Review and teardown of the FeelTech FY3200S Product Link: www.banggood.com/custlink/mKK... Manual: www.eevblog.com/forum/testgear... This was provided free of charge for review by Banggood.com #ElectronicsCreators
I have found this video really helpful. I am a noob to electronics and value the information so much. After watching I feel confident enough to buy one of these and the linear conversion board. It will make a nice swap over project for me. The linear board is here I am waiting in the generator. Cheers :D
Nice review Steve, seems like it's not a bad performing Sig-Gen at all. Shame about the PSU but as you say hopefully changing the suppression cap will sort that out. Cheers John
I agree. The one thing I was waiting for and disappointed not to see was the display of the square wave at the highest frequency. It is where the less expensive function generators seem to fall down.
Just wanted to mention that the fluke 289 retains the main setting that the switch is turned to. But the soft menu sub settings like AC+DC or AC/Htz dual display options under menu does not stay retained. So every time you change the dial it resets to the default main soft menu option, then if you want a different soft menu option you have to select that option by pressing menu again and selecting the one you want. It's a slight annoyance for a meter of this cost when compared to some other Brymen recent models, I hope fluke will issue a software update for this and the menu user interface that could be a little simpler to use in my opinion.
I bought one of these FeelTech FY3224S 24MHz Signal Generators at the end of March 2016 and it has a slightly different version of the switching power supply. The suppression capacitor is a 1nF and I measured the current between earth on my scope and the metal sleeve of one of the BNC connectors as 28µA. I guess this is better.
First thing I will check is that leakage issue. Holy crap. I have two of the 20 MHz versions. Please show how to correctly hook up the unit as a frequency meter... mine just don't show anything, yet.
I have one of these too - I think mine is also the model with 1nf decoupling, since I certainly don't get shocked from it. However, I had to put vinyl tape around the lcd to get rid of light rays into the buttons and encoder parts of the front panel. ..and the worst part is that the signal really jumps all over the place when you get past a few MHz :( All in all, I'm not sure I would recommend this, unless you have very low requirements, and can get a very good price on it
Good review. I bought one of these but haven't even had time to power it up yet. Yes the leakage current is a bit of a worry but like you say, it's really easy to fit a small mains transformer with a split secondary, shouldn't add too much weight. There's a lot to be said for linear, too much reliance on digital these days I think and EMC becomes a bigger problem.
Excellent review. Watching the making of linear PSU, would you advise to use a buck converter for the 5v supply, and stay withe the making of transformer for the +12v and -12v supply's .. I might be scrimping omitting the 5v linear you made, but I liked to know if possible. Can you also point to your website please. Thanks
Quite a "shocking" discovery on the power supply. :) The digital stuff looks acceptable but they really need to fix the power supply issues. Sadly the batch has been manufactured so they will all get sold online in short order. There's plenty of room in the case for a timebase upgrade, but it looks like the main oscillator is 24MHz. I was hoping for 10MHz. Ah well. Looking forward to more of your videos!
Thanks for the review... I have one of those and I too am not happy with the PSU. May I ask, did you build or buy a replacement linear supply and if the latter was your choice, what module would you recommend? (My mains voltage here is 110vac). Thank you again...
Very informative video; I am not a big fan when it comes to switch mode supplies in test equipment. If there is to much leakage it can fry sensitive equipment and present danger to the technician, it may be cheap, but should not be recommended unless the modification is done as you suggested.
Nicely reviewed Sir! The power supply really is such a pity on otherwise a very interesting and feature packed piece of equipment for an unimaginably low price! Would be interested in how the sine wave looked at higher frequencies (is it usable / to spec. over the range stated), THD, square wave rise time spec /shape etc + a look at how the frequency counter compares. Very tempted to buy one and fit a PSU in it. It's worth it (for me) for the sweep function alone !
We will take a look more in depth in the next video on this. Unfortunately I don't have a spectrum analyser so can't see how noisy the waveforms are but we will certainly look how good they look visually
would give a 'sketch' of the state and higher end 'scopes have very extensive extra functions to further analyse the FFT but for the square /triangular wave patterns especially a visual inspection / rise time / etc gives a good idea of how usable those will be at higher frequencies where its much more difficult/expensive to design it and economies are evident. I bought a cheap (different) module and the square wave was indistinguishable from a poor sine above much above 2 MHz !
So a fix of sorts could be to replace the bypass capacitor with a 1nF one? Also is this an example where you would want to use a 'Y' capacitor for extra safety?
i just got myself one, and all i get from ch1/2 is a flat 10v dc, is there a switch or anything it does seem the unit is broken. trig ports on the back shoots and seems to work fine
Can you tell me please the behavior of the signal generator when the offset is at the extremes? On my generator, when I try to go with the offset at maximum positive, the signal become unstable and the frequency bounces around the designed value. Thank you for your answer!
Comprehensive review...well done. Need help!! I own a FY3200S. The LCD is lite, however, no text. Difficult to use with no text. Oscilloscope confirms the unit is working and the waveforms are normal. Troubleshooting indicates the LCD 3rd pin, VO, has no voltage present. VO traces to R1 which is open circuit... appears to be open. R1 side opposite to pin VO can be traced to ground... confusing. Cannot read the value of R1... maybe 220 ohm. Do you know the value of R1???? Also the voltage source that provides voltage to R1 is not known.... can you help.
Hello, I just bought a MOHOO function generator which I am presuming is a rebranded one of these as it looks identical. I got it from amazon uk for about 55 quid. I am a total beginner and want to use it as part of the Art Of Electronics course. Should I be worried about the fault? How can I test to make sure mine is ok? Also, do you need to plug a power supply into this as well? I have a TENMA dual output PSU on the way as well.
hola , perdón por preguntarte en otro idioma . Me interesa este generador pero tengo una duda - HAY ALGUNA DIFERENCIA ENTRE EL FY 3200S y FY3224S ?? los vendedores los ofrecen pero tengo dudas de cual comprar ,...gracias
If there are X and Y phase capacitors to ground at the input of the source and the device does not have a 3-pin power cable, it will dig. It's the same as breaking the ground pin in the socket and reaching for the PSU frame of the PC. It tingles.
It's been awhile you done this Video, Have they sorted the issue with the Power supply? apart from that, this was a great video for people like myself who just getting into electronics and building a cheep Lab.
I dont understand why my funcrion generator output voltage decreases as i increase frequency, that is really going to screw up my ability to test filters
Hi SDG_Electronics , I found your channel through this video, do you think this was a one off fault like you discovered? I was actually considering buying it but up until now I am a little hesitant! Would it be an easy fix like you mentioned? Great review nicely covered! I look forward to more of your videos :)
It's probably not a one off, but most seem to be fine - either way the replacement of that capacitor is technically all that is needed. If you have it plugged into your PC through the USB connector there'll be no leakage into your design under test and effectively would be no different to a more expensive signal generator that always has the BNC shield connected to mains earth.
Nice thorough review. Just curious, were you able to change the capacitor to a lower value on the power supply? Did it cut back on the current through the BNC connectors? This unit looks like it will cover what I'm looking to use it for, but I don't feel like damaging my Rigol scope or other equipment.
+Gadget Review (GRV) Yes the capacitor value can be dropped to 1nF to get a more acceptable current. You can also replace the mains lead or connector for one with an earth and earth the 0V on the secondary. Part 2 is almost ready with a complete replacement with a linear power supply.
So I presume that USB to serial converter does not isolate the signal? If so then if you earth the device it will earth the USB also. Potential for ground loops? I suppose that as the device is currently you will get current flowing back into the USB channel too.
I'm going to earth the pcb ground and swap out the transformer cap. Can you specify the best cap for the job? Thanks, good review.. Too mess about with different ps would cost more than the unit.
Here in the states you can get small power transformers for a few dollars and the linear regulators and electrolytic caps for a small perf board power supply would be about the same as the transformer. In other words less than $20 or about 10 quid for a reliable regulated power supply.
This is just an observation on electronic test equipment bought from any of the Chinese online stores that are just a version of Ebay. The observation - I found while looking for an oscilloscope is that I could buy the model I wanted for AUD60.00 less than the cheapest Chinese price and have it delivered express next day for free. The big plus being the strong consumer laws we have in oz that you do not get from the OS stores. So none of this rectifying (pun) poorly designed power supplies - it is just return it and the merchant is responsible for all reasonable return costs.
I'm new to function generators, so I hope you don't mind me asking this... When you measured the current on the BNC connectors with respect to ground, you measured the current between "earth" ground and the BNC ground, is this correct? Why is this measurement important?
+akhurash What is measured is how isolated the BNC of the generator is with respect to the real ground which is the ground of your mains socket. Ideally the generator should be floating (like if it were running on batteries) so no current can flow at all. But since it uses a main supply there is some leakage so some current can flow. This is an unwanted side-effect of the switching type mains supply used in this generator. An "old fashined" linear supply with a mains transformer would provide better isolation. You want good isolation to prevent unwanted currents flowing into a sensitive pin on a chip for example. The current this generator delivers through it's BNC ground would be enough to damage an IC.
Great video. I have the 3200S with the leakage issue about to be fixed. Anyone have access to English language software for PC connection? The CD sent with it is useless.
It helps to prevent the output of the power supply and your device acting like a big antenna for all the switching noise. Instead it's coupled back to the source.
Can this unit provide a modulated signal suitable to align if cans in an am radio, (maybe using both channels). Any help would be very much appreciated, cheers.
Why did they place ground symbol near BNC connectors? On the second thought when you connect it to the computer via USB it will become ground referenced. I don't like this device. Thank you for very interresting video! BR, Jacek.
I got one of these back in November of last year and I used it once and I wasn't aware of this issue with it. So before I use it again I want to make sure that I don't have this issue. I did not understand one thing you said about the capacitor. The suppression capacitor and what type and size. Although I did understand when you said it should be a 1nf. but what was the value of the original and the type of it so I can tell if I need to replace it in my unit? I appreciate a response. thank you. :-)
The reason why I'm asking is because I took mine apart and I found out it's completely a different power supply board that don't look anywhere near to the ones I seen on youtube videos including yours. so I can't tell if it's newer or older. But when I got it it was in pretty rough shape. The front clear area of the display scratched, one of the rubber feet missing. when I contacted BangGood about it they said it WAS new and as long as it was working the only thing they could do was give me credit points for my next order. Which I didnt think was right. But to avoid shipping it back and having to pay extreme shipping rates from the New York State and then on top of it waiting another 3 months for replacement, I accepted the offer. That's what I am saying I don't know if I have an older version or a newer version of the power supply. I cannot see the markings on the capacitor that I ASSUME is the EMI suppression capacitor, because the letters are worn off on the capacitor. So right now I'm at a loss. :(
can anyone help? As I said the power supply built into my feeltech fy3224 does not look anything like the power supply that you have from your unit. Or anybody else's I've seen on RU-vid. That is why I'm wondering if I either have an older version of the power supply or a newer version of the power supply as I can't tell the value of the capacitor. Or if it even is EMI suppression capacitor. can anybody tell me how to post a picture? I have a picture on my Google Plus page. and I want to post it here so you can give me an idea what I should to do. I also like to note that it is all filled in with some kind of white glue epoxy as you'll be able to see in the picture itself. I appreciate some information asap.
Hi, I've only just seen your comment for some reason. There are a few different PSU designs going around - if you visit the EEVblog forum, you should find a thread there with other pictures. The capacitor fitted to mine appeared to be 10nF.
Despite the power supply issues this is a quite nice device. Has anybody found out wether it is possible to get a trigger signal out of it at the start of a sweep? 73, Andreas.
Thanks, had a look. I like the convenience of this unit except mine has two issues that may be design issues rather than problems with my particular unit - and wondering if you also see them. I am using a 500MHz analog bandwidth scope with a 500MHz 10x probe. When look at the unloaded output of the unit I see very strong glitches at around 250-300MHz on the sine wave output. I don't see these when going directly into my scope configured for 50Ohms. Not sure what the trigger bandwidth is on the rigol you have, and whether of not you will see it, but the result would be a perceived jitter if you adjust the level and it may trigger just above the waveform amplitude as sometimes when I turn it on the spurries are on the peaks (other times in the guts). I also am very confused about output levels. If I am supposed to use this unit with a 50Ohm load, then shouldn't to LCD set voltage correspond to loaded voltage? The LCD lines up very accurately with the unloaded output but does not with the loaded output. Really there should not be such a dependency at all!
Steve, One more question. I have a power supply for outdoor lighting. It is 120VAC 60HZ primary and 12VAC 60HZ 44W output. I want to build a full wave rectification circuit to swap the incandescent bulbs for LEDs. The diodes I have rated for 150V & 5A (overkill I know but it's what I have). The FV is .85V for each diode. The LEDs are 3watt & have a FC of 700mA each and a FV of 3.8V each. I calculated I'd need about a 4-to-5uf cap to smooth out the voltage. Does this seem accurate?
If I place the resistors in parallel, assuming there is enough voltage present at the supply, and add some low ohm power resistors, will I still need a current limiting circuit?
Hi am wondering if you can help me. Ive got one of these and I cant find software or driver for this to run on windows 10. The little cd that came with it I cant find. Can you help? Id be so grateful !!! Thanks
Its probably your accent, but what are "book capacitors"? I'm sure I'm just not hearing you right. I'm assuming you mean filter capacitors but I'm just not sure of the word you are using. Thanks for the review. Can you do one of a scope? I've seen those kit scopes on eBay but they are probably garbage. 200khz bandwidth too (would probably be fine for me since the fastest thing I think I would probe is a smps).
+SDG Electronics I thought that's what you were saying I've just never heard them called that before. Cool about the scope. They're only like $20 but its a diy kit with a decent amount of soldering..
+David Pilling It appears from photos that there are a couple of different power supplies used in these units. IMO the outputs should be completely floating or tied to mains earth.
+SDG Electronics I agree. I'm looking to modify my unit. It came with a "death 'o' dapter" plus 2 pin plug, and at the very least I will put a three pin IEC socket on the back panel. Someone on the EEV blog forum suggested using a capacitor to earth, which would short the main leakage out but allow a DC voltage difference. I expect there is no escape from an old fashioned mains frequency transformer power supply.
+error079 1) load arbitrary waveforms 2) control the device (select waveform, amplitude, frequency etc.) There's a Windows program to control the device. I also managed to control mine by using Python and this library: github.com/atalax/python-feeltech
Did you power it from the wall without added isolation transformer? In other words, could I plug my scope bnc channel 1 to the channel 1 of this signal generator? (with both scope and signal generator powered by mains with no extra isolation transformer)
I order one. I love it. So far I have had no problem testing wall connected circuits with my scope with input signals from this sig gen. I think the main thing to watch out for, is any connection with high voltage potential, that has a direct short to ground. As this would cause high current to flow
Just ensure whatever pin connections to the Arduino, will not exceed Arduino pin specs for amps being pulled, and conversely, will not exceed the max voltage. So for example, if you connect your sig gen to an analog input pin on Arduino, just look at the specs for the Arduino pin first. They have good documentation.
Are you (or any viewers) aware if the manufacturer has addressed the power supply issues with this model in the almost three years since this video was made? I am a beginner using Arduino/low power components, and I certainly don't want damage anything by making any Newb mistakes...
The new models don't have the same high leakage, but I'd still recommend making some modifications. The simplest is to replace the 2 pin connector with a 3 pin connector for the mains supply and connecting the earth pin to the chassis/electronics 0V inside the unit
@@sdgelectronics Thanks for the response. Yes, that looks like the best approach. I figure i will just mount a ground stud on the back and put a grounding point on my power strip, that way I avoid mangling the case too much and I need an alternate ground point, anyway, for other things. Thanks for the videos!
I liked the review, but I had an absolute facepalm moment when you said you aren't sure why they put that 50 ohm recommendation in. Go look up characteristic impedance, impedance matching and standing waves.
I fully understand impedance matching and transmission line theory, but the output voltage on the LCD is incorrect into a 50R load. Most signal generators you specify if your driving a Hi-Z or 50R load and the amplitude is adjusted accordingly yet this is set up for a Hi-Z load not a 50 ohm load, hence my comment...
Generator of Functions everyone put the generated direct connected in the ociloscope more nobody put or knows how to use the generator in test in the circuit ??????? just showing the generator on the oscilloscope is of no use as this anyone knows how to do
Wait what the hell? How could it just float to close to 95V? Isn't that incredibly dangerous? Why are you so casual about it? It's supposed to be about 10v and it's almost an order of magnitude larger. Why is this?
The manuals are written in Chinglish. You always have to guess the meaning of the poor grammar. Is there anybody in all of China capable of writing in understandable English?
