Author Topic: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator  (Read 315992 times)

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Offline cybermaus

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #850 on: February 25, 2018, 06:55:25 pm »
Choices, choices.....

I do feel that going from any wave to CMOS should avoid going over 3.3 (5) or below 0, unless you specifically set that.
But I also feel that having set Vpp and offset, and then walking from Sine to Triangle or so, should not loose your values because you happened to walk past CMOS

To be honest, I think apart from your idea to set an optional per channel DUT voltage safety window, when walking through the waveforms they should not immediately apply, but only after you confirm. So you can go from one wave to the other, without generating all the waveforms in-between. This is unlike walking through frequencies, which of course should immediately apply.


In fact, in the hope that FeelTech would pick it up, a good while back I already mentioned that pressing the Wave button is auto-advancing, which is wrong anyway:
Right now, if I am on Square, and I want to go to Sine (one to the left), I always first have to go to CMOS (one to the right) and then go 2 back. Just plain silly.
 

Offline paulca

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #851 on: February 25, 2018, 07:17:49 pm »
Absolutely no need to be intimidated by the numbers when calculating power supplies Paulca.
Take your winding voltage ,multiply it by 1.4 ,now from this you have to subtract the losses across the diodes in the bridge ,then you'll still have to allow at least a few volts extra so that whatever regulator you have can function effectively without dropouts .
Google Duncans PSUd 2.

Thank you.  The "time 1.4" thing leads me to ask "why 1.4" which leads to a rabbit hole.  But... I have seen it used enough without caveat that maybe I should just trust it.

I was also considering the drop on the linear regulators and thus aiming high for +-15V to provide +-12V as +-13VAC are hard to find.  Also once you factor in the drop across the recifier 13V will become 12.3 volts quickly. 

Different engineering, but in software when I can't calculate (or don't want to calculate) exact values, I just double the estimates to provide a suitable margin.

Going for +-15V for a +-12 rail through a transformer is not quite doubling, but lets not split hairs. :)

Quote
Best o luck.

You know in an odd way that makes a difference to a post.  I might have had half (+50% engineering grace) a bottle of wine, but for me it suggests you took to the time to actually care that I have luck and you weren't just show boating your knowledge.

The point of this post, having too much wine asides...

It's the VA rating that bothers me.  When a transformer says it has a rating of 6VA,  what does this actually mean in real terms?  Especially if you want to run a given DC load off it?
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline fremen67

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #852 on: February 25, 2018, 07:57:46 pm »
Choices, choices.....

I do feel that going from any wave to CMOS should avoid going over 3.3 (5) or below 0, unless you specifically set that.
But I also feel that having set Vpp and offset, and then walking from Sine to Triangle or so, should not loose your values because you happened to walk past CMOS

To be honest, I think apart from your idea to set an optional per channel DUT voltage safety window, when walking through the waveforms they should not immediately apply, but only after you confirm. So you can go from one wave to the other, without generating all the waveforms in-between. This is unlike walking through frequencies, which of course should immediately apply.
So then we could go for a mix: Protection via min/max voltage (to be set before connecting the DUT...) and then anyway sending null offset (without loosing the value) when in CMOS.
But once activated,  over range voltage protection should not depend on the selected wave. Once your DUT is connected it should be protected whatever you could do.
In fact, in the hope that FeelTech would pick it up, a good while back I already mentioned that pressing the Wave button is auto-advancing, which is wrong anyway:
Right now, if I am on Square, and I want to go to Sine (one to the left), I always first have to go to CMOS (one to the right) and then go 2 back. Just plain silly.
Yes indeed. You can imagine the following:
- 1 push on wave button: highlight wave selection (selection mode)
- another push on wave button: cancel selection mode
When in selection mode:
Turn rotary knob to go through waves without modifying the current one (wave plot having another colour to show selection mode active)
Confirm your choice by pushing the rotary knob..
I'm a machine! And I can know much more! I can experience so much more. But I'm trapped in this absurd body!
 

Offline DerKammi

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #853 on: February 25, 2018, 08:17:57 pm »
Tiny update from my side
Better each time :-+

May I suggest these modifications?

W16: DC_AMPL_CH2_OFFSET
W3: DC_AMPL_CH2_GAIN

W26: DC_AMPL_CH1_OFFSET
W5: DC_AMPL_CH1_GAIN

That is why I post the small updates. Consider it done 😁
 

Offline cybermaus

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #854 on: February 25, 2018, 08:37:39 pm »
Yes indeed. You can imagine the following:
- 1 push on wave button: highlight wave selection (selection mode)
- another push on wave button: cancel selection mode
When in selection mode:
Turn rotary knob to go through waves without modifying the current one (wave plot having another colour to show selection mode active)
Confirm your choice by pushing the rotary knob..

Exactly. For the Wave.

For others, like frequency, a small variant:

- 1 push on freq button: highlight freq selection (selection-follow mode)
- another push on freq button: different color highlight (selection-confirm mode)
- yet another push on freq button: cancel selection mode, no more highlight.

When in selection-follow mode:
- Turn rotary knob to go through frequencies *with* modifying the frequency,
- As the frequency is set automatically, it stays the normal color

When in selection-confirm mode:
- Turn rotary knob to go through frequencies *without* modifying the current one
- As the frequency is not set, it stays the special UNSET color
- Confirm your choice by pushing the rotary knob, now color returns to the SET color, until you turn the rotary again.
- Canceling your choice (by pressing freq button again, while color is the UNSET color, displays the original frequency and non-highlighted color


So while we have 2 modes for frequency (follow and confirm) and analogue the wave has only one mode (confirm), I would argue for frequency the follow mode is the first one, whereas for wave the confirm mode is the first (and actually only) one.

Amplitude and Offset may also have similar follow and confirm modes, so you can either jump from one to the other, or walk to it.
« Last Edit: February 25, 2018, 08:39:53 pm by cybermaus »
 

Offline soundtec

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #855 on: February 25, 2018, 08:40:22 pm »
Thanks for that Paulca ,
The 1.4 thing is just a rule of thumb ,different factors like load regulation of the transformer  and actual current vs rated current all add variables into the equation . When speccing a transformer for a given job ,you have to not only calculate the output current ,but also add in the ac current handled by the smoothing capacitors too ,typically over speccing your transformer by 50% compared to the load current is a good starting point , as we have seen the power consumption of the FY6600 is about 10 watts max , a 20 watt rated core here will run nice and cool  ,where a lower VA rated component might run hot and because its at the edge of its capabillity magnetic leakage/interference and noise  starts to become a bigger issue also . The great thing about the old style linear supply is that if its nicely over specced for the job you can be sure of a very long and trouble free life , switchers tend to have a limited lifespan ,and once capacitor values stray beyond a certain margin catastrophic failure isnt far off .
 

Offline DaveR

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #856 on: February 25, 2018, 09:06:58 pm »

I don't order from Mouser, but RS Components or for a sizable order Farnell.  RS have free shipping and no handling charge for any size of order including a single 0.1p resistor technically.  Though you would feel like a bit of a dick doing that to them.


I didn't realise RS had free postage on online orders now, but I've just checked and you're right - although I'm sure when I ordered some stuff from them a few months ago I had to add a load of basket fillers to take the value over £25 to get the free delivery.  I've also just found that they've got a branch nearby, which could be handy.

I was quite interested in Insatman's D75J TCXO from Digikey until I saw the price: £8 for the pinhead sized component (not too bad when you consider what it does), and £12 for the postage!  But I could have it delivered free if I bought another £20+ worth of basket fillers to go with it.  I think I'll just live with the 4ppm error I've got. (And it's stable within 10 minutes.)

Dave
« Last Edit: February 28, 2018, 01:50:02 am by DaveR »
 

Offline Chris56000

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #857 on: February 25, 2018, 09:09:28 pm »
Hi!

Trying to find a good economically priced small transformer with two suitable secondaries small enough to go in the FY6600's case is like trying to find a needle in a haystack with eBay's useless search engine, but I located this one - it's a low-profile R-core transformer of 30VA rating, the two 9V secondary windings can be connected in parallel IF you are careful of course to give 9V @ 1.4A. Best of all, it has dual-primary 115/230V for world-wide application plus an inter-winding screen as well!

I've ordered one to try in mine!

https://www.ebay.co.uk/itm/115V-230V-30W-High-Quality-Audio-R-Core-Transformer-15V-15V-9V-9V-For-Preamp/131588122667?hash=item1ea343682b:g:PfgAAOSwBadTpmyy

Opinions please?

Chris Williams

PS!

Suggestion for 5V linear supply to use with above transformer:-

https://www.ebay.co.uk/itm/L7805-Step-Down-7-5V-35V-to-5V-DIY-Kit-Power-Supply-Module-new-UK-seller/271656192244?hash=item3f3ff888f4:g:2lAAAOSw1XdUV6q1

Suggestion for ±15V dual linear PSU module for use with above transformer:-

https://www.ebay.co.uk/itm/AC-DC-Voltage-Regulator-LM317-LM337-Adjustable-Filtering-Power-Supply-DIY-Kits/302371834320?hash=item4666c409d0:m:m3whryg5vfLibDo-QTtc79w

NB!

The links I've provided refer to kit items, to facilitate substitution of higher quality electrolytic capacitors in the designs, etc. I believe the maximum current ratings of these kits are suitable for adequately powering the FY6600's electronics, but please feel free to correct me if I'm wrong!

« Last Edit: February 25, 2018, 09:59:27 pm by Chris56000 »
It's an enigma that's what it is!! This thing's not fixed because it doesn't want to be fixed!!
 

Offline DerKammi

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #858 on: February 25, 2018, 09:16:44 pm »
Another quick update before going to bed.
 
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Offline DaveR

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #859 on: February 25, 2018, 10:11:17 pm »

Trying to find a good economically priced small transformer with two suitable secondaries small enough to go in the FY6600's case is like trying to find a needle in a haystack with eBay's useless search engine, but I located this one - it's a low-profile R-core transformer of 30VA rating, the two 9V secondary windings can be connected in parallel IF you are careful of course to give 9V @ 1.4A. Best of all, it has an inter-winding screen as well!


That's the transformer I used, Chris - it's light, cool and, as far as I can tell, very low noise (as r-cores are supposed to be).  I only used one 9v secondary, which is more than enough for the job, as I thought I'd keep the second one free to drive a fan if it needed it (it doesn't).

The bipolar board is also the one I used; it's got nice big tits smoothing capacitors on it, which is a good thing, and it produces very little heat.  It's bigger than it looks in the picture, but still fits in the case ok.

As you've got an adjustable 12 - 15v supply, and as you can't guarantee that the 5v module will actually deliver 5v, why not allow yourself some leeway and get the LM317 version for a few pence extra, then you can dial in whatever exact voltage you want?  (I set mine to 5.1v to give a little extra headroom for the regulators on the main board to play with).  I didn't use the 5k pot that comes with it,  but mounted a multiturn trimpot on a piece of veroboard and put that in its place.  I also left off the switch, and the big spring connectors (I used a screw connector block instead).

The transformer and modules are all fixed with nylon spacers and screws, and I fitted a switched earth wire to the 0v line on the bipolar board so that the whole thing can be either earthed or floating.

Enjoy yourself putting it all together!

Dave
« Last Edit: February 25, 2018, 11:16:34 pm by DaveR »
 

Offline Chris56000

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #860 on: February 25, 2018, 10:40:21 pm »
Hi!

Quote
As you've got an adjustable 12 - 15v supply, and as you can't guarantee that the 5v module will actually deliver 5v, why not allow yourself some leeway and get the LM317 version for a few pence extra, then you can dial in whatever exact voltage you want?  (I set mine to 5.1v to give a little extra headroom for the regulators on the main board to play with).  I didn't use the 5k pot that comes with it,  but mounted a multiturn trimpot on a piece of veroboard and put that in its place.  I also left off the switch, and the big spring connectors (I used a screw connector block instead).

Thanks for your tip Dave - I do industrials at work where I routinely have to fit new 7805s and the ones my employer buys are literally pot-luck as to how accurate they are!

As the FY6600 is only known to take 400-500mA @ 5V, me thinks this one is perfect, not needing anything anything omitting, chucking-out or the board altering! I've ordered one!

https://www.ebay.co.uk/itm/LM317-Adjustable-Power-Supply-Board-With-Rectified-AC-DC-Input-DIY-Kit/401482358932?epid=21010444566&hash=item5d7a36a094:g:2NsAAOSwaLdaaDEO

Chris Williams




It's an enigma that's what it is!! This thing's not fixed because it doesn't want to be fixed!!
 

Offline DaveR

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #861 on: February 25, 2018, 11:07:28 pm »
That's just the job, Chris.  How have I not come across that one before?  (I've now ordered a couple for the bits box.)

Regards,
Dave
 

Offline soundtec

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #862 on: February 26, 2018, 01:52:45 am »
I tried out Fremens tweeked software earlier ,thats really handy that it runs seamlessly with the original , even the small changes to the look of it so far is a big improvement over the original ,the white text on black/grey backround looks great ,and the bigger waveform window helps too .

Tomorrow I might try making a steel screening plate to sheild the main boards from any radiated noise from the psu , I might also ask a friend with serious test gear and sixty years electronics experience to run through the unit and pass on any suggestions he might have for improvements .

Apart from non destructively fitting the other psu I had ,I havent done anything yet that voids my warranty , Id prefer to get a few hours up on it and do proper functional tests before filing and drilling ,just in case it has to go back.
 

Offline DaveR

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #863 on: February 26, 2018, 02:20:00 am »
I tried out Fremens tweeked software earlier ,thats really handy that it runs seamlessly with the original , even the small changes to the look of it so far is a big improvement over the original ,the white text on black/grey backround looks great ,and the bigger waveform window helps too .


I agree.  I gave the software a run out as well (Control window, anyway), and it's a big improvement in layout and appearance compared with the original.  All the functions work as they were intended - only the offset display and sliders need more work, but, as fremen said, they aren't a priority at the moment.  Thanks again for what you are doing, fremen67!
 

Offline Propretor

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #864 on: February 26, 2018, 02:27:50 pm »
Hi!
Is there a difference in hardware from the models FeelTech FY6600 60MHz and FY6600 30MHz?
Or the difference is only in FW?
Is there a problem with the FW version? I correctly understood that versions 3.0 and 3.1 are bad, and 2.9 or 3.2 are successful?
 

Offline soundtec

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #865 on: February 26, 2018, 03:23:28 pm »
Hi Prop,
Welcome aboard,

As far as we know the lower end units have the limitations imposed in the front panel firmware ,and due to the dedication of the talented contributors here we're well on the way to jailbreaking it.
The current firmware revisions on offer seem to be 3.2 and 3.21 ,and so far no reports of problems with these .
I ordered my unit mid January and received V3.2 ,the ebay seller was called 'echoii_shop' ,another contributor got V3.21 but you need to scan back through the posts to find the suppliers name. For me, the good spirited nature in which people have given their time and energy to this project made me want to get involved.
 
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Offline paulca

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #866 on: February 26, 2018, 04:20:57 pm »
Well, buying that transformer from Germany has turned into a bit of a farce.  He added 8.00Euro shipping, but switched the payment method to "Money transfer".  I hit "Transfer" and confusingly it just went to a page with nothing of use on it.  I figured from the Google translated german that I had to hit this to get the sellers bank details.

I tried to use Western Union, who were going to charge me something like £6!  But they would not accept my credit card.

So I tried my bank and it would not let me send the money without knowing the exact name and address of both the receiver and his bank.

So I'm now trying to cancel the order.
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline paulca

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #867 on: February 26, 2018, 05:02:10 pm »
The links I've provided refer to kit items, to facilitate substitution of higher quality electrolytic capacitors in the designs, etc. I believe the maximum current ratings of these kits are suitable for adequately powering the FY6600's electronics, but please feel free to correct me if I'm wrong!

I have ordered the same kits.

Is it worth replacing the caps or just run with the ones in it?
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline DerKammi

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #868 on: February 26, 2018, 08:22:00 pm »
@Fremen67: Just had a go with your PC software and it is working very nice already. Major thanks to all the work done so far.

Cannot image the work you are going to do on the firmware of the generator. Very promising.

 

Offline Propretor

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #869 on: February 26, 2018, 08:22:29 pm »
Thanks for the answer soundtec. If I correctly understood you, the chips are used the same and the difference is only in the firmware?
« Last Edit: February 26, 2018, 08:25:12 pm by Propretor »
 

Offline Propretor

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #870 on: February 26, 2018, 08:27:59 pm »
Colleagues, I do not see the point of changing the switching power supply in the generator. After it there are linear stabilizers. The only thing that makes sense is the ferrite rings on the cable that connects the power supply to the main board and place the power supply inside the metal screen. All the rest does not make sense.
 

Offline DaveR

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #871 on: February 26, 2018, 09:47:21 pm »
Colleagues, I do not see the point of changing the switching power supply in the generator. After it there are linear stabilizers. The only thing that makes sense is the ferrite rings on the cable that connects the power supply to the main board and place the power supply inside the metal screen. All the rest does not make sense.

Thanks for your views, but the power supply was built down to a price, not up to a quality.  Never underestimate the inclination of inquisitive meddlers to obtain pleasure and satisfaction from simply doing the work, whether it makes sense or not.  Some of us do it simply because we can, others because they want to improve their knowledge and skills.

Regards,
Dave
« Last Edit: February 26, 2018, 09:54:00 pm by DaveR »
 

Offline soundtec

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #872 on: February 26, 2018, 09:54:25 pm »
Yeah thats my reading of it anyway Propretor,  theres others in here who would be able to explain a lot more precisely the differences between  the models. Its looking like we may have the abillity to link to the generator board itself using a pre programmed chip very similar to what exists in the front panel already ,and thats opening up a few options in terms of the user interface etc,new software and extending the functionality of the 6600.

As for the power supply , It seems the output op-amps at least run directly off the +/- 12 volt rails , I have measured some small dragging down on the 5 volt rail as you increase the amplitude of the output signal ,that means things are modulating to some degree at least . The primary reason people want to include a transformer is for the isolation it provides ,there was a concern with leakage from the standard switching arrangement due to lack of mains grounding also.
I kind of have my options open as far as different power supply arrangements, I'm  running off a switcher for now ,but not the original feeltech part. I might try adding a seperate 5 volt switching rail  and a 1:1 mains transformer , but I also have the right transformers and regulators to do a linear supply later on if I choose too .

There's downsides to both , one plus of the linear approach is that a well designed system could give faultless performance for 30 years or more , the switcher psu lifespan ,its an unknown . The switcher potentially has high frequency garbage on the line,the transformer  could cause magnetic interference ,extra screening between power supply and the other boards would be a good plan in any case .
 

Offline Propretor

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #873 on: February 27, 2018, 01:30:13 pm »
I understand what you're talking about Dave. I myself am so. But in this case, I will confine myself to eliminating the Y capacitor in the power supply and installing the ferrite rings.
I'm worried about something else. After reading this forum (and I do not know English well, I apologize) I became frightened. There were reports that with some versions of the firmware the generator was dying. At the same time it is irretrievable. I would like to avoid this.
 



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