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Support (Please note, this is primarily a user forum, for direct Atik support, please email support@atik-cameras.com) => 3- and 4-Series Cameras => Topic started by: ToniMancera on February 28, 2012, 02:01:32 pm

Title: Atik 383L+ Mono, Power supply and the noise problem
Post by: ToniMancera on February 28, 2012, 02:01:32 pm
Hi Steve

Last wekend I am lost 3 hours because the noise comes again, it only appears when the power supply is underneath the 12v.
That is a real problem for me and a lot of 383 users, I usually go out with a 12v full charged car battery, but it can not support over the 12v.
I think about use a power inverter (like that QHY ones) to take 15v from the 12v but I unknow the max voltage is the Atik input.

Can you tell me the max input voltage?

That is a good idea, because the power inverter can run and take out a constant voltage from 10v to 12v input. Has the customer service any plan to solve this 383 problem?
The 383 users need any solution on this.
If Atik can manufacture a power supply from 12v, I like to buy one.

My frien Vlad ask and send to you some fits with the problem, all on this post
http://www.atik-cameras.com/forum/index.php?topic=84.0 (http://www.atik-cameras.com/forum/index.php?topic=84.0)

Regards
Toni Mancera
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: ruitripa on February 28, 2012, 04:46:37 pm
Hi Toni,

Just a small note on batteries. A car battery that is fully charged should output close to 13V. It should never go below 12V, or the battery will suffer some damage, with resulting capacity loss over time and premature failure. If you're saying that your fully charged battery already has ness than 12V, than I'm afraid your battery is dead...

Atik cameras can run up to 13.8V.
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: ToniMancera on February 29, 2012, 12:02:33 am
Dear Rui,

I'm afraid I cannot agree on your points regarding voltage. As a mechanic in a workshop for the passed 10 years, I can assure you batteries don't necessarily "die "bellow 12 V, and voltage will drop bellow 12 during a night of imaging - practically all the time.  And you can confirm this with your local mechanic if you like.  A fully charged standard 68 Ah battery will have anything between 12.7 and 12.5V and around 11.5 when half charged, and at this voltage , it should still be able to keep the camera running well. Tests we have made show that the Atik 383L+ already starts presenting signs of deterioration in the image when falling bellow 12.3V! This for all practical purposes gives me  about 2.5 to 3 hours of imaging  on a fully charged battery. And I have to stress, this does not happen with similar cameras I have witnessed in the field.
It's all very well if the camera needs higher power requirements, but I think when one  buys it one should be made aware that you either need a dedicated deep cycle battery (probably costing about half what the 383 does) to run the camera, or keep it in an observatory to run on stabilized 13V power supply, because as the the situation stands right now, I'm dragging 2x80 Ah lead acid batteries out in the field and the camera uses one of these alone, and after 3 hours I have to pack and go.

As I said in the beginning, if there is some sort of solution, some kind of power stabilizer you can sell, I would like to know about it - although in all fairness this should have been included with the camera. The 383 is a lovely product and a joy to use when it works, don't get me wrong. I just think no one at Atik has actually done extensive testing out in the field before putting it on the market.
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: Lenny on February 29, 2012, 03:44:29 am
You can charge up an old battery and it will show 13 volts or so but after a short time of using it the charge will drop drastically. They just don't hold their charge. You don't say it's a new or old battery so I'll assume the latter. Are you driving the scope off the same battery?
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: ToniMancera on February 29, 2012, 05:46:11 pm
Dear Lenny, around the last year, I'm have do all the photographic sessions with my old Atik 16HR mono, the same mount, dew heaters, Pc, and accesories, all plugged to an only 75Ah car battery, I never see this problem, the 16HR works fantastic all the night.
I've change the old Atik CCD to this new model three months ago because I like Atik's CCD and the problems comes withing.
I lost a lot of nights and sessions for this problem, I just buy a new battery and  now I need to use one for the CCD and another for the rest of the equipmen but  now I think that it's not  enought, can I need a big generator or a nuclear central? Realy it is not a solution.
The problem is to keep the battery up to 12,5v because down 12,5 the noise appears.
I'm looking only for an easy solution, that is a switching porwer inverter from 10/12v to 14v, it can keep a stabilized 14v output.
I need to plug the CCD on my car cigar lighter last night, my car gives about 14v when the engine is on.
Can the 383 works at this voltage? That could be my solution

P.D., I just use two news car batteries
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: Lenny on March 01, 2012, 12:06:23 pm
Don't know the power requirements of the 16HR but it's entirely possible that the 383 takes considerably more. If by "switching inverter" you're referring to an AC power supply that puts out 14V then yes that will do just fine. Atik has already said the camera will work off 13.8VDC. Back in the "old" days switching power suppies could cause noise but the electronics of today are better at filtering that out.
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: ruitripa on March 02, 2012, 01:40:11 pm
Hi Tony,

As a user of "starter" batteries in the field for many years now, I have to respectfully disagree with you. And I mention "starter" specifically, because that's what car batteries really are.

Starter batteries are designed to provide massive currents for very short periods, as you know. They are not designed to provide low currents over a long period, like for example, deep-cycle batteries. There's a lot of websites explaining the differences between them (http://www.batteryuniversity.com (http://www.batteryuniversity.com), for example), so I won't go into detail on the differences, but one thing that is very important is the discharge level. A starter battery that outputs 10.5V is completely discharged and in fact is at risk of becoming irreversibly damaged. Starter batteries should never be discharged below 80% capacity, which means that it should have an open circuit voltage of about 12.3V. Below this battery longevity will suffer, and with it capacity loss will occur. And don't forget temperature, which has a negative effect on capacity as well.

I do have a 65Ah car battery that I use in the field to power my main camera, guider and dew heater. It also powers my laptop in an emergency (when its battery discharges). I can very easily get at least 4-5 hours of use in the winter time (T=5-10ºC), but I have to take some precautions, like:

- Monitor voltage every 30 mins or so with a Voltmeter. NEVER let it go below 12V!
- Don't put the battery on the ground as it gets colder much faster. I put it on the trunk of the car.
- Charge it immediately after use with a proper charger.

This battery is close to 3 years old now, and did maybe 30-40 cycles until now. It's still going ok.

We do have a 12V minimum requirement on all cameras we sell, and the 383 is particularly sensitive to this. But as I said, unless your battery is severely damaged, it should be able to power the camera for several hours without dropping below 12V.
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: RodrigoCastillo on March 20, 2012, 05:47:18 pm
Hello all,

I have also this camera since january and I must say I was observing the same behaviour as ToniMancera says: if the voltage drops under 12.5 (not only under 12v) the noise appears.

I was reading in another forums that some users use a 13.5v power supply. My problem is that i have also a car battery, so my final solution was to build a kind of power supply to get the voltage that I select (in my case I select 13.2v) from an input of around 15v. I can get these 15v from a laptop car adapter (these adaptors have an input of 12v -a car battery- and a variable output from 12v to 20v, in my case 15v is ok). Since I use this solution, the noise is almost null and I could begin to enjoy the camera! If anybody is interested in this solution, please let me know and I will explain it more detailed.

Greets

Rodrigo
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: Lex on March 21, 2012, 01:20:05 am
Hi all,

In my observatory I use a 13,8 V powersupply with a Max of 8 Amps for all my equipment..
The PS never left my astrostuff out of Pwr...
I also read several times that 12V is not enough for everything...

Best

Lex
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: andysea on July 24, 2012, 04:08:32 am
I Have the same noise issue and I'm waiting for a resolution to the problem from Atik, in the meantime I'm saving up for a competitor's equivalent..... I bought the 383L+ just over one month ago. I wish I knew about this issue before that.
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: CCD_Stefan on September 25, 2012, 06:25:46 pm
Hello,
My new 383 has after a view time more and more hotpixel, power off and on, then it is ok.
I think, 12,5 volt is not enough? (Power supply has 10 ampere)
Now I turn the power on 13 volt, I will look at the next night.

(sorry my english, I´m from germany...)
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: stormlv on September 26, 2012, 12:13:22 am
I honestly think that there's no problem with with the voltage...

As I was explaining in a different post related to the new Atik 460Ex- you can have a read here : http://www.atik-cameras.com/forum/index.php?topic=373.0 (http://www.atik-cameras.com/forum/index.php?topic=373.0) - I think the problem lies in the power supply's ability to produce stable ripple and noise free current.

When I was powering the camera from a battery, I even got down to 10.5v and still I had no noise issues - issues that were present when I was using one of my old power supplies.

I have since changed the PS and for now it appears that I'm trouble free...

However, I would really like to hear from anyone from Atik, what their take is on this.
It seems to me, that several people have had this problem already and it's not something that should be considered trivial.

If I were them, I would explicitly add this to the manual
- describe the problem above and refer users to a list of approve power supply vendors
- range of voltage the camera can support
- accurate power supply specs needed, like max ripple and noise specifications, so that we can correctly choose a power supply, for ourselves

Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: taylorgtr1 on October 02, 2012, 01:26:17 am
I too have encountered this. I've had my 383 camera 2 weeks now and have had hours of throw away subs due to not understanding that this was going on. I never knew it was an issue with the 383 being so picky about voltage range. I'm currently looking at power supply options to keep the noise and sensitivity drop off at bay. This camera really needs to be monitored closely.... something I've never been too worried about with my other cameras. I stand by my purchase and will keep an eye on voltage during image sessions. No problem. When this camera is in the optimal zone it takes great images IMO.
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: taylorgtr1 on October 02, 2012, 01:56:54 am
Example with noise...
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: taylorgtr1 on October 02, 2012, 01:58:34 am
Example voltage optimal....
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: CCD_Stefan on October 02, 2012, 06:10:26 am
Hello,
Now I have 13 Volts, it is all OK.
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: andysea on October 03, 2012, 07:19:21 am
Hi Taylor. I have a 383L+OSC and it's very picky when it comes to power supply.
I bought step up converter on ebay. It takes +/- 12v in and steps up the voltage to a set point. The output can be regulated from 12v all the way to 35v. So far the output seems to be very stable - I have it at 13v.
I was getting hot pixels galore before using it but now the camera seems to be working better.
Just search DC DC Boost Converter on ebay and you should find a lot of different options.
I also started a thread on CN a long time ago regarding this very issue.

Andy
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: taylorgtr1 on October 15, 2012, 05:44:07 am
I'm running 13.5 v and have not had a problem since. FYI
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: gvanhau on October 22, 2012, 08:16:36 pm
Hello
I have losts of pictures wasted due to this (at least three new moon sesions), at first  I didn't realice that this was a cam problem and only tought this CCD was a lot more noisy than my QHY8L cam.

Lastly I am not takink this cam to the field anymore, and I am using it only at home where I can provide it with a regulated Power supply at 13.2V.

However, I think, Atik should at least tell us which are the upper voltage limits of this cam in order to build a solution we can take to the field.

Geert
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: andysea on November 02, 2012, 08:56:15 pm
Hi Geert. A while ago I started a thread on Cloudynighst about this issue. I think all we can do is make sure that this becomes a known issue or get a different camera. I wasted entire nights of imaging too.

Andy
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: Chris on November 06, 2012, 12:01:28 pm
The best way to demonstrate a camera noise problem is, I believe, to take two bias frames.

Subtract one from the other; what's left is the noise and because there is no light and no dark current there's not much other than camera read noise.  Do this with the same conditions (CCD temerature) as you would use for imaging of course.  No need to spend precious dark sky time doing this.

Try this with the good and bad power supply and send the data to Atik.

Light frames are difficult to evaluate because there are so many other sources of noise, for example a very thin layer of cloud could increase the sky brightness and look like additional noise.

Chris

Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: gvanhau on November 06, 2012, 01:23:04 pm
Hello Chris

The problen as far a I see is not readout noise (bias).
Instead, it is like a lot of hot or semi hot pixels arise when power supply is below 12.5V.
I even tried to do darks at the same conditions and they are not representative of the nosie, There must be some light falling on the CCD in order to gate the noisy pixels.

The only way to demostrate the noise condition is to take pictures of the same object at different power supply voltages.

regards
Geert
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: afm038 on November 11, 2012, 04:07:49 pm
I've been following this thread with interest, my 383 mono to me seems extremely noisy (set at -20 degC cooling) - the raw fits image straight out of the camera into maximdl look like it's been pebble dashed !

Could someone please post or link to a raw fits image direct out the camera that I can have a look and see if mine is particularly bad ?

I run the camera from a bench "12volt" 10Amp bench supply which gives 13.6 volts. I also tried a standalone mains 12volt 5 amp supply which again gave 13.6 volts, there is little or no difference between either images when in use.

Thanks, Andy
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: chrisjbaileyuk on November 12, 2012, 10:29:03 am
Andy

This is a recent one of mine at -20C. http://dl.dropbox.com/u/80198246/Tycho%20401725_11%2011%202012_1200.000secs_-20.03C_Light_00000092_Ha.fit. This is after changing power supplies to a much better one, 10 amp which measures 13.2 volts under no load (which made huge improvements). I have gone colder but it does not seem to make much difference and I think other noise gets worse as the cooler works harder.

The "speckles" are annoying but fairly easily removed. I use PixInsights Cosmetic Correction on Auto Detect and it kills 99% of them. Sigma Clip stacking does the remainder.

Hope that helps

Chris
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: Lex on January 08, 2013, 06:25:52 pm
Hi Guys,

I had a similar problem not long ago; a bunch of hot pixels on my captures. The operating voltage should be between 11 and 14 V or so; my setup runs @ 13.8V with no problems.

Before I had a 12V adapter and the origin of the problem was a non conform insulated fan of the primary Newtonian mirror. After swapping out the cooling fan the problem was not really solved. I do use a Fan Heater in my warm room during cold winter nights; this one also had to be replaced. This done; the hot pixels were gone without applying DBE or Cosmetic Correction; last ones can concentrate on more Picture relevant details...

Best
Title: Re: Atik 383L+ Mono, Power supply and the noise problem
Post by: Gib007 on May 01, 2014, 05:01:45 pm
I just wanted to add to this useful thread that I've just come across the same problem with my ATIK 383L+. It has happened a few times in the past but not as often as now. I use an 85 Ah Marine Deep Cycle battery. I am intending on giving it a 24 hour charge now to see how it fairs but I tend to charge it overnight after every night of imaging. All I power off it is my Avalon M-Uno mount and the ATIK 383L+ at -10°C (about 28°C below ambient so not full capacity!).

On my Avalon M-Uno mount, I have one of those "universal laptop car chargers" to convert the 12V input from the battery to an output of near 15V (realistically it's around 14V). This prevents tracking problems. I thought the ATIK 383L+ didn't need this but I guess I was wrong. I've ordered another (they cost like £10 on eBay, including delivery) and will use this at the 15V setting (should provide about 13.8V) to power the ATIK 383L+. Hopefully that does away with any issues. Sad that I had to throw away last night's M51 Hydrogen-Alpha exposures. They looked like they'd really enhance my current M51 data! :(

EDIT: I have invested in one of these: http://www.ebay.co.uk/itm/350975904870
It's a DC-DC converter with continuously adjustable output voltage. I'll use it to ensure the voltage reaching the camera is a regulated 13.5V. This will prevent this problem from ever appearing again.