timthelder
March 26th, 2008, 12:28 AM
Well, I finally finshed the modification/upgrade on my Meade DSI Pro II.
I purchased a kit from TEC Cooling for about $50, which comes with everything you need to do the modification(except for a metal lathe...)
There is a square 'tit' that extends from the inside of the heat sink on the back of the DSI to the back of the monochrome chip for heat dispersion.
The first step in the process is you have to cut off this 'tit' exactly 5.6mm or 7/32 or .220. Since the cut-off point is recessed below the lip of the housing this CANNOT be done with any of the basic tools you have around the house, it also has to be perfectly flat. This is done to allow for the insertion of the peltier, and a small aluminum spacer.
So with a trip to the local machine shop, and an expense of $15, I got my 'tit' cut off.
A couple of holes later, (drilled to accomodate the power input jack for the peltier, which has it's own power supply), and the fan wires, (you also have to tap holes in the back to hold the fan on.)
I soldered the fan wires to the PC board negative and positive terminals of the USB port(the fan is 12volt, but runs off of the 5volt USB line, so it will run at a slower speed thus causing no vibration.)
I put her back together, and here are the results.
On initial start up, the temperature of the cam was 32 degrees C, (in the house.) Since the fan comes on as soon as you plug up the camera, I am not sure what temp it would have stablized at without it running, but anyway, the camera, taking dark frames, with the fan running only, stablized @27 degrees C.
I plugged in the Peltier, and almost immediately the temp started to drop. It dropped all the way down to 16 degrees C, and upon taking some dark frames, finally stablized @18.5 degrees C.
In summary, I figure the modification has dropped the chip temp by about 10 degrees C.
All in all, I'm pleased. :biggrin: The less the noise the better.
I purchased a kit from TEC Cooling for about $50, which comes with everything you need to do the modification(except for a metal lathe...)
There is a square 'tit' that extends from the inside of the heat sink on the back of the DSI to the back of the monochrome chip for heat dispersion.
The first step in the process is you have to cut off this 'tit' exactly 5.6mm or 7/32 or .220. Since the cut-off point is recessed below the lip of the housing this CANNOT be done with any of the basic tools you have around the house, it also has to be perfectly flat. This is done to allow for the insertion of the peltier, and a small aluminum spacer.
So with a trip to the local machine shop, and an expense of $15, I got my 'tit' cut off.
A couple of holes later, (drilled to accomodate the power input jack for the peltier, which has it's own power supply), and the fan wires, (you also have to tap holes in the back to hold the fan on.)
I soldered the fan wires to the PC board negative and positive terminals of the USB port(the fan is 12volt, but runs off of the 5volt USB line, so it will run at a slower speed thus causing no vibration.)
I put her back together, and here are the results.
On initial start up, the temperature of the cam was 32 degrees C, (in the house.) Since the fan comes on as soon as you plug up the camera, I am not sure what temp it would have stablized at without it running, but anyway, the camera, taking dark frames, with the fan running only, stablized @27 degrees C.
I plugged in the Peltier, and almost immediately the temp started to drop. It dropped all the way down to 16 degrees C, and upon taking some dark frames, finally stablized @18.5 degrees C.
In summary, I figure the modification has dropped the chip temp by about 10 degrees C.
All in all, I'm pleased. :biggrin: The less the noise the better.