What is meant by a waveform generator

Forum: Microcontrollers and Digital Electronics Why do you need function generators?





Hi, what do you need function generators for? I can understand a laboratory power supply to supply electronic components with voltage. Also an oscilloscope to see what the electronics are outputting. But what can I do with a function generator that creates rectangles, triangles, sine waves and such?



If you want to repair hi-fi equipment / measure frequency response, you will need a clean sine. You need the square pulses to feed digital circuits. An FF only switches cleanly with steep pulses.



Measurement of amplifiers or controllers. Determining the cut-off frequencies. Determine answer to a jump. Testing when visible distortion occurs. Measuring the distortion factor. Testing speakers. Determine the resonance frequencies of mechanical structures. ...



Malcher wrote:> Hi, what do you need function generators for? A laboratory power supply can> I> understand to supply electronic components with voltage. Also an> oscilloscope to see what the electronics are outputting. But> what can I do with a function generator that creates rectangles,> triangles, sinusoids and so on? look like an amplifier changes the waveform? in good German, distortion factor measurement http://de.wikipedia.org/wiki/Klirrffekt nowadays rather with DVB you not only have to look at the level but also and especially the distortion, nothing else than distortion factor which leads to a high bit error rate . http://forum.chip.de/tv-empfang/gute-signalstaerke-hohe-bit Fehlerrate-1793513.html



Malcher wrote:> But> what can I do with a function generator that creates rectangles,> triangles, sinusoids and so on? You can enter its signal into your circuit at the front so that you have something to look at with the oscilloscope at the back.



Malcher wrote:> Hi, what do you need function generators for? A laboratory power supply can> I> understand to supply electronic components with voltage. Also an> oscilloscope to see what the electronics are outputting. But> what can I do with a function generator that creates rectangles,> triangles, sinusoids and so on? Admittedly a bizarre thought, but you could use a function generator as a signal source, for example.



Joachim B. wrote:> see how an amplifier changes the shape of the curve? >> in good German, distortion factor measurement >> http://de.wikipedia.org/wiki/Klirrffekt I read it through, unfortunately I didn't really get it Roger that. Does distortion factor mean - the more harmonics you have - the worse it is?



E.g. you need the ... in order to defuse lost µçs ... ;-) but not always succeed

: Edited by user

If you want to measure where the limits of a circuit you have developed lie, you have to feed it with increasingly difficult input signals until it no longer delivers a usable result. A function generator is normally used to generate these input signals and to be able to adapt them easily. In addition, it is very practical in everyday laboratory work to quickly generate a rectangle, a PWM with xx% and nn kHz, sine, voltage, DC offset etc. and to be able to change it at the push of a button / rotary knob. Most of it could be put together with a few opamps, potentiometers and transistors on the breadboard. The simple operation, reliable frequency and voltage information, integrated short-circuit and overvoltage protection, ... a proper function generator save you a lot of time and frustration.



Yves K. wrote:> E.g. you need the> ... in order to uncover lost µçs ... >> ;-) but it doesn't always succeed oh, what a shame.



Gerd E. wrote:> In order to generate these input signals and to be able to adapt them easily> a function generator is normally used. Oh, so I could, for example, add a square-wave pulse to a longer line, which should be exactly the same as e.g. a square-wave pulse from a data transmission signal, in order to then see whether it still arrives correctly?


Malcher wrote:> Oh, so I could, for example, put a> square pulse on a longer line, which should be exactly the same as e.g. a> square pulse from a data transmission signal, in order to then> see whether it is still arriving correctly? Exactly. And then you turn the wheel of the FG and "sand down" the square pulse more and more. You keep doing this until your signal is no longer correctly interpreted. Now you know where the limit is and how far you are normally away from it.



Malcher wrote:> Oh, so I could, for example, put a> square pulse on a longer line, which should be exactly the same as e.g. a> square pulse from a data transmission signal, in order to then> see whether it is still arriving correctly? hmmm, after several 100 meters everything arrives, just not what you feed in at the entrance. So it depends on the "longer line". Greetings Asko.

: Edited by user


In the last few weeks I have used it in my work for the following: - Testing motor bridges without having to write programs - Modulation / demodulation of signals (mine can do FSK, AKS etc.) - Clocking a µC - Measurements / tests of audio amplifiers - Frequency response measure filters - measure parameters like tphl / tplh - test power switches - test PWM controlled circuits without firmware - annoy apprentices (I don't hear 18kHz, but they do :-)) and much, much more. I really miss such a thing at home, but it's too expensive for me. Often a µC does it. but that takes longer and has the problem of a frequency that is not continuously adjustable.



You can use it to output a sound quickly using a piezo and a loudspeaker. Using an additional 2 channel oszi, check a transistor circuit, i.e. what the input and output signal looks like. As a clock source for a fuzzy AVR, this is faster and more flexible than with a quartz oscillator. Check Schmitt triggers or comparators (sawtooth or triangle) Since the cheapest ones are usually 1-2% distortion factor, I would not necessarily use that for an amplifier. Signal tracking on a circuit board Measure crossovers if you have no component values.


Malcher wrote:> Hi, what do you need function generators for?> But> What can I do with a function generator that creates rectangles,> triangles, sinusoids and so on? Check debouncing of inputs, generally stimulate control inputs such as trigger input from cameras, light barriers, etc. and thus check behavior. The triangle is a good way to determine switching thresholds. Kind regards,



But joking aside, I had asked this question once and when I now had to deal with audio a bit, I first noticed "how awesome" that part was. I was finally able to see a smart signal. Also see how well the filter works. For the few euros that the lower price range costs, you can't go wrong. The saying always applies: Tools are never gone and you can never have enough.



what for man I can't say in general that function generators need ... Here I looked up how different diodes react to different frequencies: Article "Re: Cut-off frequency of diodes?" The last time I used one was when testing an opto-coupled PWM-MOSFET amplifier circuit for a ~ 500W heating bed. is incredibly practical when you can press the button and turn the knob to set frequency, vpp, duty cycle and voffset.



function generators can also be used to test VHF radios. Simply set it to the desired frequency, plug a piece of wire into the socket and then you can receive the signal on the radio. Good generators also have a modulation input, for example. add a sine wave (FM mod.).



... and why, please, a spectrum analyzer? Sure, somewhere for the HF range, filters, etc., but is such a device also useful / necessary in the ATMEL hardware and software development area?



you can also sweep it often with it while your generator runs through a sine wave with increasing frequency you can test your circuit how it behaves or with an abitrary function generator you can generate any signal that you have previously recorded for a special test.



Karle wrote:> but is such a device also useful / necessary in the ATMEL area> hardware and software development? Yes. To see the frequencies at which you are messing around with your digital switches. You can get active before the EMC test ...

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