Astro350D Modifying Process 3

Astro 350D Modifying Process( 3 )   Process-1 ☞    Process-2 ☞

12.assembling airtight chamber to the camera

Use screw 1-6 to fix airtight chamber to camera. First put optic axis levelness coreection washer then use 1-3 screws to fix it.

There are three 1mm diameter holes in green circle in a picture. This is for leveler‘s three legs checking CMOS levelness with optic axis.

13. CMOS sensor levelness

Put glass plate on the camera tripod. Then put leveler so it can be leveled. Put the camera so that the fixed lens of the camera will face down, put leveler over the three holes in the airtight chamber’s rear lid. put the leg of leveler down to the CMOS so that  we can check the levels of the CMOS. Fix the thickness of the washer at point 1-3 as in the picture so that it is leveled.

After the leveling process tape all the screw holes and the hole for checking level so it is firmly sealed and assemble and camera’s rear lid again.
14. assembling EXcooler

If cooling fan breaks down and it stops working, heat sinks can’t release the heat and peltier device will break down because of the overheat. To prevent this we have to put switch that works and 50℃(122˚F) at heat sink, and connect it to the 12V input power line.

I wired connector cable which connected with airtight chamber cover’s DSUB connector at camera’s mainbody to the jack and connector sticked to little PCB plate inside the EXcooler with solder.

I put in the circuit using Variable resistance to vary voltages 5V-12V to controll the speed of the cooling fan.

This is used because when taking a pictures of the stars, temperature changes of ambient air (about 3℃) and so does CMOS cooling temperature, it can hold on to this changes.

15.testing cooling temperature

When air temperature is 33℃(91.4˚F), EXcooler’s fan speed is at MAX CMOS’s temperature will be 12.1℃( 53.8˚F) and airtight chamber’s rear lid lowest temperature will be 28.1℃(82.6 ˚F ).

Calculating relative humidity and dewpoint, there will be no dew at approximately 70% of the relative humidity.

Very rarely when relative humidity goes over 70%(one of those minor days..) we can prevent dew by fixing EXcooler’s fan speed to low speed. This can make airtight chamber’s temperature to go up 3℃, and this will prevent dew until 80% of the relative humidity.

16.Finish assmebling

Solder the stainless sheild plate back whrer it was in mainboard. Connect two FPCB cable from camera’s rear lid to mainboard and close the lid and put all the screws back on and finish assembling.

I’ve fixed Excooler to airtight chamber base housing firmly with two M5 screws. I did it so that I can easily fix it with cooins.

If you look at the bottom of the EXcooler, there is 12V power jack, mini USB jack, Remote controller jack, and a thermometer jack.

there are also a serial number here.

Left bottom is the picture of camera with closed cover to protect Copper Block at side of the camera. Pictures will be taken at this condition at normal pictures at days, and picture comes out neat and compact. Right is picture of camera with EXcooler, which is for taking pictures at night.

Process-1 ☞    Process-2 ☞