View Full Version : PS2 input from VPP
As the PS2 variants can deal with a quite high input voltages, then could it be used to get the 5V input from the main rail voltages?
I'm thinking something like an AMP2 with a trafo for the VPP and VNN and using PS2-Single for the 5V from VPP and ground. Would it work, would it have some negative sides to consider?
audiophool
30-Dec-09, 18:22
For the AMP2 and the TA3020 amps incl. Truepath and AMP7, which require separate V5 supplies, the V5 should be isolated from the VPP. That means a 4 terminal converter. Read more about it in the quote below. 41Hz does not yet have a 4 terminal DC-DC converter (the reason for this is likely expense as I explained in the quote). There are however plenty that are commercially available (also not cheap) - follow the thread link for a couple of examples. Since , most or all of these converters have a fair amount of ripple on the output, you would still need to follow the converter with a regulator.
Abelma,
If you read this post and are thoroughly confused by it, then I tend to agree with you. Moreover, I have to take credit with starting the confusion with the following:
To clarify what I mean, let me explain how to get the PS2 working to provide the auxiliary rails for Truepath. Per this picture, PS2 is a 3 terminal device and it is used for producing VN10. It can work with three terminals because the negative power rail and VN10 share a common negative rail, ie, VNN.
V5 on the other hand does not share a common negative rail with the positive power rail from which it is derived. Therefore, V5 is produced by PS2's brother, PS3. PS3 is a 4 terminal device because it has two separate "-" terminals and these are isolated from one another. This is an elegant circuit arrangement; PS2 and PS3 together omit the requirement for the second 12V+12VRMS taps on the transformer.
http://lh3.ggpht.com/zxeter/SGDNuirYS8I/AAAAAAAAC30/GrRS8ZV65hI/s800/PS2PS3.jpg
There are just a couple of issues with this arrangement:
PS3 does not exist
If PS3 did exist, it would likely be prohibitively expensive
Hence it will probably never exist
Regards,
Tim
There are some PS kits here (http://electronics.dantimax.dk/Kits/Power_supply_kits/index.html) which may be suitable for VN5 & VN10.
Simplest is to use a toroidal transformer, add a few windings of your own to create an isolated 12Vac and use PSU1-VR to do the rest.....
audiophool
01-Jan-10, 16:15
Simplest is to use a toroidal transformer, add a few windings of your own to create an isolated 12Vac and use PSU1-VR to do the rest.....
I think it depends on the application. If small size is your target then a DC-DC converter may be preferable.
audiophool
01-Jan-10, 16:30
There are plenty of DC-DC converters available but an important issue to consider with DC-DC converter is the size. If you are looking to make a compact amp then having a 2A V5 DC-DC converter will be a waste of space.
I have been looking for a decent sized, speced and priced isolated DC-DC converter for a while and have found one that I think is highly suitable. It's rated at 80mA which is just about ideal. Here's a pic. Real estate is similar to a Truepath.
48
Output ripple at 50mA (which is what the TA3020 draws) is less than 10mV. This is OK for general purpose amplification but for hifi it should be followed by a regulator.
I got some samples of these. If anyone is interested, let me know.
Looks like a Traco Power converter, only without sticker on top...
What's the price?
audiophool
01-Jan-10, 16:40
I looked at Traco but couldn't find anything that looks like the one that I posted. Can you post a link to the pic you are referring to?
Well I wasn't implying they are Traco power units. They just look like some I have used before, dark rectangular sealed units with PCB pins...
For example:
http://be.farnell.com/productimages/farnell/standard/1772350-40.jpg
http://uk.farnell.com/productimages/farnell/standard/42349776.jpg
audiophool
05-Jan-10, 14:50
There are plenty of DC-DC converters available but an important issue to consider with DC-DC converter is the size. If you are looking to make a compact amp then having a 2A V5 DC-DC converter will be a waste of space.
I have been looking for a decent sized, speced and priced isolated DC-DC converter for a while and have found one that I think is highly suitable. It's rated at 80mA which is just about ideal. Here's a pic. Real estate is similar to a Truepath.
48
The sample price is USD 6 plus USD 8 for shipping. I only have 8 pieces to sell so please let me know if you are interested.
Output ripple at 50mA (which is what the TA3020 draws) is less than 10mV. This is OK for general purpose amplification but for hifi it should be followed by a regulator.
I got some samples of these. If anyone is interested, let me know.
The sample price is USD 6 plus USD 8 for shipping. I only have 8 pieces so please let me know if you are interested.
It's a great size, quality and kind of converter. I just don't have an immediate need for it, normally I would just buy it, but the coming time is just too busy with other things....
I'll certainly keep it in mind!
TRACOPOWER - TMR 2-4811WI - CONVERTER, DC/DC, 2W, 5V/0.4A (http://se.farnell.com/tracopower/tmr-2-4811wi/converter-dc-dc-2w-5v-0-4a/dp/1284249), DC/DC Converters TMR 2WI Series, 2 Watt (http://www.farnell.com/datasheets/319840.pdf). 17€. A bit too expensive?
CONVERTER, DC/DC, 2W, 5V/0.4A
DC / DC Converter O/P Type:Single
No. of Outputs:1
Input Voltage:18V to 75V
Power Rating:2W
Output Voltage Fixed:5V
Output Current:400mA
Supply Voltage:48V
DC / DC Converter Case Style:SIP
Mounting Type:THT
Isolation voltage:1000V DC
SVHC:No SVHC (18-Jun-2010)
Efficiency:80%
Input Voltage Max:75V DC
Input Voltage Min:18V DC
Line Regulation:0.5%
Load Regulation:0.75%
Operating Temperature Max:+75°C
Output Ripple and Noise Voltage, pk-pk:50mV
Package / Case:SIL
Standard:EN 55022, class A and FCC, Level A
Temperature Operating Min:-40°C
Output Ripple and Noise Voltage, pk-pk:50mV
That's 1% ripple - too high for clean sound.
As audiophool mentioned, this would still need to be followed by a good linear VR, in which case you would have to get something like a 9V output.
That's 1% ripple - too high for clean sound.
As audiophool mentioned, this would still need to be followed by a good linear VR, in which case you would have to get something like a 9V output.
Ok, I will try to construct this thing (PS3). It will be my first serious design (soft starts don´t count :-) ).
Is 17€ too expensive for an isolated smps? Should I look for a cheaper one?
I found 2 chips at Farnell, both around 10€:
XP POWER - IU4809SA - CONVERTER, DC/DC, 2:1I/P, 2W, 9V (http://se.farnell.com/xp-power/iu4809sa/converter-dc-dc-2-1i-p-2w-9v/dp/1435430). 2 Watts IU Series (http://www.xppower.com/pdfs/SF_IU.pdf)
CONVERTER, DC/DC, 2:1I/P, 2W, 9V
DC / DC Converter O/P Type:Single
No. of Outputs:1
Input Voltage:36V to 72V
Power Rating:2W
Output Voltage Fixed:9V
Output Current:222mA
Supply Voltage:48V
DC / DC Converter Case Style:SIP
Mounting Type:THT
Isolation voltage:1000V
SVHC:No SVHC (18-Jun-2010)
External Depth:11.1mm
External Length / Height:21.85mm
External Width:9.2mm
Efficiency:72%
Input Voltage Max:72V
Input Voltage Min:36V
Line Regulation:0.5%
Load Regulation:1%
Off Load Current:6mA
Operating Temperature Max:85°C
Output Ripple and Noise Voltage, pk-pk:80mV
Temperature Operating Min:-40°C
MURATA POWER SOLUTIONS - NDL4809SC - CONVERTER, DC/DC, SIL, 2W, 9V (http://se.farnell.com/murata-power-solutions/ndl4809sc/converter-dc-dc-sil-2w-9v/dp/1021414). NDL Series Isolated 2W Wide Input Single Output DC/DC Converters (http://www.murata-ps.com/data/power/ncl/kdc_ndl.pdf)
CONVERTER, DC/DC, SIL, 2W, 9V
DC / DC Converter O/P Type:Single
No. of Outputs:1
Input Voltage:36V to 72V
Power Rating:2W
Output Voltage Fixed:9V
Output Current:222mA
Supply Voltage:48V
DC / DC Converter Case Style:SIP
Mounting Type:THT
Isolation voltage:1kV
SVHC:No SVHC (18-Jun-2010)
External Depth:21.8mm
External Length / Height:11.1mm
External Width:9.2mm
Flammability Rating:UL94V-0
Input Voltage:48V DC
Input Voltage Max:72V DC
Input Voltage Min:36V DC
Line Regulation:0.4%
Load Regulation:0.75%
Operating Temperature Max:85°C
Package / Case:SIP
Power Density:0.9W/cm³
Temperature Operating Min:-40°C
LM317, understanding and listening - July 2007, by Eric Juaneda (http://tech.juaneda.com/en/articles/lm317.html). With help like this I will not fail.
Gosh, what a semi-scientific piece of bullshit! LOL This has no technical foundation whatsoever, it's cool to listen to the sound of the end result, but without measurement results it has no reference at all...
Why doesn't he mention that in-line toroidal transformer before the 317?
Why doesn't he compare metal-film with carbon or handwound resistors?
Why doesn't he compare the built circuit on PCB made of glass-fiber, pertinax, whatever?
Why doesn't he compare copper wire with silver or gold?
Why doesn't he compare thin wires or even thick rods?
And is there a small or BIG heatsink attached to the 317?
Is the circuit near the window or near the wall? (never near the window!)
Are the circuit connections soldered or wire-wound?
Does he use RoHs, non-RoHs or silver solder?
So: totally incomplete and therefore useless.
And don't tell me he can hear the difference between the caps used in this 317 circuit. No way.
I think the main power grid is his problem or his personal grid (part above shoulders).
LM117/LM317A/LM317 (http://www.national.com/ds/LM/LM117.pdf)
LM117/LM317A/LM317 Package Options
PartNumber Suffix PackageOutput Current
LM117, LM317 K TO-3 1.5A
LM317A, LM317 T TO-220 1.5A
LM317 S TO-263 1.5A
LM317A, LM317 EMP SOT-223 1.0A
LM117, LM317A, LM317 H TO-39 0.5A
LM117 E LCC 0.5A
LM317A, LM317 MDT TO-252 0.5A
Which one to use?
17 Produktresultat hittades för “lm317” (http://se.farnell.com/jsp/search/browse.jsp?N=500014+1004522+567819+567529+567336+5 67238+5446473&Ntk=gensearch_001&Ntt=lm317&Ntx=mode+matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=sv_SE&catalogId=&prevNValues=500014+1004522+567819+567529+567336+56 7238&filtersHidden=false&appliedHidden=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN% 3D500014%2B1004522%26Ntk%3Dgensearch_001%26Ntt%3Dl m317%26Ntx%3Dmode%2Bmatchallpartial%26No%3D0%26get Results%3Dtrue%26appliedparametrics%3Dtrue%26local e%3Dsv_SE%26catalogId%3D%26prevNValues%3D500014%2B 1004522)
Manufacturers to choose from: NATIONAL SEMICONDUCTOR , ON SEMICONDUCTOR , STMICROELECTRONICS , FAIRCHILD SEMICONDUCTOR. National are more expensive than the others, are they better? Maybe I should ask Eric if he has made any comparison between manufacturers?
It's so much less magic and mystical than we give it credit for, sorry to blow the bubble...
The main thing about this is understanding what is important and what has influence.
One thing is noise, obviously, then load regulation, efficiency, current capability, price and maybe even dynamic properties, such as output impedance.
I'm pretty sure, even though it is just a hunch and even though this is a sensitive part of the class T amplifier circuits that when we go beyond a certain milestone in quality there is not much extra performance to be gained. Probably more on paper than in practise.
I also think Eric is the last person to ask something and expect a valuable answer from, with all due respect.
Try to find someone who has measured these different regulators and really knows what he/she is talking about....
P.S. It also depends much on the application by the way, for low current ultra low noise LT3080 seems like a very interesting chip to me...
LT3080 seems nice, but not easy+cheap to get I think.
Just get a LM317T (0-125' working temp, 1.5A, T=TO-220 case), is cheap (40p), very good, and if it gets hot, bolt a heatsink to the case.
Assume about 3V over the reg, so: 8V in, 5V out. You can cascade two..if you want. 11>8>5V
Get a couple of them, always handy!
For measuring all the parameters one would need good stuff + time. Just assume that Jan (317 is used on the amps here) has done his homework on it. Just go and do it.
You could use a small 78L05ACLP (low-power, 100mA, TO-92 case) for 20p, if you want/need cheap, it will suffice.
I'm sure I posted this link before, but can't find it right now, so here it is again:
http://www.diyaudio.com/forums/parts/127414-lm317-vs-7805-19-different-ics-compared.html
This compares fixed and adjustable VR's in a spreadsheet.
You will be surprised at the results (note there are multiple versions, so download the last one in the thread).
Here is a copy for those that are not members of that forum;
1042
Here is the priority list from this spreadsheet:
Priority List 1 Load Regulation 2 Line Regulation 3 Noise 4 Ripple Rejection
PS. I'm using the ON MC7805C for my AMP2 supply.
For those really on the ball, you can see (http://www.41hz.com/forums/showthread.php?3672-AMP2-component-build-sequence&p=31648#post31648)I have the SMD version soldered directly to the AGND plane at the edge of the PCB. I'll be feeding it with 12VDC from a small 10VA toroid, to keep the 2 GND's isolated, as my power toroids are potted and I can't add additional windings for this.
Very nice! So the LT3080 is good but X-pensive.
Will one hear the difference, that's what counts.
But please, put it in a separate thread and sticky it. Handy for look-up.
One can also use a standard LM723 of course....(can be in a 'can', = small).
Cheap too.
Came across the A723 too, for LED driving fun. max 8ch. of 12 LEDs.
Scratchy, thanks for that excel sheet. ON MC7805C is certainly a very tempting choice. It is so simple it is a bit boring actually.
The LT3080EST#PBF (http://se.farnell.com/linear-technology/lt3080est-pbf/ldo-reg-adj-1-1a-sot223-3/dp/1663553) is available in Sweden, and seems simple enough to solder. And of course it can be used for any voltage. Since the smps I found is about 10€, adding another 5€ is no big deal.
What about 10V Gate voltage (amp7), does it improve with more stable regulation? I was planning to use PS2 single for it.
What about 10V Gate voltage (amp7), does it improve with more stable regulation? I was planning to use PS2 single for it.
No it's totally uncritical. It would be pearls for the pigs....
Comments on this design please.
http://www.warp7.se/forum/files/thumbs/t_ps3_209.jpg
Full size image (http://www.warp7.se/forum/download.php?id=2207)
Nice find on the SMPS. Let me know how it works out.
I may try one in my next AMP2.
Comments on this design please.
Cset should be 500 nF. Time constant for starting will be 0,5 seconds. Is this ok?
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