Cooling fan power supply

[davedavedave]

Evening all,

I'm looking to attach a cooling fan to the base of my Skywatcher 200p dob. There seems to be a good range of pc cooling fans on amazon which would do such a job.

However, what I can't seem to work out is how to power such a fan. Basically the fan would be the only thing on the scope that requires power so I'm hoping I don't need anything to big, ideally something small which I can stick next to the fan.

The fans I have looked at mostly seem to be 12v dc/ 0.25A.

I'd really appreciate advice/pictures/links to such a power supply and also how to actually attach it to the fan (the fans mostly have a 3 pin plug). 

Sorry if this is a really silly, noobish question!

Many thanks in advance,

Dave

[Scooot]

http://www.thesafetycentre.co.uk/store/sealed_lead_acid_batteries_sla_lead_sealed/yuasa_sealed_lead_acid_battery_np7_12_np_7ah_12v_rechargeable?gclid=CNPw5Yjd18ACFRHLtAodUl0AeA

I use one of these to power my fan and or nexus. I think you can get even smaller ones.

[Gasmac]

Maplin do a pc 12v pc fan for around £7-8. I connected it to a low cost li-ion rechargable battery for cctv systems from china and it works well. The thing is to look out for the fan's amp hours and the A/h of the fan. Mine gives about 5 hours which is enough for most nights. Then connect up with a male/female connector of the right sort.

There are many good posts on SGL about how to blank out the bottom end of the tube to get the air flow in the right direction.

Lastly switch it off before collimating in the dark it can be a bit of a surpirse when a whizzing blade meets the tips of your fingers (luckily not very painful otherwise i wiuld have learned my lessson the first time)

[RT65CB-SWL]

http://www.thesafetycentre.co.uk/store/sealed_lead_acid_batteries_sla_lead_sealed/yuasa_sealed_lead_acid_battery_np7_12_np_7ah_12v_rechargeable?gclid=CNPw5Yjd18ACFRHLtAodUl0AeA

I use one of these to power my fan and or nexus. I think you can get even smaller ones.

+1 I was thinking the same.

[davedavedave]

Thanks for your helpful responses. That's just the kind of power supply I had in mind, something relatively small which could attach to the bottom of the scope next to the fan.

I've got my eye on a slightly smaller one from the same place: http://www.thesafetycentre.co.uk/store/sealed_lead_acid_batteries_sla_lead_sealed/powersonic_battery_range_sealed_lead_acid_batteries/powersonic_ps1212_1_2ah_12v_sealed_lead_acid_battery.php

The fan I've been looking at is this one: http://www.amazon.co.uk/ARTIC-AFACO-12000-GBA01-Cooling-F12/dp/B002KTVFTE/ref=sr_1_2?ie=UTF8&qid=1410474501&sr=8-2&keywords=cooling+fan+pc

I can't for the life of me figure out how the two connect together.  And also, how do these batteries recharge, is there a separate cable to buy? I'm sure it's very obvious and simple but it's managing to confuse me!

Thanks again!

[Charic]

davedavedave........There is potential to induce vibration into the telescope from a PC fan un-less its properly damped?  also a longer cooling period to get the temperatures would be more beneficial. I leave  mine for about an hour, but really depends on the temperature variation?  I'm also certain that a standard (or rechargeable) PP3 9V battery can run small PC cooling fans! the type of battery found in smoke alarms. Make sure your smoke alarm battery stays put though! Not sure the 9Volt will last for hours, but you only need it to quicken the cooling.