FRIWO 12 v medical grade PSU for Netgear GS108 switch

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Briain » 2018-11-05 15:25

Hi Lego

I can indeed confirm that the MPP15 Med 12V FRIWO suited for Netgear GS108 switches is indeed RS part number 472-8572.

There is also a version that doesn't come with the medical approval tag and I'm assured by a FRIWO distributor that the only technical difference is that they don't come with the green LED to indicate that they are switched on (and of course, don't come with medical use approval) but though I was told the circuit layout (as in the PCB) is the same I don't know if there are any minor specification differences for the components used inside them (I'd have to split the case of each type open and actually look inside for myself) and indeed I don't know whether the distributor really knows for sure that the PCB is the same, or whether that was just an assumption that they'd made.

I do have one of these non-med variants in use for another project, but it is a 5 V version and thus I can't directly compare them in terms of whether there's any difference to sound quality when used feeding a Netgear switch (which requires a 12 V version). The non-med ones are attractive in that they are slightly cheaper, but I just go for the med ones as to be honest, the price difference is not that large and for me, the green power LED on the med version is actually a very useful feature (I have a whole bank of FRIWO MPP15 and MPP30 units feeding various devices in my lounge, and yet another bank down in my 'comms room', and at times it's useful to be able to see - at a quick glance - that they're all powered on and working).

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Defender » 2018-11-05 22:59

thought the med ones are galvanically separated and have lower leakage current but thats just my thought

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Briain » 2018-11-07 15:44

Defender wrote:thought the med ones are galvanically separated and have lower leakage current but thats just my thought
Yes, that would be a logical assumption, but according to that distributor, other than the LED they are of an identical design (though the medical ones are guaranteed to meet the required medical standards and you're also paying for the certification process), but as I say, I have no idea on the validity of that information, so the only way to know would be to crack both types open and inspect the innards for differences (and from memory, the MPP15 cases are glued together). Anyhow, as I say the price difference is not very significant and in any case, I like having the green status LED, so other than the non-medical one that I'm using to power both my VoIP phone and a Raspberry Pi, all the others I have are the medical grade chaps.

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Briain » 2018-11-07 16:12

Defender wrote:Hi all need to put some live into the FRIWO discussion as I made a strange experience.
Music Lover has asked this question before but it was not answered.
How to make sure the Friwo is on the right phase.

For most part of Europe you have two options/positions to put the Friwo into the power
outlet.
In my house phase is always at the left side and neutral on the right side of the outlet.
For me the FRIWO works/sounds the best when it gets the phase on the right side looking from top (so in my situation the output cable is facing upwards to make the FRIWO get the phase in the right way.
However that’s for me - interesting enough there is one more musical option ... for me by a good margin.
The RS FRIWOs come with several DC power plugs and also several mains connector 'sledges' but you can also get an IEC320 C7 mains sledge (so that would be useful to UK customers who wish to try reversing the connection).
IEC320C7.JPG
IEC 320 type C7
IEC320C7.JPG (138.1 KiB) Viewed 4292 times
Unfortunately, RS do not stock these sledges, so you'd have to get them directly from the FRIWO sales portal (and the postage costs are prohibitive). I managed to scrounge two of them as part of me tendering for a job which would have required me to supply a whole bunch of FRIWOs at an industrial site (where 'wall wart' format supplies were not acceptable to the customer). Probably the most economical way to procure them would be to round up a bunch of folks who want them, have someone order the required quantity, then split the postage across the batch (and add local postage to each one sent). I guess another way might be for several people to individually ask RS and that might prompt them into stocking them (I'm not sure how many queries it takes to trigger RS into stocking items, though).

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Paaf » 2018-11-12 05:20

Did someone try the FRIWO with the QNAP TS-109 which also happens to use 12V?

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by phino » 2018-11-13 09:35

Paaf wrote:
2018-11-12 05:20
Did someone try the FRIWO with the QNAP TS-109 which also happens to use 12V?
I'd be really wary of that. The MPP15 is 15 watts, the original 109 takes 14.3 - and Ithink that might be the rating without a disc installed. It and the subsequent versions of the 109 were supplied wifh a 36 watt power supply. So, I wouldn't risk it myself, you could damage either the nas or the psu - and in the worst case possibly start a fire :(
I'd try a higher rated Friwo.

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Lego » 2018-11-13 17:23

Briain wrote:
2018-11-05 15:25
Hi Lego

I can indeed confirm that the MPP15 Med 12V FRIWO suited for Netgear GS108 switches is indeed RS part number 472-8572.

There is also a version that doesn't come with the medical approval tag and I'm assured by a FRIWO distributor that the only technical difference is that they don't come with the green LED to indicate that they are switched on (and of course, don't come with medical use approval) but though I was told the circuit layout (as in the PCB) is the same I don't know if there are any minor specification differences for the components used inside them (I'd have to split the case of each type open and actually look inside for myself) and indeed I don't know whether the distributor really knows for sure that the PCB is the same, or whether that was just an assumption that they'd made.

I do have one of these non-med variants in use for another project, but it is a 5 V version and thus I can't directly compare them in terms of whether there's any difference to sound quality when used feeding a Netgear switch (which requires a 12 V version). The non-med ones are attractive in that they are slightly cheaper, but I just go for the med ones as to be honest, the price difference is not that large and for me, the green power LED on the med version is actually a very useful feature (I have a whole bank of FRIWO MPP15 and MPP30 units feeding various devices in my lounge, and yet another bank down in my 'comms room', and at times it's useful to be able to see - at a quick glance - that they're all powered on and working).

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Defender » 2018-11-13 17:34

Hey Paaf,
there are of course FRIWO replacements also for the brick type power supply the TS-109 has. I have replaced mine for the TS119 I have. I am not sure about the rating for your brick wall type for the TS-109 - you need to check if the DT50Medizin (3800mA) is enough or if you need to have the DT80Medizin(5500mA).
From the specs the DT80Medizin has a higher leakage current (bad) - not sure if that makes a difference.

Mine is the DT80.

Now your next question might be does it make a difference in sound. I dont know - I have put it into my system while changing a lot of other things so I dont know how it contributed. All I know it is also making a diffence which pin gets the live wire/phase. In my case the life pin of the 2pole connector need to be on the left side of the brick power connector.

For me it was more important to possibly reduce the amount of radiation and I invested the small amount of money to have better sleep and not have to worry.

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Paaf » 2018-11-14 02:18

Good thinking! I forgot to check the mA specs.. doh!

I now find many FRIWO 12V options on the local shop (Elfa) and some of them are even the brick type which I would prefer compared to the MPP15 design. On the other hand, it would be a gamble since AFAIK no one here tried them yet.

Maybe I can call the shop and ask if PSU model this or that is musical... :)

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by phino » 2018-11-14 20:48

Paaf wrote:
2018-11-14 02:18
Good thinking! I forgot to check the mA specs.. doh!

I now find many FRIWO 12V options on the local shop (Elfa) and some of them are even the brick type which I would prefer compared to the MPP15 design. On the other hand, it would be a gamble since AFAIK no one here tried them yet.

Maybe I can call the shop and ask if PSU model this or that is musical... :)
They're not exactly cheap, compared to the rubbish that gets supplied with kit. If it's a shop, can you ask them if you can borrow one for a couple of days? If you don't ask.... :)

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Briain » 2018-11-15 16:05

Hi

I'm using an assortment of MPP15 and MPP30 (it's 30 Watts big brother). From a long wave, medium wave and short wave radio interference perspective, both the MPP15 and MPP30 are equally excellent and don't pump lots of noise back into the mains wiring (which can then act as an antenna, thus creating radio noise; a portable AM receiver is one of the tools I use when assessing power 'wall wart' type power supplies). Looking at the other end of them (the DC output side) and for a similar load (from memory, it was about 7 Watts) the MPP had less ripple (which is good) but it did have some switching spikes visible (though still far, far less noise than the other wall wart type supplies that I tested). Surprisingly, feeding the DC output cable through a ferrite ring (only about 14 turns) was enough to completely remove them.

I'm now using a 12V MPP30 (with the ferrite ring) to power my miniDSP (which does the roll off and time alignment for my 345 sub) and another MPP30 for my home theatre PC (a mini fan-less one that consumes under 30 Watts when working hard) and yet another MPP30 for my 'router' (another fan-less mini PC running Sophos UTM 9). Below shows one of the MPP30s with its DC output cable fed through a 40 mm ferrite ring:
Ferrite_SophosPSU.JPG
Ferrite ring on MPP30 output
Ferrite_SophosPSU.JPG (85.86 KiB) Viewed 4087 times
The above only has 12 turns as at 40 mm, the ring is quite small (it was one that I happened to have in stock) but on the other MPP30s, I've used a 50 mm rings so I can get more turns through tem (RS part 212-0881 @ https://uk.rs-online.com/web/p/ferrite-rings/2120881/).

There is a well known trick whereby after wrapping the first half with your turns, you can cross over the wire and start wrapping the other half. This reduces capacitive coupling between the input and output wires. A picture being worth a thousand words, below shows the technique more clearly than does the picture.
Ferrite_Winding_LCC.jpg
Best winding technique
Ferrite_Winding_LCC.jpg (138.95 KiB) Viewed 4087 times
The power supplies that come with Qnaps are of the laptop 'power brick' format and these tend to be far better than your standard 'wall wart' supplies. Wall wart supplies are typically designed to be bundled with cheap devices, so not only are they cost engineered (to make them as cheap as possible) but as well as the high cost of fitting a decent mains filter, they're also physically quite large, so with the 'power bricks' being designed for the laptop market, the cost is not such an issue and the size facilitates fitting a larger mains filter, so in general, they tend to be reasonably okay (though that is just a 'rule of thumb') so I'd not worry too much about the Qnap supply as it's probably quite a reasonably high quality one.

Also worth noting that inside many of the products which are fed by these external 12 V supplies will be buck and flyback regulators (to provide +5 V and -12 V, respectively). I looked inside my previous switch (a D-Link) and then looked up the data sheet for the on-board buck regulator. It showed several typical circuit diagrams (for the various types of things it can be used to do) and I noted that the diagrams showed optional output filter components. Of course, one of these optional components is a small inductor and none of the devices that I've ever looked at included one (the manufacturers would see it as simply being a waste of money in a £30 switch, for example) so that is another area I eventually plan to look into. It wouldn't be easy to modify something like a small switch, but with it being a £30 device, I wouldn't be too concerned about breaking it.

Of course, I'm now using a fancy 24 port Cisco managed switch (needed as I run several VLANs) but I've not yet looked inside that to see what the power arrangements are (though it is on my 'to do' list) and though it would likely be easy enough to change it's internal 12 V supply (if that's even necessary; it might be quite a nice PSU board as it isn't a low budget product) but given the high cost of these switches, I'll maybe have to think twice about attempting to add additional filtration to the buck regulator stage on the main circuit board (though I'll not know until poking about inside to see how it is all laid out) but if it looks possible, I'd like to give it a shot (though I'd then need to find another Cisco switch to compare them, so that could be the trickiest part). :)

Bri

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Paaf » 2019-01-04 15:05

Which FRIWO DC-connector is right for the Netgear switch?

There is a range of options like STA1227, STA1229, STA1230, STA2556 etc. They all look very similar to me in a catalog. The exact size should help me find the right one.

I can't find the info in the GS105/8 specs/datasheets.

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Defender » 2019-01-04 15:22

I am to 90% sure its the plug with the following measures:
Diameter in 2.1mm
Diameter out 5.5mm
Length 9.5mm


Only not 100% sure measure is the inner diameter but you can test it with a drill (the side which usually gets into the drill chuck) of 2.5mm on the Netgear Power Supply (make sure you disconnect it from power before) if you get it into the plug order the 2.5mm/5.5mm/9.5mm if not order the 2.1mm/5.5mm/9.5mm plug.

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by tokenbrit » 2019-01-05 00:14

I thought the MPP15 came with a few of the most common connectors - it did for me and one of them fit just fine. Be sure to check the Netgear PSU to confirm the polarity.

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Paaf » 2019-01-06 18:00

Defender wrote:
2019-01-04 15:22
you can test it with a drill (the side which usually gets into the drill chuck) of 2.5mm
I unfortunately I do not have any 2.5mm drill, the smallest is 3mm. But I found an old headset with the tiny plug which I think is 2.5mm? It does not fit (as you thought with the probability of 90% :).
Last edited by Paaf on 2019-01-06 18:07, edited 1 time in total.

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Paaf » 2019-01-06 18:01

tokenbrit wrote:
2019-01-05 00:14
I thought the MPP15 came with a few of the most common connectors - it did for me and one of them fit just fine. Be sure to check the Netgear PSU to confirm the polarity.
It does not in the shop where I ordered it, and good thinking to check the polarity!

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Paaf » 2019-01-06 21:36

According to the data sheet I need the STA1228 which is 5.5 2.1 9.5:
https://www.elfa.se/Web/Downloads/he/et ... asheet.pdf

However, it seems this project of mine is jinxed: in the catalogue at Elfa.se (where I bought the psu itself) they have STA1227 and STA1229, but not the STA1228. Doh. :)

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Defender » 2019-01-07 10:10

you can check Conrad.se if they have it as I got mine from CONRAD.de
another chance is to order from Friwo.de directly they send to Europe but the delivery costs might make it an expensive buy.
RS Components should also have it.

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Paaf » 2019-01-07 19:17

Thank you!

Friwo-shop.de charges €14:90 postage. Conrad.de isn't clear about sending to other countries than Germany or not, but likely the postage would be similar to Friwo-shop. Conrad.se doesn't seem to have it.

Easiest now is probably to allow Elfa some days to help me. I haven't gotten excellent service from them before, but hopefully they will surprise me this time. :)

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by fatjulio » 2019-08-22 12:47

I'm looking at getting a Friwo power supply for my GS108T. The MPP15 seems to be the recommended one. I've noticed that the desktop version DT50 has more current for less money. Does anyone know if the brick designs are better or worse than the wall worts?

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by Defender » 2019-08-26 15:37

its recommended to use the MPP15 in this case - technical data doesnt say much about musicality and the MPP15 got good feedback for musicality

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Re: FRIWO 12 v medical grade PSU for Netgear GS108 switch

Post by linesrg » 2019-10-06 18:21

Good Evening All,

I realise this is an 'old' thread now but did anybody try using a superregulator type supply and get away from switch mode completely?

Regards

Richard
LP12 Radikal/Keel/Urika II/Ekos/Krystal, Akurate DS/3, NAC-52/SNAXO c/w SC's, 3 x NAP250 + Isobariks

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