Re: [Soekris] net5501 power supply input specifications
Hi, On 26 Feb 2012, at 12:24, Attila Kinali wrote: Hence i'd like to try another power supply but i don't have any 12V with 3A here, only a 16V. Unfortunately, there is no specification on what the net5501 can take as 12V suplly and whether these 12V are connected to the harddisk or PCI connectors. See http://soekris.com/products/net5501.html Power using external power supply is 6-25V DC, max 20 Watt, protected with TVS -- Bob Bishop r...@gid.co.uk ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] net5501 power supply input specifications
Attila Kinali att...@kinali.ch writes: I finally got around to measure the internal supply pins of my net5501 to see what exactly is going on. What i see are very very short (1us) drops of the 12 down that are larger than 1V. I guess the drops of the 3.3V and 5V supply that i see at the same time come from the 12V drop. But with the measurement equipment i have here and the lack of schmeatics, i cannot be sure. (it could be the other way as well) You could try putting a capacitor across the supply. 1us duration drops of more than 1V sound pretty suspicious though that something in the output filtering of your supply is messed up. It could also be that something is drawing outrageous currents at 3.3V which is stressing the regulator's current-handling ability and this is appearing upstream. But that seems less likely than a supply with something wrong (a bad output filtering cap, perhaps). Hence i'd like to try another power supply but i don't have any 12V with 3A here, only a 16V. Unfortunately, there is no specification on what the net5501 can take as 12V suplly and whether these 12V are connected to the harddisk or PCI connectors. (Someone else answered this already.) I have a hard time believing that a supply that will provide 12V 3A would have trouble. But I can believe that a particular supply labeled 12V 3A would not actually provide that reliably. Hence i would like to ask the following questions: * What is the exact specification of the 12 supply input? * Where are those 12V connected to? * Is there any stabilization or voltage limiter between the supply input and the harddisk and/or PCI connector? I'm not soekris, obviously, but my limited understanding is the net5501 only uses 5V and lower, actually the disk connector is a notebook disk, which is at most a 5V device same with PCI There is a regulator (perhaps a 7805) that brings 12V down to 5V. One can jumper to not use the regulator, and then the input has to be exactly 5V. I am using a net5501 with the input connected to a bunch of 12V lead acid batteries (in parallel), more or less a 12Ah, 4 7Ah and 4 4Ah, all on float charge and thus ranging from high 11s to 14.5V, typically 13.4V or so. This has worked fine. pgp2enjDACRD8.pgp Description: PGP signature ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] net5501 power supply input specifications
On Sun, 26 Feb 2012 13:13:48 + Bob Bishop r...@gid.co.uk wrote: Hi, On 26 Feb 2012, at 12:24, Attila Kinali wrote: Hence i'd like to try another power supply but i don't have any 12V with 3A here, only a 16V. Unfortunately, there is no specification on what the net5501 can take as 12V suplly and whether these 12V are connected to the harddisk or PCI connectors. See http://soekris.com/products/net5501.html Power using external power supply is 6-25V DC, max 20 Watt, protected with TVS Oops.. sorry.. overlooked this ^^' Thanks! Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] net5501 power supply input specifications
On Sun, 26 Feb 2012 09:28:53 -0500 Greg Troxel g...@work.lexort.com wrote: Attila Kinali att...@kinali.ch writes: I finally got around to measure the internal supply pins of my net5501 to see what exactly is going on. What i see are very very short (1us) drops of the 12 down that are larger than 1V. I guess the drops of the 3.3V and 5V supply that i see at the same time come from the 12V drop. But with the measurement equipment i have here and the lack of schmeatics, i cannot be sure. (it could be the other way as well) You could try putting a capacitor across the supply. 1us duration drops of more than 1V sound pretty suspicious though that something in the output filtering of your supply is messed up. Did that already. Put two 1000uF capacitors on J5 over 3.3V and 5V. It didn't help. Using my 16V supply i got rid of those deep spikes, now the 16V was stable. But the 3.3V showed still 50mV spikes. Unfortunately, with the equipment here i can not asses whether these spikes could lead to any trouble or not (using a low cost Tek 2024B isn't going to say much about such transients). The only fact i can be sure of ia that something is causing the net5501 crash under load. And i'd like to know what it is. It could also be that something is drawing outrageous currents at 3.3V which is stressing the regulator's current-handling ability and this is appearing upstream. But that seems less likely than a supply with something wrong (a bad output filtering cap, perhaps). Well, with no specs what the on board power supplies can handle, i have no way of telling whether something could be drawing too much current. The inductors look like they can take 1-2A each.. maybe more. I'm a little bit surprised, that i couldnt see any ceramic capacitors to block the HF noise. But i didn't look on the bottom, so... I have a hard time believing that a supply that will provide 12V 3A would have trouble. But I can believe that a particular supply labeled 12V 3A would not actually provide that reliably. Oh, that's quite easy to explain. Those power supplies sold by soekris (and many others) are cheap stuff. They are made to be cheap, not reliable. They can deliver nice continous power, but the moment you have load transients they behave badly. That's not the fault of soekris, it's just how power supplies are these days. And the only way to handle this is to make sure your system can cope with sudden power supply drops (unless you want to spend 3 to 10 times as much for the power supply). I'm not soekris, obviously, but my limited understanding is the net5501 only uses 5V and lower, actually Yes the disk connector is a notebook disk, which is at most a 5V device Nope. Notebook HDs still use 12V for the motor. same with PCI PCI supplies +3.3V, +5V, +12V and -12V. At least the net4501's manual states that the +12V and -12V supplies are not provieded, but there is no such statment for the 5501 (btw: that makes the PCI connector of the 4501 non-conformant to the PCI standard, but that's probably ok for most cards these days). There is a regulator (perhaps a 7805) that brings 12V down to 5V. One can jumper to not use the regulator, and then the input has to be exactly 5V. No, there are no linear regulators on the net5501 for the 5V and 3.3V. My guess is that the LM2642 that is halfway between the power socket and the big inductors provides those two power rails. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] net5501 power supply input specifications
the disk connector is a notebook disk, which is at most a 5V device Nope. Notebook HDs still use 12V for the motor. If so, it's generated onboard from 5V, bceause I've run laptop disks from connectors that don't supply anything but 5V and they've worked just fine. At least, assuming we're talking about ordinary IDE, which is what I think Soekrises use. SATA I know almost nothing about. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTMLmo...@rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] net5501 power supply input specifications
On 26 Feb 2012, at 15:26, Mouse mo...@rodents-montreal.org wrote: the disk connector is a notebook disk, which is at most a 5V device Nope. Notebook HDs still use 12V for the motor. If so, it's generated onboard from 5V, bceause I've run laptop disks from connectors that don't supply anything but 5V and they've worked just fine. At least, assuming we're talking about ordinary IDE, which is what I think Soekrises use. SATA I know almost nothing about. Notebook SATA disks use only +5V from the SATA power connector. 2.5 SAS disks require +12V also but you won't be using them with a 5501. I have yet to see a SATA disk use the +3.3V supply on the power connector as it's optional. Chris -- Chris Boot bo...@bootc.net ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] net5501 power supply input specifications
Hi Attila, Attila Kinali wrote: Hi, I finally got around to measure the internal supply pins of my net5501 to see what exactly is going on. What i see are very very short (1us) drops of the 12 down that are larger than 1V. I guess the drops of the 3.3V and 5V supply that i see at the same time come from the 12V drop. But with the measurement equipment i have here and the lack of schmeatics, i cannot be sure. (it could be the other way as well) The net5501 power input is decoupled with a low esr 330uF electrolytic capacitor and two 2.2uF ceramic capacitors. The 5V, 3.3V and CPU core regulators each have 1000 uF low esr electrolytic capacitors and plenty of large ceramic capacitors. So pulses like that are simply not possible, you might want to ensure you measure correctly, you can easily pick up noise from the inductors or other sources. Maybe with a 50 ohm probe directly over a capacitor. The inductors look like they can take 1-2A each.. The inductors are of course dimensioned to the need of the system, the 5V rail and 3.3V rail are both designed for 3.5A each, there should be at least 12W combined left for expansion Hence i'd like to try another power supply but i don't have any 12V with3A here, only a 16V. Unfortunately, there is no specification on what the net5501 can take as 12V suplly and whether these 12V are connected to the harddisk or PCI connectors. Hence i would like to ask the following questions: * What is the exact specification of the 12 supply input? As somebody already said, the official spec is 6-20V, absolute max is limited by the 26V TVS. * Where are those 12V connected to? The 12V circuit is special designed to enable use of a 3.5 HD If you supply 11-13V to the unit then a mosfet switch direct the power input directly to the 12V rail, you can then draw max 2A. Otherwise a dc-dc converter make 12V from 5V, with that you can draw max 0.5VA. The same converter make -12V for the PCI slot, at about 0.3A. The +12V rail goes to the HD power connector and the PCI slot. The principle is that you can then use a 3.5 HD if you supply 12V to the unit. Normal 2.5 drives don't use 12V. * Is there any stabilization or voltage limiter between the supply input and the harddisk and/or PCI connector? See above. And yes, this info should be in the manual. I do have a draft here that will be finished and released soon Best Regards, Soren Kristensen CEO Chief Engineer Soekris Engineering, Inc. ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] net5501 power supply input specifications
What i see are very very short (1us) drops of the 12 down that are larger than 1V. [...] The net5501 power input is decoupled with [...]. [...] So pulses like that are simply not possible, It occurs to me that perhaps the pulses are real and the underlying problem is that there's a hardware fault causing the decoupling to not work as well as it should. Anything from a broken etch run to a pick-and-place failure causing that particular board to not have all the decoupling it's supposed to could cause this - I'm speculating, of course, but such failures _do_ happen. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTMLmo...@rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] net5501 power supply input specifications
Hi Mouse, Mouse wrote: What i see are very very short (1us) drops of the 12 down that are larger than 1V. [...] The net5501 power input is decoupled with [...]. [...] So pulses like that are simply not possible, It occurs to me that perhaps the pulses are real and the underlying problem is that there's a hardware fault causing the decoupling to not work as well as it should. Anything from a broken etch run to a pick-and-place failure causing that particular board to not have all the decoupling it's supposed to could cause this - I'm speculating, of course, but such failures _do_ happen. Of course there can always be a defect, but as there are multiple caps it's not that likely I still believe that Attila is hunting for a nonexistent hardware issue, but if he wants to, he's welcome to get a replacement board, we do stand behind out products, now with full three years warranties. But I also know that from my own experience that if you just take a standard scope probe with the typical 10 cm ground lead, that 10 cm is very good at picking up unwanted pulses Best Regards, Soren Kristensen CEO Chief Engineer Soekris Engineering, Inc. ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] net5501 power supply input specifications
Moin, On Sun, 26 Feb 2012 09:20:22 -0800 Soren Kristensen so...@soekris.com wrote: The net5501 power input is decoupled with a low esr 330uF electrolytic capacitor and two 2.2uF ceramic capacitors. The 5V, 3.3V and CPU core regulators each have 1000 uF low esr electrolytic capacitors and plenty of large ceramic capacitors. So pulses like that are simply not possible, you might want to ensure you measure correctly, you can easily pick up noise from the inductors or other sources. Maybe with a 50 ohm probe directly over a capacitor. I wouldn't say impossible. But yes, you are right, it's most likely noise that i picked up (as i said, it's not HF equiment that i used). But then i wonder what's going on. The inductors look like they can take 1-2A each.. The inductors are of course dimensioned to the need of the system, the 5V rail and 3.3V rail are both designed for 3.5A each, there should be at least 12W combined left for expansion Hmm.. how is that 12W split? I doubt it's 6W on the 5V and 6W on the 3.3V? Is there a current sense resistor somewhere i could measure? I'm currently leaning towards that i pull too much power from one of the rails. Thanks for the various info! Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] net5501 power supply input specifications
On Sun, 26 Feb 2012 10:31:58 -0800 Soren Kristensen so...@soekris.com wrote: Of course there can always be a defect, but as there are multiple caps it's not that likely I still believe that Attila is hunting for a nonexistent hardware issue, but if he wants to, he's welcome to get a replacement board, we do stand behind out products, now with full three years warranties. Thanks for the offer. But i'd like to be reasonably sure that the board is defect before i send it back. Currently i'm still trying to figure out what's wrong. My guess were voltage drops on the power supplies. I could not measure them. I still wouldnt rule them out completely, but they are at least not of a magnitude that i could measure. Any hints what i could try? Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
