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swag72

Never underestimate the importance of power

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A couple of folks on here have shared different parts of my 'power journey' - I thank them for sticking through my moaning and issues and especially @RayD who was super helpful and made many recommendations that have worked! And made me up a cable too :) 

The reason for this thread is that I would never have believed that electricity could cause so many problems and it's something that people should perhaps be aware of when they are facing problems and need to have some ideas as to where to turn to.

Here's what I need to power......

1) Eagle2 PC - This in turn powers 2x camera's and 3x Dew straps. There are also 8 USB ports, 4 of which are switch on and 'off-able'
2) EQ8
3) 2 x Lakeside focusers

I have until recently plugged the Eagle2 into the mains power supply, the mount has it's own power pack and the Lakesides have gone into that as well. Over the last 2-3 months things have started to go very wrong, predominantly with the PC. These issues have included:

1) PC stuck in a reboot - Restart loop and it wouldn't start up after Windows diagnostics
2) USB ports were not recognised and wouldn't pass any information through
3) USB hubs wouldn't load nor run any drivers
4) Camera drivers wouldn't load and camera wasn't recognised
5) Mount plate solving wouldn't work and mount wouldn't connect
6) Wifi wouldn't fire up on Eagle2

I reached the end of my tether and the Eagle went back to Italy to be looked at as I was convinced that there was some hardware fault (perhaps RAM or SSD drive). PrimaLuceLab tested it all and did find that there was some issues with some Windows updates and so reformatted the drive, tested it all and sent it back. 

When it arrived I gleefully fired it all up and it went immediately to a restart - reboot loop, windows diagnostics and wouldn't start up.... Eventually it became clear that the ONLY difference between the PC working in Italy and on my terrace was the power supply. Based on Ray's recommendation I got a 30A linear power supply..... I tentatively fired it all up when it arrived. The mount runs on the cigarette lighter, the PC on the banana clips and the lakesides plug directly into a 'pushy down wire holder'

Imagine my delight when EVERYTHING worked and it has worked now for a few nights.

I would not have believed that mains power could have caused the many issues I was seeing, but  now that the power is clean from the power supply my problems are behind me.

If you have read to the end of this, I guess what I am saying is never discount the unbelievable or silly sounding.... A PC plugged into the mains power would be problematic? Nope, doesn't make sense, but it sure did. Investigate everything, even the mad and leave no stone un-turned.

I hope that this will at some stage help someone to be able to diagnose the ridiculous!!

Edited by swag72
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Phew... those darn astro-Gremlins find their way into all sorts of strange nooks and crannies. There is little more satisfying than crushing them and seeing the kit purring away, working perfectly. Long may it all work sweetly for you Sara and this be the end of these woes.

No doubt there are plenty of other woes awaiting with those pesky Gremlins just around the corner...!!! :BangHead:

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Had a similar thing going on with a DC converter which caused all sorts of USB disconnections... Not easy to diagnose and only figured it out pretty quickly because it was the only thing I recently changed. Makes the case for only ever changing one thing at a time...

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Yay glad it is all working well Sara.  Power supply issues can be so hard to diagnose as they can affect so many seemingly totally unrelated parts, but whose only common factor is supply.

I could feel your frustration, but also have to admire your persistence as I would have launched the lot off the edge of a mountain top with the problems you've had!

Happy imaging and fingers crossed for some better skies (even in Spain).

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37 minutes ago, swag72 said:

Based on Ray's recommendation I got a 30A linear power supply..... I tentatively fired it all up when it arrived. The mount runs on the cigarette lighter, the PC on the banana clips and the lakesides plug directly into a 'pushy down wire holder'

And the key word is LINEAR. None of that nasty switched-mode stuff!

I had a similar (though not so fraught) story with an HEQ5. For the life of me, it looked as if the problem was a low-cost USB-serial board. Intermittent comms failures, corrupt data, spontaneous slewing. But no, it was simply that I was running everything except the PC off an old laptop power supply.

The first step in diagnosis was to toss the power supply and swap in a 12V SLA battery - perfection. After that I bought a nice hefty toroidal transformer¹ and used that as the core of a new power supply, with step-down SMPS boards for the various voltages.
I have the impression that some mains switchers have a strange setup with RFI suppression capacitors on their inputs (I don't recall the details) which makes them prone to noisy 0V lines.

 

[1] That I sourced from RS. Along with all the other bits: electrolytics, bridge rectifier, etc. For some reason RS Spain decided to ship each component individually by courier - one per day. While I didn't have to pay extra for the 4 or 5 deliveries, each day I got a call from the courier company "Hola Peter, Tengo un paquete" But since no courier will take the 30 minutes to drive out to my house, I had to make a 20km round trip to collect each one. Always hopeful that this time it would complete the order. Sorry RS. In the UK you are fantastic, in Spain .... never again.

Edited by pete_l
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In complex (actually in simple as well) systems like astroimaging setups one of the problems can be ground loop. Ground loop in electrical system occurs, when two points that should have the same potential actually have different voltages. Ground loop in astroimaging setup may occur, when ground (i.e. minus of power supply voltage) is connected to one receiver with more than one cable path. It is pretty easy to achieve when you split power lines to distribute power to different system components, or use different power supply but with common ground (it is most often enough to connect devices with USB cable to have common ground). Ground loops can cause communication problems, connection problems and in extreme cases can break some fragile devices. They are extremely hard to investigate, because ground loop may or may not cause problems, even in the same setup with the same cables. The reason can be one defective socket with high resistance or any other small detail. It is best to avoid them when planning setup, but it is not always possible. 

Switching power supplies are quite ok as long as they are galvanically isolated from AC side - this is not always the case even for medium priced power supplies. If the device cannot be powered with good quality switching supply then it is actually not power supply, but this device problem. You cannot assume that power line will always be EMI free, because EMI can be inducted for battery powered line as well. 

Edited by drjolo
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1 hour ago, AngryDonkey said:

Had a similar thing going on with a DC converter which caused all sorts of USB disconnections... Not easy to diagnose and only figured it out pretty quickly because it was the only thing I recently changed. Makes the case for only ever changing one thing at a time...

In this case I hadn't changed anything...... the mains 'brick' clearly just disintegrated over time as it used to work without a hitch.

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1 hour ago, drjolo said:

In complex (actually in simple as well) systems like astroimaging setups one of the problems can be ground loop. Ground loop in electrical system occurs, when two points that should have the same potential actually have different voltages. Ground loop in astroimaging setup may occur, when ground (i.e. minus of power supply voltage) is connected to one receiver with more than one cable path. It is pretty easy to achieve when you split power lines to distribute power to different system components, or use different power supply but with common ground (it is most often enough to connect devices with USB cable to have common ground). Ground loops can cause communication problems, connection problems and in extreme cases can break some fragile devices. They are extremely hard to investigate, because ground loop may or may not cause problems, even in the same setup with the same cables. The reason can be one defective socket with high resistance or any other small detail. It is best to avoid them when planning setup, but it is not always possible. 

Switching power supplies are quite ok as long as they are galvanically isolated from AC side - this is not always the case even for medium priced power supplies. If the device cannot be powered with good quality switching supply then it is actually not power supply, but this device problem. You cannot assume that power line will always be EMI free, because EMI can be inducted for battery powered line as well. 

:laugh2:  :laugh2: :laugh2:  I have literally no idea what you have just said 

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I wrote it in a hurry - bad idea :) I am happy you made it out with your setup and new supplier, I just wanted to point out that there are many problem makers in complex system. As I was told some day "perfect system is system where you removed as many components as you could, and it still works properly" :) 

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11 minutes ago, swag72 said:

:laugh2:  :laugh2: :laugh2:  I have literally no idea what you have just said 

He said, glad it works well with the new linear supply, and that the old SM one which was causing the problems is now in the bin :icon_biggrin:

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@RayD is indeed a Godsend. I have been powering everything from the mains for so long but (touchwood) have never come across any issues. I was so adamant that i was going to plug in my Pegasus power hub through the mains and this is where Ray talked some sense in to my brains and helped me out deciding not only the "Linear" PS but also like yourself Sara made me a cable. Again i wouldn't have known anything about fusing the cable either.

I'm so glad things are working out for you. It's a shame Ray doesn't drink otherwise i would've drowned him in beer by now :)

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6 minutes ago, souls33k3r said:

@RayD is indeed a Godsend. I have been powering everything from the mains for so long but (touchwood) have never come across any issues. I was so adamant that i was going to plug in my Pegasus power hub through the mains and this is where Ray talked some sense in to my brains and helped me out deciding not only the "Linear" PS but also like yourself Sara made me a cable. Again i wouldn't have known anything about fusing the cable either.

I'm so glad things are working out for you. It's a shame Ray doesn't drink otherwise i would've drowned him in beer by now :)

:laughing4:

I would point out that I am absolutely not against SM power supplies.  They are great in the right application and in general work well with no issues.  In fact I loaned @souls33k3r one as an interim until his new one arrived.  However, in both these applications linear was without doubt the best and correct route to take and is why I recommended them.  

I also have no affiliation with the power supply manufacturer or supplier :icon_biggrin:

Just wanted to note that :thumbright:

Edited by RayD

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4 minutes ago, RayD said:

:laughing4:

I would point out that I am absolutely not against SM power supplies.  They are great in the right application and in general work well with no issues.  In fact I loaned @souls33k3r one as an interim until his new one arrived.  However, in both these applications linear was without doubt the best and correct route to take and is why I recommended them.  

I would second that. Ray never said SM was a bad power supply for the kit that i wanted to power it just made sense to use Linear. Truth be told if he hadn't mentioned what these both did and in fact mentioned the name "linear", i wouldn't have even known there were two types of PS in existence.

4 minutes ago, RayD said:

I also have no affiliation with the power supply manufacturer or supplier :icon_biggrin:

Just wanted to note that :thumbright:

Why does my PS say "RayD Linear Power Supply" then? ;) ... only kidding :)

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2 minutes ago, souls33k3r said:

Why does my PS say "RayD Linear Power Supply" then? ;) ... only kidding :)

LOL!  I told them to replace that with QJE!!! :angel9:

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Back to the OP though. 

All power supplies can fail after time, including linear ones, but SM ones tend to do so more often because they are a little more complex in the way that they work and the very high frequencies that they work at (usually up to around 1khz as opposed to the 50hz on a linear).  These high switching frequencies are good in one way as it allows items such as the transformers to be reduced in size, but it is also what causes the 'noise' often experienced when using them, especially cheaper poorly filtered ones, with sensitive equipment such as CCD's.  When they do fail it is more likely for this to start happening when they are under load, and then ultimately just failing.  I'm pretty sure we have all had a small SM supply fail on devices in our home such as routers etc. at some point; I've had plenty, with Netgear seemingly supplying the worst of all.  I think your was just slowly giving up the will to live.

The linear one you now have has plenty of reserve, the split of connectors that you wanted and, whilst admittedly not as efficient as a SM supply, is very well suited to your particular application.

It's all working now, which is a good start at least :icon_biggrin:

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17 minutes ago, RayD said:

All power supplies can fail after time, including linear ones, but SM ones tend to do so more often (...)

I could not say, because I do not have any linear power supply at home since quite a long time. All supplies that fail at my home are now SM :D 

But, to be fair, I think that bad reputation for SM supplies comes from cheap ones that are often included in standard packages of consumer electronics. Switching power supplies that come from reputable companies are pretty well quality - noise free, well protected, efficient, but also not cheap.

 

 

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My guess is that although the eagle itself is a relatively low-power unit, that it was all the stuff hanging off it that was dragging down the PSU.

This would explain the USB ports/hubs being particularly flaky.

One very useful investment I made was a few quid on a USB lead that displays volts and amps - all USB chargers are not created equal and it has allowed me to select and match chargers with devices. The one that came with my Moto phone puts out 1.8 amps and is very quick, for example. Some cheap ones are less than half an amp. bear in mind that many devices manage what currrent they take.

I had a look on ebay and found this:

https://www.ebay.co.uk/itm/USB-DEVICE-CAPACITY-TESTER-CHARGING-MONITOR-METER-VOLTAGE-CURRENT-VOLTS-AMPS-MAH/172363666513?hash=item2821acd451:g:ICoAAOSwLnBX85lw

I suspect that for £9 this would be a godsend for anyone daisy-chaining USB astro devices.

Out of curiosity, what was the rating of the old PSU?

 

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Just a thought... the only SMPSU we have had fail in the last few years was... an Apple Macbook one!

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7 minutes ago, Stub Mandrel said:

My guess is that although the eagle itself is a relatively low-power unit, that it was all the stuff hanging off it that was dragging down the PSU.

That was my first thought, but the other items such as mount etc. were actually running on separate supplies.  I think it was just the supply starting to fail under any load is it seemed at its worst during boot, and what made it quite hard to pin down. 

It was a 10A supply, so plenty enough power for the loads we were testing it with.

The benefit of this method as well now is that the mount can run via the new supply at 13.8v, which the EQ8 is much happier at than 12v.

Edited by RayD
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15 minutes ago, drjolo said:

I could not say, because I do not have any linear power supply at home since quite a long time. All supplies that fail at my home are now SM :D 

But, to be fair, I think that bad reputation for SM supplies comes from cheap ones that are often included in standard packages of consumer electronics. Switching power supplies that come from reputable companies are pretty well quality - noise free, well protected, efficient, but also not cheap.

 

 

Agreed.  Problem is the vast majority of SM supplies on the market are the cheaper ones.  The very good quality ones, with very well filtered outputs, are very expensive.

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16 minutes ago, Stub Mandrel said:

My guess is that although the eagle itself is a relatively low-power unit, that it was all the stuff hanging off it that was dragging down the PSU.

This would explain the USB ports/hubs being particularly flaky.

One very useful investment I made was a few quid on a USB lead that displays volts and amps - all USB chargers are not created equal and it has allowed me to select and match chargers with devices. The one that came with my Moto phone puts out 1.8 amps and is very quick, for example. Some cheap ones are less than half an amp. bear in mind that many devices manage what currrent they take.

I had a look on ebay and found this:

https://www.ebay.co.uk/itm/USB-DEVICE-CAPACITY-TESTER-CHARGING-MONITOR-METER-VOLTAGE-CURRENT-VOLTS-AMPS-MAH/172363666513?hash=item2821acd451:g:ICoAAOSwLnBX85lw

I suspect that for £9 this would be a godsend for anyone daisy-chaining USB astro devices.

Out of curiosity, what was the rating of the old PSU?

 

The problems persisted when there was nothing running on the Eagle at all and nothing was even plugged in... so nothing was actually drawing any power. 

The power brick (I assume that's the PSU?) was rated at 10v... the input on the Eagle was showing at 12.7 - 12.8v. 

Edited by swag72

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9 minutes ago, RayD said:

......The benefit of this method as well now is that the mount can run via the new supply at 13.8v, which the EQ8 is much happier at than 12v.

The mount did have it's own power supply running at 13.8v anyway, so this was never an issue with regards to power, although it failed to connect and plate solve on numerous occasions.

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1 minute ago, swag72 said:

The mount did have it's own power supply running at 13.8v anyway, so this was never an issue with regards to power, although it failed to connect and plate solve on numerous occasions.

Ah ok I didn't know it was already 13.8v.  

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Just now, RayD said:

Ah ok I didn't know it was already 13.8v.  

Yes, so now I have a spare!! :) Don't know how long it will remain as a spare!! :D 

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