IMPORTANT: The fix shown in this video is dangerous and should not be used. I've made an update video on how to properly fix the mains coupling issue. You can view that video here: kzread.info/dash/bejne/lHasktuGmrWuYrQ.html

@matix2120

3 жыл бұрын

Video is private. Can you publish it?

@TimsElectronicsLab

3 жыл бұрын

Hi Matix! The video is scheduled to be released next week, but you need to remove the blue capacitor next to the optocoupler and connect the earth wire directly to the GND of the system instead of through a resistor first

@matix2120

3 жыл бұрын

@@TimsElectronicsLab Can I have an early access please? :) I'm about to receive fy6900 tomorrow and I'm a little afraid of using it due to that AC voltage on BNCs.

@TimsElectronicsLab

3 жыл бұрын

@@matix2120 I can imagine, try to measure if the voltage is there, if there is, connect the system ground to the earth prong on the 3 pin mains connector. Just don't add the resistor.

I don't really understand why you upgrade the earthing wire to a proper diameter, when you then put a puny resistor in series with it.

@TimsElectronicsLab

3 жыл бұрын

Haha yeah, that's a good point! I was probably better off having a couple of resistors in parallel, diameter wise

@CedricThomas34

3 жыл бұрын

Same question for me!

@vizkoze

3 жыл бұрын

That resistor defeats the earth grounding purpose. If you short something out, the earh leakage protection won't kick in..

@TimsElectronicsLab

3 жыл бұрын

The resistor is preventing an earth loop

Congratulations! :D

@TimsElectronicsLab

4 жыл бұрын

Thanks!!

Hi, I couldn't see how you tested those voltages on the ground. I have just bought one but don't want to open it in case they upgraded it. How do I test first?

@TimsElectronicsLab

Жыл бұрын

Measure the voltage between GND and mains earth. That should be 0

Hi Tim, What was the wattage and resistance did you use for the resistor? Great video 👍

@TimsElectronicsLab

3 жыл бұрын

Hi Jack! I think I used a 10k resistor but I don't remember it. It should be on the eevblog forum, just like the other solution that uses diodes. I'll make a follow-up video soon!

@jackdock291

3 жыл бұрын

@@TimsElectronicsLab Sounds good and thanks for all the info👍

Hallo Tim, Leuk dat je video's maakt maar naar aanleiding van dit verhaal zou ik maar eens wat huiswerk doen: Veiligheidsaarde zacht maken met een serieweerstand is geen verantwoorde of juiste manier om aardlussen of offset-spanningen te voorkómen of bestrijden. Je geeft potentieel levensgevaarlijk advies.

@TimsElectronicsLab

3 жыл бұрын

Hi Raymond, I'm aware of it and I'm working on a new update. I got this information from the EEVBlog and I consider that a very reliable source of information. Jim, who has also commented on this video has given a solution, that I will make a follow-up video of

@raymonddompfrank1789

3 жыл бұрын

@@TimsElectronicsLab Hi Tim, thanks for your reply. Unfortunately, I haven't been able to find anything re. the problem, i.e. what is it? Do you have a link or term to use on Google? Also, stupidly, I hadn't seen Jim's reaction or I wouldn't have given my reaction the way I did. Sorry about that.

@TimsElectronicsLab

3 жыл бұрын

No worries! The problem is that there is 90VAC on the GND of the BNC'S and according to the forum post on the eevblog you can put a resistor in series and connect the GND to earth. www.eevblog.com/forum/testgear/re-feelelec-new-arrival-fy-6900-signal-generator/msg2635677/#msg2635677

@raymonddompfrank1789

3 жыл бұрын

@@TimsElectronicsLab. First, I have to say I have no FE6900. Second: Sorry for the lengthy post. I couldn't make it shorter without losing its meaning. In his answer to Jim, Tim said: 1. "So if I recall correctly, I should remove the Y cap and connect it to the earth of the AC connector. 2. Then I shall connect the BNC's earth straight to the AC's earth right?" and also 3. "And the other side of the Y cap should be at the GND of the mainboard?" If I interpret this correctly, it says: A. "Y-cap" must be connected (1.) between AC earth (which is safety earth) and (3.) mainboard GND. B. In 2. it says that "BNC GND must be connected to AC earth". That is correct because normally, all "chassis-like" things, like BNC bushes, which are almost always connected to the mainboard GND, are connected to safety earth, which is AC earth. So, mainboard GND is connected AC earth. If connected this way, the Y-cap is shorted and has no function. - Y-caps are connected between each phase and safety earth, so they usually come in pairs. In places like Europe, no strict prescription about the phase connections exists. - X- and Y-caps are used to suppress noise coming in (and going out!) over the mains lines. It only makes sense to use two Y-caps (between AC phase and earth) and a single X-cap between phases. One "Y-cap" makes no sense, definitely not in Europe. - X- and Y-caps are placed as close as possible to the mains entry and certainly not on a device downstream that is fed by a switching power supply. Summing up: I don't think the cap really is a "Y-cap". I don't know where it is located but it seems to live on the mainboard. Maybe it is a noise suppression cap on the main board, in which case its connections should be made on the main board. A separate connection should go from the main board to mains (AC) earth. The wire that was replaced by a thicker one serves that purpose. Ground loops are common, are sometimes caused by safety good practice and requirements, and should be dealt with on a signal level, not on an earth/mains level.

@raymonddompfrank1789

3 жыл бұрын

I also wrote a reaction to Tony Albus (another fellow Dutchman) this.

I put my multimeter to volts and put the black lead on the ac earth of the plug and the positive lead onto the earth of one of the bnc connectors. It gave an 18v reading. Do I need to modify it to show zero?

@TimsElectronicsLab

Жыл бұрын

Yes you do

@ForSynthsSake

Жыл бұрын

@@TimsElectronicsLab I decided to send it back, I will look for a more expensive one, any recommendations for a hobbyist?

@TimsElectronicsLab

Жыл бұрын

Not sure to be honest. Maybe there are some opensource variants. If you do find one, please let me know 🙂

Hallo Tim, wat is het nut van de 10Kohm weerstand naar de aarding van de IEC connector ? Tevens haal je 2x een netsnoer en multimeter bij, de 1ste keer laat je gewoon zien dat er 220V aanwezig is op het netsnoer, en de 2de keer na de "fix", haal je opnieuw het netsnoer en multimeter bij en word er niets getoond. Ook word nergens in de video getoond wat het werkelijke probleem is.

@TimsElectronicsLab

3 жыл бұрын

Hi Bjorn, That is to prevent the GND from floating (@50V AC) This can potentially be dangerous for you and your electronics so I do recommend this mod.

@BjornV78

3 жыл бұрын

@@TimsElectronicsLab , blijkbaar hebben onze reacties mekaar gekruist :-) Ik had al een vermoeden dat het lekkage probleem naar de BNC connectors het probleem was, maar origineel was er al reeds een aarding aangesloten vanaf de IEC connector naar de print toe, welke deze lekkage zou moeten doen verdwijnen. Ik snap dan niet, dat een weerstand van 10Kohm toe te voegen, dit probleem zou oplossen, aangezien dit zorgt voor een slechtere verbinding met de aarding, en het probleem gaat erger maken ? De 50V AC wat blijkbaar aanwezig is op de BNC connectors (wat niet getoond word in de video), word veroorzaakt door de blauwe veiligheids condensator tussen primaire en secundaire zijde van de pulstransformator, ter preventie van EMI. Maar zoals ik al vermelde, door een degelijke (lees zo laag mogelijke weerstand) te hebben tussen de massa van de BNC connectors en de aarding, hoe minder of zelfs geen lekkage aanwezig is op de BNC connectors.

@TimsElectronicsLab

3 жыл бұрын

Then they might have fixed it, I'll reopen my unit soon as I'm not satisfied with the thickness of the connection. Thanks for your response! I can learn a lot from it

Hi Tim for me it makes no sens to change the earth wire and ley earth only by resistor to ground. What I have picked up is how difficult opening is. Thanks

@TimsElectronicsLab

3 жыл бұрын

Hi LemmisTube, Thanks for your comments! You've let me wonder, why doesn't it make sense?

@alssilva8496

3 жыл бұрын

Faz sentido mudar porque o fio terra é muito fino por um de 2,5 mmm por segurança

@TimsElectronicsLab

3 жыл бұрын

Thanks for your comment! I'll do some research and probably make a follow up video!

@takeo3998

3 жыл бұрын

@@alssilva8496 a dúvida está ocorrendo porque se vai entrar em série com um resistor de 10k, a corrente fica limitada a valores muito baixos, então para quê ele colocou um cabo mais grosso?

@takeo3998

3 жыл бұрын

Why upgrade to a thicker cable for the ground if it's in series with a small resistor (10k? It would pull any current way down), and if there is a current high enough to melt that cable, the resistor would blow up first... anyway, I think it can be interesting to measure any voltage over that resistor, as I heard those generators use to shock a bit. Don't know if it's true!

I'm just taking a shot in the dark for information here, but you don't happen to know if there exists schematic and source-code for the programmable devices on the PCBs? I'm interested in, if possible, using the same type of AWG together with a 4-channel 200MHz Siglent DSO, and would like to, if possible, modify the protocol it speaks over USB so it can directly interface with the Siglent and produce bode plots without needing to add a USB-8pinTTL translation device in-between. Any information is appreciated, even such things as frequency stability, output driver impedance accuracy over a wide frequency interval etc. Btw I think the DSO you connected the AWG to has 1Mohm inputs, so you should use 50ohm BNC terminations on the inputs to avoid reflections/standing waves i you're looking at anything with higher frequencies. I have always found common grounding of test equipment a real pain, since it always leads to a complete mess signal quality-wise, maybe it would be better to convert to using an external wall-adapter and adding a separate ground banana-socket that allows it to be connected to a common ESD-rail instead? I wonder, could you perhaps check how the incoming USB signal path is routed - does it go to a FTDI-chip and get mux:ed together with the TTL-wired on the back, or does it have it's own path into the FPGA? I'm asking in preparation for my own future instrument acquisition, where I would ideally like to maybe buy a cheaper FeelTech AWG with only USB connector, but modify it with a MCU to pretend over USB to be a Siglent AWG..

@TimsElectronicsLab

3 жыл бұрын

Hi Daniel! Thanks for your questions! There are a few people on the internet that have asked the same question (regarding the USB connection) on the eevblog forum (www.eevblog.com/forum/testgear/siglent-sds1104x-e-and-sds1204x-e-bode-plot-with-non-siglent-awg/50/) I suggest that you search around a little on the forum, it might hold some answers for you. It will definitely hold high res pictures of the PCB. Let me know if you succeeded in your quest to control the device over USB!

@danielnilsson2076

3 жыл бұрын

@@TimsElectronicsLab thanks for the reply. I have got stuck already at step 1 (buy Siglent DSO) due to flu-induced acute poverty, so this project will probably draw out in time.. but maybe the chinese have even better oscilloscopes to sell for the same price whenever/if I can get back on my feet economically speaking, I must admit that it feels a bit sad that a 4-channel DSO that can match the 70's Tektronix 2465 that could easily sync to 400MHz sine that I owned until 5 years ago and used mainly for hobbyist-level SMPS and class-D amplifier nerding is still so much out of reach even for many companies if you really want all 4 channels to support proper 350MHz bandwidth, I guess the ADC would need to work at 10-20Gs/s in order to catch things like diode cathode oscillations when switching a bit too hard..

@TimsElectronicsLab

3 жыл бұрын

Yeah these weird times hit everybody, still happy to read that your projects are continuing and I hope that you will be ok!

OMG