Author Topic: top 10 uses for Function Generators  (Read 3293 times)

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Online AndyC_772

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Re: top 10 uses for Function Generators
« Reply #25 on: April 26, 2019, 11:09:23 am »
I completely agree, but bear in mind, someone just starting work needs to have a more academic bias if they are to end up a competent engineer after some time in industry.

If they start off with too little academic, theoretical knowledge, and then add pure on-the-job experience, then they'll become technicians - and may have missed the only opportunity to become the best engineers they could have been.


Online Berni

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Re: top 10 uses for Function Generators
« Reply #26 on: April 26, 2019, 11:37:18 am »
I'm not entirely sure how I feel about this kind of project being set as part of an academic course. As some of you may know, I design sensor products for a living; sometimes these are an off-the-shelf component packaged up in a convenient way for the application, other times they're designed from the ground up starting with the underlying physics.

Learning how to google a data sheet, make sense of it and infer what supporting components a sensor will need is something which can be readily done in industry, and it's the sort of thing I'd fully expect to teach a junior engineer on the job. Being able to do it correctly is more about experience than theory, and you really don't need to take up precious course hours decoding some particular vendor's badly documented register set, or trying to solder a QFN without wrecking it. They're practical skills that I can teach someone quite easily.

In an academic course, I'd hope and expect that students will be taught the principles of operation of these sensors. How do they really work? What are the underlying physical processes going on? What factors influence their readings? What are the fundamental, theoretical limits on how well then can work? Why might a given type of sensor be a good choice in application A, but entirely inappropriate in application B? What knowledge and insight can a graduate bring to my company that I can't read for myself off a manufacturer's data sheet?

This was just part of one semester of this subject. The lectures did go into the theory behind how all sorts of sensors work and there was lab work in characterizing and using sensors. But that part mostly followed the usual way of teaching. Tho the lectures did include good amount of experiments shown mid lecture. But what followed was this particular semester that has taken this different approach.

I'm not saying that all lab work is supposed to be done this way, but at least some of it should be done more like this. It prepares soon to be engineers for what actual engineering work is like. Engineers don't come to work and get a list of tasks to do, along with instructions how to do them. Instead they are given a task and that's it. Nobody constantly looking over your shoulder and guiding you, its part of your own job to figure out how to get the task done.

These "textbook engineers" end up being employed as technicians despite having a degree or ending up employed in a field that has nothing to do with electronics.

But if you don't teach them enough theory what you get instead is a "copy paste engineer". They get things done but all of the designs they come up with are actually a bunch of existing designs from the internet or literature slapped together. They have no clue how any of those design snippets actually work, but they know what the snippet is for and are smart enough to put them together in the right combination to do the job. Results in clumsy non optimal designs that still mostly work in the end.
« Last Edit: April 26, 2019, 11:39:39 am by Berni »
 

Offline RoGeorge

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Re: top 10 uses for Function Generators
« Reply #27 on: April 26, 2019, 12:01:03 pm »
My Rigol DG4102 generator can output DC as well.  To my surprise, many times (if not most of the times) I am using it as an adjustable DC reference in the +/-10V range.   ;D

I have a 3 channels digital power supply, too, but I like to use it only for powering the circuit.  For reference voltages I like to use the AWG generator instead, don't know why.  :-//

Online tggzzz

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Re: top 10 uses for Function Generators
« Reply #28 on: April 26, 2019, 12:31:21 pm »
I completely agree, but bear in mind, someone just starting work needs to have a more academic bias if they are to end up a competent engineer after some time in industry.

If they start off with too little academic, theoretical knowledge, and then add pure on-the-job experience, then they'll become technicians - and may have missed the only opportunity to become the best engineers they could have been.

Just so. Exactly. There are exceptions, but they are so rare as to be almost mythical.

And the most irritating such technicians won't even recognise that's what can happen or has happened - and will prosyletise thie world view.

Those considerations are why it is so helpful to find what a candidate has done in their spare time, since that neatly complements the coursework and illustrates what they think they are capable of doing.
There are lies, damned lies, statistics - and ADC/DAC specs.
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Offline RoGeorge

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Re: top 10 uses for Function Generators
« Reply #29 on: April 26, 2019, 01:51:51 pm »
a perfectly spherical clock

What do you mean by that?

(Google doesn't fetch me any "perfectly spherical clock" either, well, it has something, but not physics related.)

Offline David Hess

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Re: top 10 uses for Function Generators
« Reply #30 on: April 26, 2019, 02:07:38 pm »
a perfectly spherical clock

What do you mean by that?

Perfectly spherical roughly means ideal and without extraneous behaviors or limitations, like the canonical "perfectly spherical cow".  So a perfectly spherical clock measures time perfectly, has no drag, rebounds with no energy loss, etc.
 
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Offline NorthGuy

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Re: top 10 uses for Function Generators
« Reply #31 on: April 26, 2019, 08:22:48 pm »
Ah, found my source from 1968, probably referring back to the late 50s. It wasn't in "Random Walks in Science", but the sequel "More Random Walks in Science".

Interesting. The most advanced student managed to get "almost" full grade, almost as good as others.
 

Offline RoGeorge

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Re: top 10 uses for Function Generators
« Reply #32 on: April 27, 2019, 02:03:00 am »
I don't get what's the fuss with that student.  There was no rope available there, and no ruler to measure the rope.

Zero points, no doubt.

Offline GregDunn

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Re: top 10 uses for Function Generators
« Reply #33 on: April 27, 2019, 06:39:59 am »
The problem with waiting until "on-the-job" to teach practical stuff is that it leads to people like we (actually, the company - we strongly recommended NOT hiring contract labor for the job) got to handle some software development on a time-critical project a few years ago.

They had all apparently graduated with "software engineering" degrees, which meant they understood programming paradigms, could write long screeds in Java, and tell their favorite IDE to build an object file.  What they did not know was how to deal with a design which wasn't in their received wisdom book of tricks, how to invoke custom scripts in a different language, or how to debug something which wouldn't run on the IDE.  They also didn't know how to pass what they learned on to their successors when the 18-month contract ran out, so if one of us got transferred to a different project in the meanwhile, they were back to square one using our documentation (which they couldn't interpret in the first place).  We were forbidden to do any of their work for them, or supervise the handoff to the project - that was done by their local supervisors who knew even less than they did. As we had expected, it was a disaster.

So I support anything in an engineering curriculum which forces the student to adapt their theory to real-world situations as part of the completion of a course.  None of us in EE could have built a class project in the first place if we didn't learn how to read a data sheet, compare specs and try out components in a test rig.  One of the most important things we learned in school was that the part specs, the requirements and the actual components often occupied three different spaces, and part of the solution involved dealing with apparent contradictions and hopefully finding a conjunction of the sets.  If I hadn't already done that as part of my course work, I would not have been welcomed into a R&D environment to build some pretty cool hardware - the project managers didn't have time to run a remedial course for engineers.
 

Online tggzzz

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Re: top 10 uses for Function Generators
« Reply #34 on: April 27, 2019, 07:59:48 am »
The problem with waiting until "on-the-job" to teach practical stuff is that it leads to people like we (actually, the company - we strongly recommended NOT hiring contract labor for the job) got to handle some software development on a time-critical project a few years ago.

They had all apparently graduated with "software engineering" degrees, which meant they understood programming paradigms, could write long screeds in Java, and tell their favorite IDE to build an object file.  What they did not know was how to deal with a design which wasn't in their received wisdom book of tricks, how to invoke custom scripts in a different language, or how to debug something which wouldn't run on the IDE.  They also didn't know how to pass what they learned on to their successors when the 18-month contract ran out, so if one of us got transferred to a different project in the meanwhile, they were back to square one using our documentation (which they couldn't interpret in the first place).  We were forbidden to do any of their work for them, or supervise the handoff to the project - that was done by their local supervisors who knew even less than they did. As we had expected, it was a disaster.

So I support anything in an engineering curriculum which forces the student to adapt their theory to real-world situations as part of the completion of a course.  None of us in EE could have built a class project in the first place if we didn't learn how to read a data sheet, compare specs and try out components in a test rig.  One of the most important things we learned in school was that the part specs, the requirements and the actual components often occupied three different spaces, and part of the solution involved dealing with apparent contradictions and hopefully finding a conjunction of the sets.  If I hadn't already done that as part of my course work, I would not have been welcomed into a R&D environment to build some pretty cool hardware - the project managers didn't have time to run a remedial course for engineers.

I don't disagree with the above, but it then leads to the question of where the balance should be.

Even if it was practical to teach the problems which occur in large (time/people) projects, I don't think it would be desirable. But the students should certainly have a clue that "here there be dragons".

Similarly, I wouldn't expect them to understand how to build, say, high availability distributed systems. But I would expect them to be aware of the relevance of the Byzantine General's problem and the "eight fallacies of distributed computing".
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Offline SparkyFX

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Re: top 10 uses for Function Generators
« Reply #35 on: June 06, 2019, 08:31:13 pm »
Suggest video on Top10 uses for function generators for someone who “does a bit of everything “.
The field is quite wide, so I don´t know if this would be Top 10, but anyway, besides testing other test equipment, like oscilloscopes and frequency counters
- OpAmp circuit input/output testing
- testing filters in general (although anything can be described as a filter function)
- slew rate testing of logic gates
- encoder simulation
- testing demodulation applications
- frequency source for microcontroller projects
- component testing

Of course you go by the datasheet in many of these cases, but in prototyping it might actually be useful to see where the limits are.
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Offline David Hess

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Re: top 10 uses for Function Generators
« Reply #36 on: June 06, 2019, 09:16:03 pm »
My most esoteric use involves either my swept function generator or two of my normal function generators.  I create a swept sine wave and send the sweep trigger to my oscilloscope or the reverse.  Then one channel of the oscilloscope measures the function generator output and the other measures the output from whatever network I am testing.  Combined, that makes a low frequency VNA (vector network analyser).  Since the oscilloscope is operating with a triggered sweep instead of XY mode, measurements can be gated to pick a specific spot to measure.  With alternate delayed sweep, the measurement point is highlighted on the oscilloscope display.
 

Online JPortici

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Re: top 10 uses for Function Generators
« Reply #37 on: June 07, 2019, 06:04:37 am »
One of the uses of integrated AWGs:
- There is a signal that upsets my board (reveals a bug)
- Acquire portion of signal
- From scope's AWG menu select the option to create waveform from acquisition
- Select the range to taste / normalize
- Apply.
- Now you have your test signal, go on debugging!

You can do it with any AWG of course, that's the whole point.. but it is so convenient to do with those integrated in scopes.
Literally the only advantage over standalone function generators (well, syncronized triggers too)
 

Online 2N3055

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Re: top 10 uses for Function Generators
« Reply #38 on: June 07, 2019, 08:52:57 am »
One of the uses of integrated AWGs:
- There is a signal that upsets my board (reveals a bug)
- Acquire portion of signal
- From scope's AWG menu select the option to create waveform from acquisition
- Select the range to taste / normalize
- Apply.
- Now you have your test signal, go on debugging!

You can do it with any AWG of course, that's the whole point.. but it is so convenient to do with those integrated in scopes.
Literally the only advantage over standalone function generators (well, syncronized triggers too)
I agree, same here. On Keysight 3000T you can also add noise to the signal easily to test for noise resilience on sensor input...
 

Offline Electro Detective

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Re: top 10 uses for Function Generators
« Reply #39 on: June 07, 2019, 10:48:11 am »

A function generator and oscilloscope and other basic test gear will quickly verify Audiophool equipment specifications  :o

and save wood ducks claiming to have golden ears from weeping golden tears blowing a ton of money on nicely badged generic equipment,
with price mark ups that are beyond any moral or criminal integrity  >:D

 

Offline RoGeorge

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Re: top 10 uses for Function Generators
« Reply #40 on: June 07, 2019, 07:25:53 pm »
This week only:

- searched for the resonant frequency of a NFC antenna located inside a Li-ion phone battery
https://www.eevblog.com/forum/rf-microwave/bamboozled-by-rx-voltage-nfc-antenna-resonance-(in-a-samsung-li-ion-battery)/msg2462037/#msg2462037

- improvised a Time Domain Reflectometer (TDR) to measure a coaxial cable's impedance, velocity factor and frequency response
https://www.eevblog.com/forum/rf-microwave/diy-50-ohm-bnc-cables-on-a-budget/msg2469279/#msg2469279


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