ASI1600 et al Camera - Sensor Window Heater On the Way

[glend]

I ran across a post by ZWO (Sam) on the Cloudy Nights forum concerning a question about sensor window fogging. Sam has obviously been following the discussion about the need for a window heater. The competition (QHY) has a heater in their camera. Previous advice from Sam on this, was that the camera sensor board would need a redesign to accomodate an internal heater. It seems they have been working on an external heater that is applied to the front cap of the ASi1600 (and other cooled ASI cameras). I have an image of it here:

http://zwoug.org/download/file.php?id=1315&mode=view

When I emailed Sam my concerns about it shorting out on my filter wheel (which my camera is screwed to directly by those short M42 male threads) he assured me they have tested it with their filter wheel, and that that clear shinning stuff is a membrane over the heater elements. If you want gap separation he suggested a 1mm M42 spacer would do the job and still provide a solid connection to the filter wheel. Sam has said in the email that the AR window temperature would go up by 10C as a result of the heater.
No word on availability yet.
I will make an assumption that the heater must be powered just like any other dew heater, via an RCA plug and separately to the Camera TEC power, otherwise the amperage required would go up and you would need some way of controlling the heater. I expect more info on that soon.

[glend]

ZWO have the ASI camera heater now available for ordering on their website, price is $19 USD, and more details are provided:

https://astronomy-imaging-camera.com/products/accessories/anti-dew-heater/

I have ordered mine.

Also, re the power for the heater, the heater kit comes with a Y splitter cable so the camera 12V power (normally just for the TEC) is used to drive the heater as well. The heater power output is 4.2W . The heater can obviously be powered separately if you want to . As long as your camera TEC power supply is rated at over 2amps (which is what the TEC needs) then it should be able to supply the heater element as well.

[spiezzy]

Thanks Glen
have ordered mine as well great price to boot
cheers Pete :thumbsup::thumbsup::thanx:

[glend]

The ASI1600 heater arrived today, very quick service. I have installed it, and used the opportunity to put in some new dessicant pills and replace the AR window (which i scratched when cleaning it with a sensor swab that was not clean, another story). I filled the sensor chamber with argon and taped up the seam with PVC tape. There is an internal O ring that the cap presses into, and the AR window has an O ring as well, so it seems pretty well sealed.
The heater is pretty easy to install, centering it is important of course, and there are two thin plastic stand off spacer rings supplied which go around the AR window, this is a good idea so that you can't screw the filter wheel on so far that it scrapes the membrane on the heater. The Y cable allow you to run the heater and TEC power off a single 12V plug, but of course the combination will draw a little more power, and it would be always on. I am thinking that I will separate these two power leads so that I can turn it on only when needed. I was not happy with the big stiff cable ties supplied so I will be using some from my supply. Photos attached.

Update: I just conducted a quick test using a battery and dedicated lead to the heater. Starting temp was 23C and after 20 minutes the cap edge was 30.6C, measured using an infrared temperture gun. ZWO claim an increase of 10, not sure if that was F or C. The issue i have is that it was heating the filter wheel as well as the camera cap, which maybe a good thing. So obviously the filter wheel is either touching the heater membrane or heating through the screw threads. A thin sheet of neoprene might insulate it better, or even some pvc duct tape over the back of the wheel housing, nothing too thick obviously. A cold night field test will be needed.

[Windston]

Its great to see a company like ZWO acknowledge their product had a minor flaw, and to come out and fix it, let alone the cheap as chips price!

:eyepop: Very impressed!

[glend]

My ASI camera heater has failed. I had noticed that the top of the camera was not getting warm anymore, and found a condensation spot on the sensor window. When I removed the filter wheel to inspect I found the +12V wire had broken at the point where it attaches to the heating element coil copper tape. When I installed it I followed the ASI instructions and secure the power lead with the supplied cable ties at the top and back of the camera. I can't tell why it failed, whether through corrosion caused by dew or poor soldering of the wire to the copper tape tab. I have sent the info to Sam at ZWO along with the photos attached here.
If you have one of these heaters it is probably a good idea to keep and eye on the heater to see if it is still performing. I will advise whatever I hear back from Sam.

[traveller]

Good luck Glen, looks like a design fault issue. You'd imagine there is more protection over the critical area between the exposed wiring and where it attaches to the copper heating coil.
Please keep us updated.
Bo

[glend]

I have heard back from ZWO regarding the failed heater unit. They are sending me a new one. I hope the design has been improved. I will let you know when it arrives.

[glend]

The replacement heater element has arrived. The connections for the wires to the ribbon section looks a little different, but it still bends over the side of the camera top. I will experiment with different methods of securing the fly lead this time.

[Nikolas]

if it is a design flaw I don't see why they would be charging people for this.
As a courtesy it should be supplied free of charge.

[glend]

It was replaced under warranty, no charge, they paid shipping as well.

[Marke]

I've had my heater for awhile now but not fitted as I haven't noticed any fogging so far

[glend]

I had been running without the heater since the camera was first released in Early June last year, with no fogging, and its been used for hundreds of hours in all sorts of conditions. I only got the heater as insurance and to test it. If your dessicants are ok and you have no seal leaks it should not be needed imho. They produced one because a few people in the US complained and QHY came out with a heater on their version of the 1600.

[Marke]

Cool good to know I got mine just in case it's cheap any anyway