulations and laws are being made.
In fact, that's a basic rule of life, otherwise you can better hide yourself in a cave (and even THERE are changes to get yourself killed!  ;D)

The point is that some people/cultures see or explain these changes on a different way.
For example, some countries really put a lot of energy in the awareness, while others are much more strict with really prohibiting things (without explaining why).
I personally very strongly believe in creating awareness, because in the long run your investments will pay off much better because the world is not a black and white environment (very far from it!).
So actually, by definition you can't make rules/regulations that will keep everyone happy.
For that reason I don't believe in strict rules at all, simply because people don't use their brains anymore.

Anyway, this was just an example (for starters, but basically for everyone) how difference in approach can lead to heavy discussions, and why.
The reason why is obviously that no-one likes to get injured or killed. Only the approach to accomplish it, is very different.

My best advice to everyone (not only starters) is try to move yourself in the other person.
Try to see things from his perspective and follow his arguments.
Mostly, don't go nit-picking on details ("yes, but in this very specific situation I had this and that experience"), but try to focus on the global meaning of it.
And IF you have an experience that is very different, phrase it as a question.
example: "I get what you're saying, but what is the explanation why I had another experience?"

Another tip also for everyone (but mostly the oldies).
Just please leave your principles and pride behind.
Everyone makes mistakes, even if you're already "30 years in the field", there is absolutely nothing wrong with making them and admitting them.
Although I am aware that some cultures/countries really have a 'blaming culture'.
It's not about who to blame, it's about finding a solution.

Also I see this so often: someone ask a question -> answer: here you have a big (difficult) book, go read it yourself.
Absolutely useless! That's not an answer and that's not helping! :--
If you don't have the patience to explain things, just don't.
(my experience is that in a lot of cases these people don't really understand it themselves but are to proud to admit it)

Last bit; we are here to help each and share things with each other.
It's NOT a competition were the person with the most amount knowledge, or best answers wins.
I know there are mostly men here, but sometimes the amount of testosterone can be a little lower so to speak.

the first post already contained a lot of good points.
To add one more for starters (but again, basically for everyone).
Dumb questions don't exist, so don't be shy to ask, ask, ask and even ask more.
In fact, it was Einsteins motto; you can never ask to many questions.
« Last Edit: September 16, 2017, 02:28:32 pm by b_force »
 

Online rstofer

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #21 on: September 16, 2017, 02:26:44 pm »
This is getting absurd.

What should I do with my Simpson 260s?  Crush them under the tires of my battery car?
And my old Heathkit V-O-M that I built decades ago?  Same thing?  Clearly no listing or rating on a kit!

What if my great-great-great-grandson happens to inherit them?

The first 260 I picked up off my shelf just now has no UL Listing, no CAT rating and uses a glass fuse.  Horrors!  Yet I know for a fact that these are used in nuclear power plants because mine came from a plant operator's training center.

Furthermore, the 260 is still the tool of choice for electrical work in substations and related switchgear.  Until I retired 13 years ago, every service tech I knew had a 260, and a van full of other test gear.  They may have also had something from the Fluke lineup but the 260 was ubiquitous.  Note that most switchgear will have a potential transformer stepping the 12kV (or whatever) down to 120V for instrumentation.  Regardless of scaling, the volt meter movements were usually rated for 120V.  The current instrumentation is usually 0-5A. 

Oh, and NEVER open the secondary circuit of a current transformer. <= free hint!

Triplett makes a nice meter as well.  I actually prefer the recessed knob of the Triplett 630 and, for a compact meter, the 310 is just right.  Add on a current clamp and it's a handy tool!

As I posted earlier, it is possible to mess up mightily with any kind of test gear.  So THINK!
"How is what I'm about to do going to hurt me?"  "How am I going to prevent that?"


 

Offline Assafl

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #22 on: September 16, 2017, 03:55:03 pm »
I would assume the reason the Simpson was so well liked was that it prevented phantom readings. Another thing a beginner would not find worthwhile knowing.

It is as if there is an assumption that beginners run naked in the streets yelling Eureka! Eureka! Find the nearest distribution box, hack it open, remove the Lexan Danger! Shield, set the DMM on mV range, stuff the leads into the 10A jack and probe with abandonment.

I was never like that. Maybe others were.

There is a far more likely bang when they probe their SMPS with their new Rigol scope. Because we were busy talking about Cats.
 

Offline SeanB

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #23 on: September 16, 2017, 04:28:20 pm »
Many current transformers now come with open circuit protection, often just by incorporating a very beefy MOV inside the encapsulation to dissipate the open circuit power safely. They can generate incredibly high voltage open circuit at full input current, and generally enough to arc over as well. Same with voltage transformers, they also generate a current output.
 

Offline LightagesTopic starter

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Re: Beginners and beginner questions, why the disparity in answers?
« Reply #24 on: September 16, 2017, 06:16:43 pm »
The matter of safety is not only the safety of the user. Of course that is an important aspct but there are others too. People are doing exactly what I said would happen in a beginner's post. Here we go again with unending arguments over what level of safety YOU care about. I don't give a flying #$%^what individuals think they can or cannot get away with. Stop pushing agendas. That is the point of my OP. When a beginner asks, we should not tell him to buy any piece of crap and forget safety, he must learn himself or know before he starts. This is where this always goes.

Getting equipment that is marked correctly for its rating and is tested to meet the rating is an indication of quality too. If a manufacturer is willing to falsely mark a meter, for example, with CATIII 600V and it is not real, what else are they lying about? What other shortcuts have they taken in the manufacture of the meter? If we, as the experienced, don't speak up about these problems then how is the beginner supposed to find out, by accident?

There is also the aspect of protection of investment. Good luck with the DM830 ebay $5 meter if you accidentally connect the leads to a car battery with the leads still in the unfused Amp jacks. Oh well, its just $5 and maybe a small fire in your car. What about when it reads 5V instead of the 15V that are really there because of a crappy range selector and you connect that 15V to your carefully hand crafted circuit and you kill your circuit/DUT?

Like I said, the cheapest crap gear needs the most experience to use. You need experience to understand the potential problems and to know that the junk meter you have in your hand cannot be trusted to the extent that something with real markings and good construction can be trusted. That is why it is best to recommend equipment to beginners that will not cause them problems and give the reliable basics that will then help them learn instead of get pissed off with failures from shit equipment.

There is more than just one side to recommending equipment, stop fixating on safety or not safety. It is important but consider the whole picture.
« Last Edit: September 16, 2017, 06:41:40 pm by Lightages »
 


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