Sorry no photos yet, they're still in the camera.
Spent most of yesterday with the smell of solder in my nostrils! I built the K-3070 variable speed controller kit, using my electronics skills dating back to 1988, when I last did some soldering in year 8 at school
It worked!!
Very pleased.
Hooked it up to the fan on one end, and the 12v battery on the other, and around it spun. One thing though, when i'm not putting the full speed through, the fan makes an annoying "whining" noise, but it's not there when i'm running at full speed. Matt, does yours do this? Any idea what it could be?
On reflection, the variable speed controller is overkill as I'm not expecting i'll be running the fan while viewing/imaging. The purpose of my fan is to cool the mirror to ambient
before I start observing/imaging, so a simple on/off switch would've sufficed. I might still replace it with a simple on/off switch control, to get rid of the annoying whining noise and also to simply have a smaller, more compact unit sitting on the back of the scope.
To remove unsightly and annoying wire joins, and to also allow easier transportation, unpacking etc, I soldered some "stereo type" plugs to the wires and some alligator clips to the battery terminal end.
So now, I can unplug the controller from the fan, and I can unplug the battery from the controller. I also soldered a cigarette lighter plug to a separate wire (again with a plug at the other end), so I can switch power to the unit between the 12v battery cell (with alligator clip attachments) and the 12v jumpstarter battery pack (with cigarette lighter attachment) for greater convenience out in the field, depending on what else i'm running at the time.
What's next?
1. Put it on the scope! It's still in the house, not tested in the field yet. I know the mounting plate fits, the fan is already attached to that, but I haven't taken the controller box and battery out at the same time to get it running on the scope. Will do that tonight.
2. Wire the temperature sensor to the mirror. I still haven't taken my mirror out to clean it and attach the mirror temp sensor. So i'm still just measuring ambient. I intend to do this tonight as well, hopefully.
3. Active cooling. But this will come later. I'll just use the fan (in combination with temperature sensing) for a few weeks and see if I can notice any difference, before I go down the more complex path of active cooling. But I can imagine it will be necessary.
The temperature is dropping really quickly right now.. 23+° during some days, and as soon as the sun goes over the hill at around 5pm, the temperature drops very quickly and by 5:30pm, the ambient reading is showing 13°.
I hope this makes a difference to getting the mirror down to that temperature quicker, especially with Jupiter rising so early these days, I don't have as long to wait before starting imaging.
I'll upload pictures tomorrow hopefully, as I'll try to take the last pics tonight with it attached to the scope.
