Precautions for pc in the obs?

[Gasman]

Hi guys

Not sure this post should go in this section?.

I`ve just configured a small tower Linux pc solely to use in my observatory and wondering what extra precautions I should take with it?. I was thinking of installing it inside a small mdf cupboard with a low wattage bulb underneath to keep the damp/cold at bay. I have used a laptop previously which I just put in the obs as I needed it but this will be long term. The observatory is a Pulsar fibreglass one so not insulated at all. Wondering if others with permanent computers in their obs`s have done anything else please?

cheers and happy new year

Steve

[hughgilhespie]

Hi Steve,

I also have a Pulsar obsy. I have an old Dell laptop from fleabay as the obsy computer. I have installed a dehumidifier - http://www.dry-it-out.com/DD822-Graphite-dehumidifier - and it seems to keep the laptop happy. The dehumidifier is set to 50% RH and is on permanently with the extracted water piped to outside the observatory.

No problems so far after 1 months use. The laptop is on a wooden shelf which is also supposed to help prevent condensation. The survival of the laptop is crucial for my plan to automate the obsy. So far, I have run Cat 6 cables to the obsy and enabled Wake On Lan on the laptop so that I can turn it on and off from my desktop. Next step will be to get it to control some other bits and pieces.

Regards, Hugh

[skybadger]

I have always run a freestanding pc in the observatory (10 years now ?) with no special precautions other than to block off the big holes to prevent ladybirds. The background heat from the PSU is enough to keep it alive, even when powered down. No need for a bulb.

Having said that , I recently changed to a fibreglass dome and the condensation is chronic so I guess the biggest risk is dripping water off the insides of the roof. There must be a better way than running a dehumidifier....

Mike

[Macavity]

No personal experienceof these, but you might consider a solid state drive, rather than a hard disk with moving parts? Similarly, replace *any* cheap (sleeve bearing) fans on electronics with better quality ball bearing versions? There are performing CPUs which manage with a passive heatsink, these days? 

Personally, I decided to go completely "remote control" by installing a powered USB hub in the observatory, driven by a RELIABLE 30m USB link (over CAT6) from the PC located permanently indoors. But it seems this is not the way astronomers (usually) do things.

http://www.amplicon.com/Data-Comms/product/USB-USB-125.cfm

If I want to debug things, I can take a laptop or notebook into the

observatory and connect "backwards" via TeamViewer.

[Robd]

I cover mine with a fleece blanket during the winter months. Consider a polythene sheet as well if there is a risk of condensation dripping onto it.

Folded fleece then acts as a cushion or wrap as required.

Rob

[Physopto]

Dehumidifiers can be very expensive to run over time, as can a light bulb. An open bottomed box made out of fibreboard insulated on the inside with foam and sealed on the outside with a varnish coat. Put a foam draught strip on the bottom edge all around. Then you can use a damp control tub inside the box, you know the type you fill every so often with white crystals. When placed over the tub and computer, the crystals will absorb any moisture and keep the computer environment dry. Or you can buy silica gel desiccant that can be reused after it turns pink by putting in an oven overnight at about 60DegC. The silica will eventually change back to white (ish) and then can be reused. Having the box almost airtight is the answer.

Best of luck

Derek

[Fish]

Mine sits raised off the floor on a shelf at the bottom of obsy and has been ok it is stored with no power on and left uncovered.

[Gasman]

Thanks for the info peeps . i`m not really into controlling the scope/mount remotely from inside the house, far too many cables to catch and I don`t know if Ekos has the mount swing limits that eqmod has ( I think it has somewhere??). I used to have a low emission low wattage bulb underneath my wood turning lathe in my workshop during winter to protect those precious head stock bearings and it seemed to cope ok. I wasn`t aware that heat was still produced from the pc power supply even with it powered down so that would probably be adequate. We do try to keep electronics cool when using them fans, cooler units etc so maybe the pc would cope better cold. Maybe the mdf cabinet is a bit OTT .

cheers

Steve

[ottUp]

I have a PC permanently located in my uninsulated observatory.  And here in Canada the temp ranges from +30 C in the summer to -40 C in the winter.  Most of the winter it spends most of the time at -10 to -20.

I used to have problems with a former PC in that it would sometimes fail to start when very cold. The lubricant and joints in the disk drive tightened in the cold and this was reported to the PC as "drive failure".  After sitting in that state for 1/2 hour or so (so the power supply was on and the BIOs running) a restart would usually work.  For a while I ran that PC with a small heater installed inside the cabinet and that worked very well (here is a link to that project if you're interested) but eventually I needed to replace the PC and I didn't re-do the heater project.

The real solution, however, was to eliminate moving parts.  My current PC has a solid state drive and is 100% reliable, any temperature.  It's an easy upgrade, and I highly recommend it.

I also keep a "no-freeze" heater in the observatory - it's a small thermostat-controlled unit that simply holds the ambient temperature just above 0 C.  It doesn't seem to take much power, and has completely eliminated the frosting and condensation that I used to experience on cold days.

My general workflow now is to open up the roof, start things up, then operate remotely from indoors via VNC to the observatory computer. (I buried power and GB Ethernet cables to the observatory some time ago.)

Another very handy setup:  I have the observatory PC configured to respond to "wake on lan" commands, and I have the CCD camera powered by one of those power outlets that comes on whenever the PC boots.  This means that I can start the PC and camera to take dark and bias frames without even having to go outside.

Regards

   Richard

[Physopto]

Hi all,

 The reason I mentioned the Cabinet was because it is a case of belt and braces really. Everyone here in the UK lives in different climatic conditions. Some areas are  prone to bad condensation whilst others never see much at all. Canada I suspect  (having a friend over there) is too cold to see the wet damp conditions for most of the time. I also have friends over on the continent and they hate the British climate. Even though their temperatures are much colder in the winter, they recon our dampness  makes them feel the cold much more.  Solid state hard drives are still very expensive I think. Horses for courses I suppose. To my way of thinking any cheap alternative to spending a small fortune on electricity is money in my pocket for another bit of kit.

Regards

Derek

[Gasman]

Thanks again guys for the very useful info!.

I like the idea of a heater in the pc Richard, which reminded me. I am a field engineer and have a laptop permanently in my van and on very cold days I notice when it boots up it has a built in heater linked via thermostat specifically to warm up the hard drive so they obviously are available, have to have a word with our IT guys to see where they source them! I assume a desk top  monitor would be ok kept in the cold? The monitor in my van is fixed in the visor!

best

Steve

[ottUp]

I assume a desk top  monitor would be ok kept in the cold? The monitor in my van is fixed in the visor!

best

Steve

I've never had a monitor harmed by being in the cold. However, LCD monitors don't work well at all in the cold - the contrast fades until the display is almost unreadable.

This isn't generally a problem for me since I tend to be doing most of my control from inside the house via VNC.  However, friends who actually need to use their monitors outdoors have told me that they fasten a heating pad (purchased from a rehab & medical supply store) to the back of the monitor to keep it warm.  (I've done a similar thing - fastening a chemical heat pad to the back of an LCD hand control on a mount to keep the LCD display visible in the cold.)

- Richard

[kev]

Lcd monitors in outside ive found to be a no no, old vdus are ok but need to be kept dry. Some of this is probably due to my location - top of a hill in a seaside town. My pond monitoring pc (yup u read that right) is in a wooden box with its vdu, and runs fine. Except one hasto remove the spiders n web from time to time!

Sent from my iPhone so excuse the typos!

[Gasman]

Well thats a bu@@@r I`ve just got an LCD monitor for the obs, mmmmmm. I`m not far fron you Kev here in York where this time of year temps can average maybe -1 to -5 with extremes of -10. I think the visor screen I have in my van is an lcd one which seems to work ok at sub zero temps, think I might just chance the monitor for now and keep it covered in a blanket.

best

Steve

[kev]

By york it should hopefully be a bit dryer. Usually we are about 5c warmer than york due to the sea. Last night was only -2 here. Hoar frost everywhere mind you.

Sent from my iPhone so excuse the typos!