well success. Whilst waiting for the remainder of my family to arrive for my eldest 6th birthday party, I gallantly told the wife and sister and law I would go down to the garage to supervise the kids riding their bikes.
Once down there, out came the tools and i made the final modification to my cooling system. I will take some photos tonight.
Basically it is a peltier cooler out of a $20 - $30 12 volt car fridge you can buy from retail shops. This has been attached to a 2mm round aluminium plate with 3 little fans then blowing the cold air onto and around the mirror cell. It is 90% sealed as i have also attached a .6mm aluminium sheet so i can screw to the mirror cell where the locking screws normally go.
Bird was very kind in donating his old cooling system, so i have stripped this old 2m plate from that.
Further improvements are needed, but at the end of the day, the cooling rate has increased from less than 2 degrees an hour to around 5 degrees an hour. The 2mm plate is too wide to fit inside behind the mirror and an insulating separator would also increase this rate.
There are 4 fans all up, one large one cooling the heat sink and three small ones. There is one 4amp peltier. I had the system running on a 7amp hour battery and it went well for 1.5 hours. I then plugged directly onto the battery, a 6amp smartec battery charger and the system got an extra boost and kept going.
Total costs, well $30 for fridge cooler, a local engineering shop here reckons 20 - 30 to drill and cut a templated 2mm plate. So well under $100.
But for a start, i am very happy. I was able to get down to 10 degrees with an ambient of 8.8 by 10pm after starting proceedings at 8pm from an initial temp in the garage of 22 degrees. It makes looking at saturn a lot easier!!!
From a 2 degree - 5 degree drop per hour is a big improvement! For that price, what more could a newt owner want as far as primary cooling is concerned.
Congratulations on putting peltiers onto your fridge....um dob. Sounds really good. Is condensation a problem? I have one of those silly cooler/warmer boxes and the little plate is always dripping.
Next thing you need to do is place beer bottle holders on the inside of your OTA. Strap them to the side so they are not in the light path. During your observing sessions, you can simply reach inside and grab a coldy.
There are people out there that make little refrigeration units that they put into the drive bay of their computers. They have tubes that run around the inside of the computer case and distribute the cold. Because they are made to go inside the computer they do not create any moisture. Maybe one of these things would work ok, simply run the tubes inside your OTA.
Hi Dave,
Thats all looking really good, I'm impressed with the 2 deg to 5 deg bit, about what I would have expected, but until you play you don't really know. I notice you have good insulation between the plates which would help tremendously. This has really been a great learning experience for ALL of us!
Regards IanG
I am already thinking of the complete system like birds ie aluminium tube and all. I want a tube that can assemble and break down easily and then attach the base with cooling easily too.
Hey asi, they call the shop version of what you are making the "cat" cooler. Somehow I think yours will be an "african lion" cooler. The front plate will be lifting at the seams due to air pressure. "Yup lets cool the bugga in 45 seconds flat. No mucking around!!"
Lights will dim around port lincoln as you turn him on and the poor scope will cringe from the super duper enema you are about to give to cool it down!!!
, yup, what does 100% maximum warning mean???? = i am sure 150% will work better, 
