Testing Altair Hypercam Simple Cooling Fan

[bobro]

Having recently purchased an Altair Hypercam 183M with a simple fan cooler rather than a TEC cooler, I wondered what effect the fan would have on sensor temperature as it's really an anti-warming fan rather than an active cooler.

So a simple test was to let the camera operate without the fan running to see what stable temperature it reached, followed by turning on the fan at full speed to see how this affected the sensor temperature.

The (indoor) test without the fan running stabilised the sensor at over 28 deg C (actually the temp was still climbing but very slowly). This took about 25 minutes.

With the fan then turned on, the sensor temperature dropped by over 5 deg C in a further 25 minutes - showing the fan does provide a useful cooling effect which will help with the (already low) sensor noise.

With the fan running the sensor temperature looks to be about 2-3 deg C above ambient.

 

[Adam J]

17 minutes ago, bobro said:

Having recently purchased an Altair Hypercam 183M with a simple fan cooler rather than a TEC cooler, I wondered what effect the fan would have on sensor temperature as it's really an anti-warming fan rather than an active cooler.

So a simple test was to let the camera operate without the fan running to see what stable temperature it reached, followed by turning on the fan at full speed to see how this affected the sensor temperature.

The (indoor) test without the fan running stabilised the sensor at over 28 deg C (actually the temp was still climbing but very slowly). This took about 25 minutes.

With the fan then turned on, the sensor temperature dropped by over 5 deg C in a further 25 minutes - showing the fan does provide a useful cooling effect which will help with the (already low) sensor noise.

With the fan running the sensor temperature looks to be about 2-3 deg C above ambient.

 

I hope that test was done inside? Either that or your having much better weather down your end than we are up in lincoln. 

Edit: Never mind you say indoor. 

I suspect that the fan is also useful in providing a stable temperature across multiple sub exposures and that is useful for making Darks without having the benefit of full set point cooling. How long does it take to reach a stable temperature with the fan on?

If it was me then I would probably monitor temperature during an imaging run and then slap the cap on and take a set of 10 darks every time the temperature shifts by more than 2c. Eventually you will end up with a Dark library covering a range of temperatures and wont have to do that anymore. Another way is to leave it out over night taking Darks for several nights with different weather and hence as the temp drops over night you will get dark frames at a range of temperatures and can create a library from them.  

In the end the fan and temperature sensor is certainly a worth while addition to the camera and is why I recommended it over the ZWO version. Its a half way house between a fully cooled camera and a DSLR with it also being mono. Expect significantly better performance as you drop below 10c ambient in the winter months and eventually less....which is of course when it matters most in this hobby, summer nights are short anyhow.

Adam 

Edited May 17, 2019 by Adam J

[bobro]

It's a slightly chilly and damp 12 deg C down here - hence more comfortable testing indoors! (Plus working on the coma corrector spacing.)

When first powered up and already at ambient, with the fan running the sensor settles at 2-3 deg C above ambient within 5-10 minutes, so not much time lost there. 

Good ideas about building a dark library - thanks.

Bob

[Adam J]

47 minutes ago, bobro said:

It's a slightly chilly and damp 12 deg C down here - hence more comfortable testing indoors! (Plus working on the coma corrector spacing.)

When first powered up and already at ambient, with the fan running the sensor settles at 2-3 deg C above ambient within 5-10 minutes, so not much time lost there. 

Good ideas about building a dark library - thanks.

Bob

Yeah the dark current doubling temperature on this sensor is very good, so dark current doubles every 10c or so, most sensors are 5-8c. 

But that does mean have half the noise at 10c as you do at 20c and half as much again at 0c. 

Ada, 

[ebdons]

Hi I have the 174m model with the same fan setup I think, but the hypercam bodies are all the same on the fan versions, so other than keeping the casing and internals cooler when solar imaging, I don't know how effective they are,  and whether the newer hypercams will have a TEC cooler in the future. but they work well and as mentioned would be best for the colder nights.