7$ Function Generator VS 107$ Function Generator


When it comes to useful tools on the workbench of an electronics hobbyists then you can never leave out the so-called function generator It can generate different waveforms like a sine triangle or square shape with adjustable amplitude and frequency So it’s perfect to for example calculate the inductance of a coil provide test signals for audio amplifiers or for powering prototype resonant circuits now the function generator route that I’ve been using for over a year costs a total of 107 Dollars which might be a bit too pricey if you’re just getting started with electronics but thankfully there also exists cheaper function generator kids like this one for only seven dollars so In this video let’s find out whether such a low budget kids can compete against a $100 more expensive model Let’s get started First off. I must say that [I] was rather happy about the PCB year and acrylic last quality of the seven dollar kids After unfolding its manual and making sure that all the required components were inside the packaging I started by placing the resistors on the PCB according to the values mentioned in the parts list and soldered them in place Then I snapped off the excess leads and repeated this procedure for [the] rest of the components starting with low ones up to the highest ones after Only 15 minutes all the components were soldered in and all that was left to do [was] to insert the IC Which is a XR-2206 function generator IC Now we could just grab a 12-volt power supply [hook] it up to the circuits and use it just like that But since the manufacturer included nice acrylic case for it, I secured the standoff bolts to the PCB I place it all inside the acrylic cage and close it all up with the top piece and four additional screws After adding the adjusting knobs for the potentiometers. I powered the circuits and connected the ground and square wave output to my oscilloscope Which is mandatory adjust the waveform since in contrast to my old function generator This kit does not come with a screen and of course you don’t need an expensive Oscilloscope like mine, a cheap oscilloscope kits also does the trick Now we can change the frequency range of the square wave by connecting different timing capacitors to the IC through a jumper The minimum frequency for all waveforms is around 700 Millivolts and the maximum frequency Goes up to 1.4. Megahertz which is not bad, only problem Is that the waveforms are all rather distorted at the maximum frequency so I would say that usable up to a maximum frequency of only 500 Kilohertz as a comparison my other function generator can create a decent sine wave up to 9 Megahertz, a Square and triangle wave up to 2.5 Megahertz, and has a minimum frequency of 100 MilliHertz But an advantage of the cheap here is that the peak to peak Voltage of the Outputs is around 2 to 3 volts higher than the expensive one Which means that we should be able to draw more current? right? Well, not really because what is important for that is the output impedance Which is 50 ohms for the expensive function generator. you can think of it as an additional resistor at the outputs. Which thus decreases the output voltage proportional to the flowing current For example my Eneloop battery can easily supply 3.4 amps of current Without its output voltage collapsing because of its low impedance of only 25 milliohms But on the other hand, the output voltage of my usual function generator almost disappears completely here when drawing around 28 milliamps Now the cheap kit comes with an even higher impedance of around 600 ohms according to the data sheets But after I did some tests the impedance is more likely around 800 to 1000 Ohms So definitely less current for our circuits another disadvantage of the 7 Dollar Kits is the DC offsets that every waveform comes with This means that everything we want to power will draw a DC current in addition to the AC current Now of course you could add a capacitor in series to get rid of these effects But I would still prefer the DC offset knob of my old function generator Finally I would like to mention the design and triangle waveform require some fine amplitude adjustments unless you want the top and bottom piece to be cut off and The amplitude of the square wave is also not adjustable All in all you get what you pay for if you want a super cheap But bare-bones function generator that delivers its promises with a couple of hurdles then you can go for it But if you want a reliable tool that is more convenient to work with and has more advanced features off its sleeve Then I recommend you to spend the extra money of course you could also spend way more money and get yourself a function generator that can create arbitrary Waveforms, but that is a subject for another video until then don’t forget to like share and subscribe Stay creative and I will see you next time

100 thoughts on “7$ Function Generator VS 107$ Function Generator

  1. What a great channel. I really enjoy your videos and learn a lot from them.

    Can you please tell me the ebay seller you bought your oscilloscope from? I bought one after I watched your video but it is dead on arrival and I am fighting with the seller to get my money back. If you can tell me the seller (or give a link), I can buy it from there.
    Thanks

  2. If I want to know everything about electronics what should I do ???????
    Will you please suggest me some books on this things I mean in electronics….
    I am a big fan of you and I love physics…

  3. Where did you get that case for PCB? I need something like that for my function generator. Thank you very much 🙂

  4. I have an app for dmartphone called function generator and it works perfektly for standard things

  5. You could try to add that capacitor and feed it into an op amp setup as a voltage follower with a bjt or mosfet output stage

  6. lol i'm a cheapskate so i just use a USB sound card with audio amp to generate arbitrary waves. i ripped out the capacitors to be able to supply low frequency. works ok.

  7. Got the same one for R170.00 ZA. Was wondering about the the DC offset… Got a GW 20Mhz crt scope for free!!! Thanks for your work.

  8. How about a challenge, lets take that cheap function generator, add an Arduino and some code, as well as a 16X2 LCD screen to come up with something a bit closer to your expensive unit, but with a manageable price for we who are no longer among the working hobbyist?

  9. Dear Scott, what kind of Oscilloscope do you use? Can you please provide a link? I'm building my work station and I'm confused about all the oscilloscopes, and how to choose a good one that is accurate, reliable and affordable.

  10. So if you're putting out a MHZ, especially by connecting the frequncies to your body, does it affect the ears in some way so as to make you lose your hearing? I know microwave ovens don't do this, but is it true in this case?

  11. If you're trying to set up an electronics lab on a budget, I'd recommend avoiding the ultra cheap equipment and just buying good quality used equipment on eBay. For $50 or so you can pick up used Tektronix scopes, function generators, or whatever else you need. In the long run you'll probably end up needing their better quality anyway so may as well skip the cheap stuff and go straight to eBay.

  12. You could also, if you already are buying a decent oscilloscope, choose a model where the function gen. are integrated. I have been very satisfied with the integrated function gen. in Keysight scopes.
    But nice video

  13. Scott..love your work. Scott can you please send me your oscilloscope spec. and how and from where to buy if it's cheap..😜😂

  14. It's easy to put a switch on that frequency changer. And a more powerful output transistor could fix the lack of current availability while lowering the impedance to a more acceptable 50 ohms. Thanks for showing us the differences in a very professional way.

  15. Love your projects man! I am an Electrical Engineering student, and I want every one of your videos….I learn more from them than I do my lectures.

  16. They could have probably added an op amp buffer or push-pull output to the $7 one and vastly improved the output impedance without drastically altering the cost.

  17. Lmao mine function generator can generate all waveforms at 1 gigahertz frequency

    Lmao not really i dont even own a function generator :/

  18. i got a 20 kg function generator from my dads work becues it was borken
    now i have fix it and am never gonig to get rid of it cues that is a one in a life time.

  19. I bought a siglent arbitrary function generator of about 35MHz about a year ago for around $350. I’ve used it maybe twice. Those two uses earned me twice its cost. This $7 kit would have sufficed.

  20. Hey there,
    There's another cheap DIY function generator kit on AliExpress that has a screen and buttons. It's bigger than the DIY kit in the video and it's around US$8. You might want to try it out.

  21. Can i use it on load buy connect it to optocoupler to feed mosfet with 300khz squre wave? https://youtu.be/GopZJKdCqrA?t=231

  22. Get the cheap one. If you don't have an oscilloscope you'll never know the difference.
    Just kidding.
    There's some snazzy function generator on Android. How do these compare with the real thing? Is it possible to use the audio, say in the case of http://www.wolphi.com/interface/ a Wophi link?

  23. I have had one of those little kits now for a couple of years, it does the job for me when I need such a thing. That said, it is rare that I am in a situation where I actually do need it. The last time I used it, if I remember right was when I built one of those cheap oscilloscope kits, just to test the scope! Guess it worked for that. I have a signal monitor deal that I can hook up to it if I need to set a specific output frequency, that was a couple of bucks more on Ebay.

  24. Hi I like your video. I'm no techie. I wanted to use one of these cheap generators for PEMF. F.e. to generate the Schumann resonance frequency 7,83 Hz or solfeggio frequencies.Would you recommend them for this frequencie range?

  25. I'd really li8ke to hear your thoughts on the Hantek 2D72 Scope/DMM/Arbitrary Waveform Generator. Based on this video, it sounds like One can expect to pay significantly more than $107 for an AWG alone. So $170 for the AWG and Oscilloscope sounds like a steal. Though on this subject, I'm entirely clueless. Personally, I believe it's an incredible little device at an even more incredible price. But I wouldn't be able to tell if it was so off that it's useless. So I'd LOVE to hear someone with a great deal more knowledge than I have weigh in on the subject

  26. Yes, a video on the oscilliscope kit would be awesome. You got my hopes up there brother, for a second I foolishly thought I could avoid paying 100+ for a functional generator. But as you say "You get what you pay for". You pay peanuts you get monkeys, right? And so on. Many thanks GreatScott for another upload.

  27. I do still like these cheap little kits. Lets face it, you`re not going to be relying on them for accuracy or real lab use, but they are a great way to introduce someone to electronics. They`re more than capable of demonstrating basic principles to a young student and giving them good practice at construction and soldering. All at pocket money prices too.

  28. I actually wouldnprefer the nicer signal generator. I would use that cheap one fir a DRSSTC driver interrupter if possible.

  29. Sir since Chinese kits never come.with directions did you find any on the internet and were ,if you could please help me ,I want to build that kit to for my pocket ocilloscope .

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