How Can You Convert AC Amperage to Voltage?

[KelSolarr]

Does anyone know of a way to convert AC amperage to voltage? I need a way to do this so I can use normal electronical components instead of having to design my own.

 

[Averagesupernova]

By the title of this thread I can tell you need to learn a bit about electricity. Current flowing through a resistor develops a voltage across the resistor. One of the first things taught in electronics. Not sure what you mean by 'designing your own components'. Tell us what your project is please.

 

[Topher925]

I know of a lot of ways. You said nothing about your application so I'm going to assume you want a current sense amplifier.

http://www.analog.com/en/amplifiers-and-comparators/current-sense-amplifiers/products/index.html

 

[cabraham]

Does anyone know of a way to convert AC amperage to voltage? I need a way to do this so I can use normal electronical components instead of having to design my own.

Ohmage.

Claude

 

[hemant03]

You could see a current to voltage converter op-amp design

 

[cabraham]

Also, a Hall effect current sensor could be used. Allegro has many of them.

Claude

 

[KelSolarr]

I guess what I mean by designing my own components is that i could just buy what i need instead of hunting to the wastes of Egypt and back to find one that uses a amp based power source.

I know that almost every type of component uses about the same volt and amp per componenet "class" but when going to a different "class" it only really affects voltage with minimal if any amp change. I also believe the reason for that is that amp level is the only range for best possible human safety.

I'm not really worried about human safety because I plan on grounding all metal that can be touched (within reason).

 

[Averagesupernova]

I'm not really worried about human safety because I plan on grounding all metal that can be touched (within reason).

See my previous post.

 

[KelSolarr]

So am I not correct in assuming it's only harder not near impossible to find components that run off of higher amps then volts?

 

[vk6kro]

You vanished a couple of weeks ago.

While you are on line please explain what you are trying to do.


Re: converting amperage to voltage
So am I not correct in assuming it's only harder not near impossible to find components that run off of higher amps then volts?

Do you mean low resistance circuitry? Or what?
You can have low voltage circuits that use more current but we need to know exactly what you are talking about.

 

[KelSolarr]

Ok. I guess I've reached the point to where I have to give up a few details. I'm working on a generator. The problem is it provides higher amps and lower volts. I'm also planning on using this for mainly five different types of components, one being an electric motor. I'm not wanting to have the amp-volt converter be built into the generator so I can pull straight to the motor. I am willing to let the efficiency drop to the other components because they are not so performance important. Does that help?

 

[vk6kro]

This is not a time to be secretive.

You still haven't said what you are trying to do or what sort of generator it is. What is driving it?

It is low voltage (but how low and is it AC or DC?) and it can deliver a lot of current (but how much current?).

BUT what do you actually want to do with it? You want to run 5 different sorts of components off it, but what are they and what is their total function?

You will just get a lot of irrelevant replies or no replies if you don't explain in detail what you are trying to do.

 

[KelSolarr]

I already stated that one component was an electric motor. the other 4 run off typical ac house power (110-220v). I'm not finished with the generator but it provides an unknown amount of AC current.(reson: I am still in the designing stages. I haven't been able to build it yet.)

And I'm sorry that I'm being secretive but I've been hurt in the past by others stealing my ideas.

 

[berkeman]

Ok. I guess I've reached the point to where I have to give up a few details. I'm working on a generator. The problem is it provides higher amps and lower volts. I'm also planning on using this for mainly five different types of components, one being an electric motor. I'm not wanting to have the amp-volt converter be built into the generator so I can pull straight to the motor. I am willing to let the efficiency drop to the other components because they are not so performance important. Does that help?

It would help if you learned a bit more about electricity. Then you could answer your own questions like this, or at least could ask the questions using standard terminology. Right now, we are having to guess and try to parse what you are asking, so the process is much more drawn out and painful than it needs to be.

Your statement "it provides higher amps and lower volts" makes no sense. Higher and lower with respect to what? Do you mean it does not produce AC Mains voltages, and that's what you want to convert the output to? Is the output DC or AC? If AC, just use a transformer to step up the voltage to 110Vrms. If DC, use an inverter or a DC motor to AC generator converter.

 

[Averagesupernova]

I smell a perpetual motion machine here. When someone new comes to this forum, has some plan for some machine that they do not want to reveal too much information on, and doesn't seem to have a firm grasp on electricity it usually ends up as an attempt at an overunity device. So tell us KelSolarr, whaddaya got?

 

[KelSolarr]

Well I guess someone around here has common sense. As for what do I have, and learning about electronics, read my blog.

https://www.physicsforums.com/blog.php?b=1012

Again I appologize to anyone who can't or won't help me because of this. I "have a grasp" on electroinics, it's just varying on what part of it. And I do keep up on current or new technologies (like those trying to use graphine for near atom-transistors to use in computers that should speed them up by x10). I grasp theories and theoretical equations really well. I believe that's part of my problem with this. And other basic questions I have.

And maybe I should try refrazing my initial question. I have AC "generator" providing very high amperage. How do I get it limited or stabilized so I can use home powered electronics off of this generator?

I use "generator" because I do already know that you cannot "create" energy, just change the form. Like wind powered generators goes from wind energy and converts it to electrical energy.

 

[KelSolarr]

I also have a side question. Am I correct in remembering that Amperage is the frequency (lenght) of the wave and Voltage is the size (height) of the wave?

 

[berkeman]

And maybe I should try refrazing my initial question. I have AC "generator" providing very high amperage. How do I get it limited or stabilized so I can use home powered electronics off of this generator?

I use "generator" because I do already know that you cannot "create" energy, just change the form. Like wind powered generators goes from wind energy and converts it to electrical energy.

So your generator produces power at a low AC voltage, but can supply lots of current. Fine. Is the output voltage reasonably constant? If so, then a transformer can be used to step the voltage up to AC Mains levels.

If the output of your generator is not a constant AC voltage, then it will take a more complicated circuit. Probably the most efficient would be to full-wave rectify the low AC output voltage, and follow that with an AC inverter circuit.

You need to be careful working with AC Mains voltages (110Vrms in the US), because of the shock and fire hazards. Please learn a lot more about electrical safety before messing with AC Mains voltges. Please also be aware that you cannot run off of street power and local power at the same time (generally). You should google "cogeneration of electricity" for more info, and check with your local electric utility company to find out what their policies are for cogeneration.


EDIT -- BTW, what frequency is the AC output of your generator? Is is constant? If it is anything other than a constant 60Hz (or 50Hz, whatever your local utility uses and what your house appliances are expecting), then you will need to go with the rectification and inverter power conversion.

 

[Redbelly98]

And maybe I should try refrazing my initial question. I have AC "generator" providing very high amperage. How do I get it limited or stabilized so I can use home powered electronics off of this generator?

I'm working on a generator. The problem is it provides higher amps and lower volts.

If the voltage is too low to power normal household electronics, a simple step-up transformer is what you need. I'm assuming the frequency is reasonably close to mains frequency -- if not, then that is a problem.

Have you actually built this device, or is it in the design phase?

 

[vk6kro]

I also have a side question. Am I correct in remembering that Amperage is the frequency (lenght) of the wave and Voltage is the size (height) of the wave?

Voltage is the height of the AC signal. If you were looking at a sinewave, you might measure the difference in "height" between the top and the bottom of the sinewave. This is called the "peak to peak voltage".

Frequency is the number of sinewaves that happen each second.

Amperage is NOT the same as frequency. It is an old term that refers to current capability.
Current is a flow of electrons that flow when a voltage is placed across a resistor. The unit of current is the AMP.

So, a few examples.
Keys on a piano correspond to higher frequencies as you move to the right of the keyboard. That is they produce more oscillations each second.

A flashlight bulb would get a voltage of 3 volts and it would draw a current of about 0.3 amps if it had two batteries in it.
A headlamp bulb in a car would get 12 volts supplied to it and it might draw 6 amps of current. In these cases the frequency would be zero because the voltage is constant DC.

Did you know you can send Personal Mail on this Forum if you want to keep something more secret? Just click on a nickname (like VK6KRO) and look for the private message part.

Nobody can design something for you unless you can tell them what voltage you have, how much current it can deliver into a suitable load and what voltage you want and what load it has to supply.
If you have been confusing amperage with frequency, maybe you know the frequency of your generator?

 

[Redbelly98]

I also have a side question. Am I correct in remembering that Amperage is the frequency (lenght) of the wave and Voltage is the size (height) of the wave?

Somehow I missed this earlier. To be honest, I think many in this forum are tempted to stop responding after reading this question.

Whatever it is you are doing, all electronics pretty much starts with an understanding of what current and voltage are. They are the two most basic concepts in electronics, everything else is predicated on an understanding of what they are. In particular, your ability to design a generator requires that you understand them.

With that, I will recommend that you get a book on electronic circuits, read the opening chapters, and come back here with questions.

The "gold standard" is Horowitz and Hill's The Art Of Electronics, which may run around $100.00. If you don't want to spend that much, you could browse around at a bookstore for something cheaper.

Good luck.

EDIT / p.s.
To put it simply: current (what you call amperage) is the flow of charge in a circuit. Voltage can be thought of as the force that moves charge through a circuit ... though strictly speaking it is an energy potential per unit charge, and not a force.

 

[KelSolarr]

So far. Only two (maybe three but we'll see on that.) of you have actually listened to me. And I will answer some of these questions but I do believe I have gotten many answers. And yes. I do believe many will stop responding. If anyone actually read my blog, those still reading already know that I am expecting that. I only want help from those that are willing to help. I don't have money to just go drop it on books to educate myself and my side question was because that's how I was taught in my electronics class or so I remember. I apologize, when I wrote my blog I was distracted and I forgot to mention that.

As for the technical questions. yes it is still in design phase. More because I need to figure out what the motor(s) are going to use. The motors are the only things not running on home based power. I can very easily change the frequency of the generator. So I guess I have my theories/calculations backwards. All of which has been answered by the one of the only people actually listening or understanding me. Meaning I only have one question left that I have already asked that has not been answered. Should I not be hare? Am I not somewhere where anyone will help me? Thats the only reason I joined was because this looked to be a place where people help other people with their problems.

 

[Averagesupernova]

Look KelSolarr, I don't know how to tactfully put this, but I'll try. The reason that you won't get an answer from here that you are looking for isn't because you won't tell us what you are doing. It is because quite simply you don't understand electricity. Getting frequency and current confused is like confusing the color of a pail and the amount of water it will hold. They are both properties of the pail but neither one really has anything to do with the other. It is VERY understandable that anyone without any education concerning electricity wouldn't know current from frequency. There is nothing wrong with that. But in this case, you come in here claiming that you are prepared to make your own components but prefer not to, which implies you do know something about electricity and then confuse current and frequency. NO ONE will take you seriously anymore.
-
Now I will try to answer the question that is in the title of this thread in the only way I see that the question makes sense in the first place: There is no way to convert amperage to voltage and vice-versa. However, if you have a voltage source that is lower than you want but able to supply way more current than you need, as others have pointed out you would use a transformer to step the voltage up at the expense of reducing available current. Ignoring inefficiencies of the transformer, if you use a transformer that is stepping up the voltage by a factor of 10 you will reduce the available current by a factor of ten. In other words, watts in = watts out. No gain here, only loss due to the inefficiency of the transformer.
-
I'm sure this won't help you with your project but I'm hoping that it does show you that you cannot make shortcuts and carelessly skip all the book learning. Don't have the money to buy books? Ever hear of a library?

 

[Redbelly98]

I don't have money to just go drop it on books to educate myself

I just discovered that the Horowitz and Hill book is online, i.e. free. "Skip ahead" to page 1 at this link:
http://books.google.com/books?id=bk...a=X&oi=book_result&ct=result&resnum=9#PPP1,M1

...this looked to be a place where people help other people with their problems.

Sorry if we sound unduly harsh. But the impression is that where you need help, where your problem is, is with understanding the basic principles first. Electronics can be dangerous to work with, and you seem to be talking about dangerously high currents and voltages.

I know you have your reasons for keeping specifics out of the discussion, but that has made it difficult and time consuming to discover that what you need is probably a step-up transformer -- again (and I cannot stress this enough) after you have learned and understand the basic principles.

 

[KelSolarr]

And I take it that none of you are willing to help me learn the basics? If that is the case then I shall give my thanks and bow out peacefully.

 

[Averagesupernova]

And I take it that none of you are willing to help me learn the basics? If that is the case then I shall give my thanks and bow out peacefully.

Whoa! No one has said that. It takes a lot 'nads to ask for help learning the basics after the direction this thread has taken. If you are serious about this then by all means you will be helped. So where are we? What do you need to know? I think the basics of transformer action has been covered.

 

[RonL]

And I take it that none of you are willing to help me learn the basics? If that is the case then I shall give my thanks and bow out peacefully.

Thank you for saying a little about yourself in the profile section, I see you work as a call in technician which tells me you are somewhat skilled in the art of communicating with others. There is all the information you need, here and on wikipedia, and the people are plenty willing to help.

It sounds a little like you have an idea along the lines of a homopolar generator, and if you do, you need a stepup transformer. Study through the electrical engineering section, do some searches in wikipedia, then try to reword your questions in another thread if nessessary, but above all be patient and try to figure out why everyone is having a hard time grasping your questions.

Ron

 

[berkeman]

I just discovered that the Horowitz and Hill book is online, i.e. free. "Skip ahead" to page 1 at this link:
http://books.google.com/books?id=bk...a=X&oi=book_result&ct=result&resnum=9#PPP1,M1

Cool find, RB. It looks like the whole book isn't available, but probably a significant portion may be. Especially the basic stuff in the first few chapters, which is what the OP could use the most here.

How are book previews limited?

Many of the books you can preview on Google Books are still in copyright, and are displayed with the permission of publishers and authors. You can browse these "limited preview" titles just as you would in a bookstore, but you won't be able to see more pages than the copyright holder has made available.

When you've accessed the maximum number of pages allowed for a book, any remaining pages will be omitted from your preview. You can order full copies of any book using the "Buy this book" links to the right of the preview page.

 

[Redbelly98]

More on the Horowitz and Hill book: amazon.com has used copies for about $50 including shipping...
https://www.amazon.com/gp/product/0521370957/?tag=pfamazon01-20

... and you can look at the table of contents + 1st 5 or so pages also:


Note to OP: what we mainly do at Physics Forums is to either "fill in the gaps" of what people already know, or explain the beginning basics to people who know very little about a particular subject or technology.

That being said, to take somebody from the beginning basics to where that person can design and build a real working generator would require more time than any single person is generally willing to spend. This is what most people take years of study to learn to do. It is also more than can be done in a single thread topic at Physics Forums.

So feel free to keep posting questions here, just be willing to accept that it can take a while to learn everything. It's good that you have had an electronics course in the past, it does sound like reviewing the basics would be beneficial for you. If it's a matter of refamiliarizing yourself with things that have been forgotten, rather that starting totally from scratch, all the better.

Regards,

Mark

 

[KelSolarr]

It's not that I'm having trouble understanding why everyone is having trouble with my questions. It's more that I felt like everyone was yelling at me for not knowing the basics. With that I was feeling like no one was wanting to help. I apologize. And no that's not the type of generator I have in mind. I do want to thank all of you for your ideas and tips. As for my electronic questions I do have my answers. Thank you.

 

[Relay]

Intresting! What is better a learned man not seaking the truth or an untrained man yearning for the truth. If I had 1000 scientist not looking for free energy and a 1000 crackpots looking for free energy, who will find free energy first? The first time I ran into this problem was in school when a few of my classmate stated, "If that was a good idea somebody else would have thought of it." They generally didn't do well. The rest of us constantly reinvented the wheel.
In the last hundred years we haven't found many new secrets of nature. We certainly embelished the ones discovered. There is so much to know in the universe and our most educated are handicaped by their education, beliefs, and don't forget the governments of the world. For those reasons people like KelSolarr are needed. The person who doesn't have the financial support or proper resources can still stumble across a discovery. If these crackpots of science do nothing more than be laughed at by the establishment they have still made an impact. They have brought the idea for something new, the need to discover the next great secret of nature.

A quick lesson on electricity;
Voltage is like the pressure of water in a hose and is measured in volts. Current is like the size of the hose and is measured in amps. Together they are power; measured in watts. A resistor is like a flow control in the hose measured in ohms. The smaller the hole the less water will flow and this is like a large resistance. A capacitor is like an accumulator which will try to maintain the pressure in the system and is measured in farads. An inductor is like a hydraulic motor connected to a large flywheel. It will prevent large flow at the onset and gradually allow greater flow. Once the flow is stopped the flywheel will force the motor to maintain the flow. Inductance is measured in henries. Power is voltage times current or voltage squared divided by the resistance, or the current squared times the resistance.
Most important of all is that only 100mA of current across a person's heart will kill them. 25000 volts will jump a 1 inch air gap. When working with high voltage have one hand in your pocket.

 

[vk6kro]

I remember this one. Quite a few people tried to help, but the poster was unable and unwilling to explain exactly what he wanted.
Eventually he said he had his answers.

A quick lesson on electricity;
Voltage is like the pressure of water in a hose and is measured in volts. Current is like the size of the hose and is measured in amps.

I try to avoid plumbing comparisons as they cause more confusion than they are worth.
The current in an electrical circuit is not comparable with the size of a hose in a plumbing circuit. If anything, it is comparable with the rate of flow of water in the hose.

 

[Relay]

I stated my "...quick lesson on electricity" for the benefits of those not very learned on electricity. There is always the danger the analogy will be taken too far. For that reason many people avoid plumbing comparisons. I've found them most effective in explaining to a home owner why he cannot wire his stove with 14 gauge copper wire.

 

[Redbelly98]

I think the plumbing analogy is useful for explaining water flow to electricians, electrical engineers, and scientists.

 

[vk6kro]

There are problems with using water analogies.

If you say current is like water flowing in a hose, you come to grief when you say the current has to return to the other side of the battery. Water in a hose ends up on the garden so why would it go back to the reservoir?

If you say that voltage is like the "head" of water, or the pressure due to the height of the water source above ground, then how do you then explain that the only voltage that matters is the voltage between the terminals of the voltage source?

You probably could pump water around in a circle to give a true analogy of what an electric circuit does, but it isn't a situation most people are familiar with.

 

[Averagesupernova]

ALL analogies have flaws. ALL analogies make more sense if this is kept in mind. It's somewhat up to who is doing the explaining using the analogies to determine if it fits well enough to use.

 

[russ_watters]

There are problems with using water analogies.

If you say current is like water flowing in a hose, you come to grief when you say the current has to return to the other side of the battery. Water in a hose ends up on the garden so why would it go back to the reservoir?

You probably could pump water around in a circle to give a true analogy of what an electric circuit does, but it isn't a situation most people are familiar with.

Most people don't deal with them much, but I would think they are at least familiar with the concept: You can talk about a closed system such as a chilled water plant. You have the pump working as a battery, then multiple loads in the system.

If you say that voltage is like the "head" of water, or the pressure due to the height of the water source above ground, then how do you then explain that the only voltage that matters is the voltage between the terminals of the voltage source?

I'm not quite following. Though head is used for easy conversion to height, all pumps have a head pressure rise whether there is a rise in height or not. The delta in head across the pump is very analagous to the voltage rise across a battery.

No, of course it isn't perfect but if care is taken in the construction of the analogy it can be quite useful.

 

[vk6kro]

A pump is only a good analogy for voltage in a closed loop. If the pump takes water out of a lake and squirts it in the air, where is the analogy then?

Analogies are like teaching a kid baby talk. You teach "choo-choo" then you teach "train". The kid learns two things instead of one.

So, we say current is like water flowing, sort of.
Then we say it is a flow of electrons.
Then we say it is conventional current so it flows the other way.
Then we say it isn't even electrons flowing, it is a wave passing through electrons. Individual electrons hardly go anywhere.
Then it is a wave of electrons flowing the other way. Got to have conventional current.

Why not just start off with the real story and cut out the stuff that isn't true?

 

[stewartcs]

A pump is only a good analogy for voltage in a closed loop. If the pump takes water out of a lake and squirts it in the air, where is the analogy then?

The water falls from the air and back into the lake and the pump repeats the cycle.

Why not just start off with the real story and cut out the stuff that isn't true?

Because it is typically easier for most people to build upon concepts they already understand. I'm sure you weren't taught differential equations before basic addition and subtraction right? Imagine how confused you would be if you had not learned those basic concepts first and built upon them to eventually understand differential equations.

CS

 

[sophiecentaur]

The water falls from the air and back into the lake and the pump repeats the cycle.



Because it is typically easier for most people to build upon concepts they already understand. I'm sure you weren't taught differential equations before basic addition and subtraction right? Imagine how confused you would be if you had not learned those basic concepts first and built upon them to eventually understand differential equations.

CS

The only problem with teaching by analogy is that you have to be reeeeealy careful to ensure your pupil realizes that it is an analogy and that extending the analogy beyond what you told them may be very dodgy. It should always be:

"Analogy - Caveat - Caveat - Conclusion / Prediction"

and it seldom is, in fact, taught that way.
The fact that there are so many confused questions from non-cogniscenti about electricity and pressure analogies simply proves my point.

Geez, there are enough problems and misconceptions with actual water flow and pressure to show that the whole thing is pretty fraught. I think that, of the dozen or so Plumbers I have dealt with, not one of them had a 'safe' understanding of pressure so heaven help the Electricians with the same model in their heads.

 

[stewartcs]

Geez, there are enough problems and misconceptions with actual water flow and pressure to show that the whole thing is pretty fraught. I think that, of the dozen or so Plumbers I have dealt with, not one of them had a 'safe' understanding of pressure so heaven help the Electricians with the same model in their heads.

Plumbers (in the US at least) generally don't study fluid mechanics (maybe some basic Plumbers fluid course if any). So I'm not surprised that they don't understand those concepts all that well.

Nevertheless I agree that analogies should be treated as that...a tool for helping to build an understanding of some other concept...hence the name.

CS

 

[sophiecentaur]

I wasn't talking "fluid mechanics". I was talking simple static head concepts and the 'obvious' stuff that occurs in everyday Central Heating systems. It's done (apparently) completely 'by numbers' and there never seems to be any System Analysis when fault finding. That sounds very elitist, I know, but I have had to bite my tongue on a number of occasions and let the guy do the 'wrong thing' first before he got things to work - and all because of some simple misconception about pressure and flow.
Hence my reservations about giving someone a water analogy and expecting them to treat it with due care when applied to Electricity. Believe me, I have seen / had to rectify the results!

 

[stewartcs]

I wasn't talking "fluid mechanics". I was talking simple static head concepts and the 'obvious' stuff that occurs in everyday Central Heating systems. It's done (apparently) completely 'by numbers' and there never seems to be any System Analysis when fault finding. That sounds very elitist, I know, but I have had to bite my tongue on a number of occasions and let the guy do the 'wrong thing' first before he got things to work - and all because of some simple misconception about pressure and flow.
Hence my reservations about giving someone a water analogy and expecting them to treat it with due care when applied to Electricity. Believe me, I have seen / had to rectify the results!

Static head, air flow through ducts, etc. are fluid mechanics concepts. HVAC technicians don't design those things, Mechanical Engineers do. The technician only needs to know enough to troubleshoot and repair them, not design them or do any kind of system analysis. Of course there are some technicians through self-study or other means who can do it but they are the exception to the rule.

I wouldn't give a person the water flow analogy if they were trying designing an electrical system, I'd expect them to be properly trained as an Electrical Engineer. In fact, that seems to be what happens most of the time (especially on the internet forums)...people come here looking to do some type of engineering but aren't trained to do it and ask opinions from anonymous people about how to do it. Naturally, a lot of analogies are used because it doesn't take a lot of effort and the person ends up applying them the wrong way.

The moral of the story is: make sure you know what you're doing by being properly trained.

CS

 

[russ_watters]

A pump is only a good analogy for voltage in a closed loop. If the pump takes water out of a lake and squirts it in the air, where is the analogy then?

Yes, if you use an analogy in a situation where it doesn't work, it doesn't work. So what? That's why you only use an analogy in a situation where it works. It is a strawman to try to criticize an analogy for not working in a way that it isn't used anyway.

Analogies are like teaching a kid baby talk. You teach "choo-choo" then you teach "train". The kid learns two things instead of one.

No, the purpose of an analogy is to use one thing that has already been learned to learn another that hasn't. It is a way to avoid having to start from scratch.

Why not just start off with the real story and cut out the stuff that isn't true?

Because people won't know what the heck you're talking about, it'll take longer to learn and you'll have to work backwards learning a lot of the more basic stuff anyway.

Part of my problem with your method is that when you hit someone with a piece of information far outside their understanding, they don't learn it, they memorize it and sometimes fail to really understand it. By linking similar concepts, you have have less to learn and a wider base on which to put it - two connected facts are easier to learn than two disconnected facts.

 

[russ_watters]

Static head, air flow through ducts, etc. are fluid mechanics concepts. HVAC technicians don't design those things, Mechanical Engineers do. The technician only needs to know enough to troubleshoot and repair them, not design them or do any kind of system analysis. Of course there are some technicians through self-study or other means who can do it but they are the exception to the rule.

Agreed. A technician who'se job it is to solder pipe and start-up a piece of equipment doesn't really need to know anything about thermodynamics or fluid dynamics, so it isn't surprising that many don't.

 

[sophiecentaur]

Agreed. A technician who'se job it is to solder pipe and start-up a piece of equipment doesn't really need to know anything about thermodynamics or fluid dynamics, so it isn't surprising that many don't.

It matters if he's come to your house to troubleshoot a problem with your plumbing system and you are paying him by the hour. That's the level of technician that is sent by the Gas Company or the Emergency Plumbing service and I am just making the point that even the simple concepts of pressure and water getting around the house successfully are actually much more difficult than you / we, as probably well informed and fairly Science - literate will appreciate. A simple air lock due to a horizontal run of pipe is much harder to comprehend than you might think.
So what you may think of as a perfectly straightforward model to use as an electrical analogy may be, in itself, quite problematical BUT, because it appears familiar, it can easily be taken up wrongly.
At least, when you give 'em Ohm's Law, they will realize just what difficulties they're up against.

 

[russ_watters]

It matters if he's come to your house to troubleshoot a problem with your plumbing system and you are paying him by the hour.

No, it really doesn't. He measures the refrigerant pressure and compares the reading to a table. He looks at fans and makes sure they are spinning (and in the right direction!). He looks at error codes on the system board, etc. There is no need for him to know thermodynamics or fluid dynamics.

If on a commercial system, he suspects something out of normal bounds (and he's got a table with the design drawings that tells him what all of the operating parameters designed by an engineer should be), such as too much air pressure at the fan outlet and not enough pressur and can't figure out why, he calls-in an engineer -me - to troubleshoot further.

You'll almost never see an engineer working on a residential system, but maybe you should: there is a reason why most residential systems contain either design and/or installation/operational flaws. But it currently isn't considered important engough in most places to have an engineer on the project. Conversely, you're required by law to have an engineer design a commercial system because the fluid and thermodynamic concepts involved are too important to leave to a technician who'se expertise is based mostly on rules of thumb.

That's the level of technician that is sent by the Gas Company or the Emergency Plumbing service and I am just making the point that even the simple concepts of pressure and water getting around the house successfully are actually much more difficult than you / we, as probably well informed and fairly Science - literate will appreciate.

You're arguing against your own previous point here. You were right when you said none of the plumbers or electricians you've dealt with have a good understanding of these concepts. You're wrong to think they should. Heck, you're now basically arguing that every technician you've ever run across is underqualified for their job!