cctv camera cooling

[shirva]

With the post about mallin cam v's comperitor thought this may be a good topic..

Cooling budget cameras pros and cons and how to achieve better performance with cooling mods and how did you achieve it and costs...davy

[hemmi]

With the post about mallin cam v's comperitor thought this may be a good topic..

Cooling budget cameras pros and cons and how to achieve better performance with cooling mods and how did you achieve it and costs...davy

I have attempted this once on the LN300.  I was able to cool the sensor enough to reduce warm pixels, but it took a massive amount of power.  The cold finger was super thin to fit under the sensor, so required alot of power to keep the peilter cold enough.  This caused the outside heatsink to get hot enough to cause a fire. So I scrapped this effort, just not enough effect to justify the added weight and power.  Plus TEC cooling requires electronic skill to create the TEC controller.  And to be honest I think it would cause condensation over time that would damage the camera.

I have also had very poor results if any from just using fans.  My sdc-435 camera has a fan, but it just makes noise and has zero effect on amp glow or warm pixels. IMO its just not worth the effort for these low cost cameras.  One thought I have had was to remove the sensor completely and create a remote head with just the sensor and TEC, but again way more effort than I want to attempt. It did however keep me busy during some cloudy nights, so I guess that was a win.

With these cheap sensors I think internal noise reduction with the addition of software that can mast the warm pixels and amp glow are the key.

I look foward to seeing if anyone has come up with something that has made a difference.

[shirva]

In my original scb2000 mod i tried peltier cooler and done thin coldfinger result kept camera at ambient temp..tested by fluke meters..cooling fan mod .i have just now ...40 mm internaly fitted behund ccd board ,40 mm fan on top casing and a 18mm each side at front all fans are sucking hot air out of camera housing....tested blowing and sucking air,...temp better internaly but the best test was on 20min capture without cooling usb grabber dropped approx 800 frames cooling on no frames were dropped...,remodding this camera next week full body mod ,bigger heatsink and fans...davy

[hemmi]

Looking foward to your results.  If you can please post cooled and uncooled darks so we can see the difference.  Thanks!

[Dragon Man]

Already done a full thread in another Forum with pics of Hot pixel loss.

I will copy it all and bring it over. It is cooling my SCC-A2333 (SCB-4000).

[Dragon Man]

Cooling the Samsung SCB-4000 (SCC-A2333)

Here is my own version of how I cooled my SCB-4000 (also called SCC-A2333).

I knew it was dangerous to cool a chip with a plastic housing directly by placing a peltier cooler directly onto the chip, or even the back of the PCB that the chip is attached to, so the trick was to get the whole camera cool enough to make the chip colder without damage from Cold shock, excessive cold, or condensation.

I followed other peoples examples of placing the camera inside an Aluminum box and chilling the box. Then having a fan inside the box blowing the chilled air towards the chip.

Here's how I did mine:

1. I made an RF/Heat barrier doubling as a cold finger inside the camera. This way it blocks RF interference and heat from the lower and rear PCB's.

The cold finger attaches to the camera case at top so cold can conduct through the aluminum.

Then I placed a 5 volt micro-fan from an old Netbook onto it.  I used the 12v power inside the camera to run this Micro-fan through a 5 volt 'voltage regulator' mounted near the back (to keep the extra heat away from the front).

This fan blows the cold off the Aluminum coldfinger onto the back of the chip.

[Dragon Man]

Step 2:

Getting the Coldfinger cold is done by making the whole body of the camera cold using the Aluminum box idea.

I started with 2 pieces of Aluminum Channel made for a shower recess, cut to the length of the camera body.

With one upside down to the other they interlock to make a complete wrap-around casing with small voids each side for electrics to tuck into.

You can see in the pics where I mounted the power sockets for the peltier and the Heatsink fan (I kept these as seperate power lines as the peltier cuts off at 3c degrees but I want the fan to keep running).

The Parasite box for my remote control on the other side.

When all assembled it is a perfect fit around the body of the camera.

Note: I slightly bent a curved shape in the straight sides so they matched the curve of the camera sides. More contact means more effective cooling.

[Dragon Man]

Step 3:

Then I attached the Peltier cooler out of a $29 Car Fridge.

I didn't use the enormous fan or heatsink that came with the fridge. I grabbed a smaller heatsink and fan from a dead Computer in my shed.

I attached the Heatsink using 2 small blocks of wood (poor conducter) so no heat travelled back from the heatsink to the cooled side.

I ran 12 volts into the peltier to make sure all was working good. Once I was happy that it was very very cold, I covered all the external Aluminum surfaces in sticky-backed Flocking Felt as an Insulator.

Now with the peltier running and the Camera very cold, I can't feel any cold on the outside felt, letting me know that all the cold is going inside, not off into the outside air.

[Dragon Man]

Step 4:

The switch.

I used the switchgear that came with the Peltier. It has a Hot or Cold selection but I doubt I will ever need the hot unless I want to thaw the ice off the camera at the end of a session

I mounted the whole switch assembly into a project box and mounted it to the Scopes accessory plate along with my heater control box and laser.

Here you can see it all completely wired up and in use. I took this pic whilst testing it.

Well, that's it until I show you the test results.

Was this cooling Project worth all the work?

[Dragon Man]

Well, lets have a look.

Here is a test done inside my house at 20c degrees ambient (68F) with the lens cap left on.

The sens-up is x128

Brightness at 10%, Contrast at 50% in both test frames (about where I have them for most DSO's).

This first frame is a screen grab at about 20 seconds after the camera was turned on:

[Dragon Man]

Then another screen grab after the cooler had been running for 30 minutes:

[Dragon Man]

You may not be able to see much difference but I can when I flick back & forward between the two.

What makes it harder to see much difference is that from the moment the camera is turned on the little Micro-fan inside the camera comes on too, cooling the chip. I hard wired it in without a switch so that it comes on as soon as I start the camera.

I remember what it looked like without the Micro-fan running and it was a lot worse than the first pic above.

So this shows me that the Micro-fan alone makes a big difference. 

And the Peltier just adds that extra little bit of hot pixel and noise reduction.

So, my conclusion is, It is a success 

TWO MODIFICATIONS TO THE PROJECT

I have already made 2 major alterations to my cooling project even before I have had a chance to get outside and try it at night.

1. I have totally removed the camera's original case, and just use the wrap-around Aluminum cover (shown in my tutorial above) as the case.

This will allow ALL the coldness into the camera, not have it trying to work its way through the steel Samsung case.

2. I have added a 40mm PC fan through the side of the case. It collects the chilled air at the peltier and blows it directly across the electronics inside the camera.

If you look at the above images you'll see where the power sockets are mounted in a void area between the Peltier and the camera body.

This area is full of chilled air. This is the air the fan will blow into the inside.

I have tested it on the work bench and the inside of the camera now gets even colder.

So now the peltier is not only chilling the Aluminum body it is also supplying the chilled air being blown inside. Which also helps chill the RF/Heat coldfinger even further for the other micro-fan to blow colder air onto the back of the chip.

Some photos of the new Alterations:

1. The 40mm Fan mounted inside the Aluminum case

(yeah I know, the hole is cut a bit rough)   

[Dragon Man]

2. top view showing how much of a tight squeeze it is to get the 40mm fan in there! 

[Dragon Man]

3. How it all goes together without the original Samsung case. 

The bottom photo shows the semi-closed-in area where the fan sucks air from the peltier cooled area (the void in behind the power sockets)

[Dragon Man]

4. Close-up of what's been added inside 

The coldfinger and the Voltage Regulator have contact with the Aluminum case and have Thermal Compound on them for good temp transfer.

The idea is that the cold from the case will transfer down the coldfinger to the little micro-fan and blow cold air into the back of the chip. 

[hemmi]

Wow Ken great rightup.  I love how you put the fan so close to the sensor.  Do you have anymore details about the TEC controller?  Did you buy a device with a controller and just repurpose it?  I have not had near the luck you seem to have, but also I have not spent near the time trying as you seem to have.  Very nice mod!  you obviously planned and executed this well.

[Dragon Man]

The Results

This First image is a dark frame with Gain turned up to Maximum, and at x512 sensup.

Camera had only been on for 5 minutes in this image.

[Dragon Man]

Then, exactly the same settings but 30 minutes later when the camera has had a chance to warm up as much as it can.

[hemmi]

I do not see any warm pixels, good job. On my Jr. pro when I turn ACG to max. it ooks like a open cluster, lol.

[Dragon Man]

One of the great benefits of Cooling is being able to take the Gain to very high levels to capture objects in a shorter time without fear of Noise being introduced from the high gain level.

Here is a Screen Grab of Centaurus 'A' Galaxy at the crazy short time of only x96 sensup  

The image is very clean, and has nice color. No Hot Pixels at all.

So to sum up this test, I'd say it was a success 

There is still a bit of experimentation to do on the Amp Glow in longer images, but it is minor.

Thanks for reading this lengthy thread about my Cooling Project 

[Dragon Man]

Wow Ken great rightup.  I love how you put the fan so close to the sensor.  Do you have anymore details about the TEC controller?  Did you buy a device with a controller and just repurpose it?  I have not had near the luck you seem to have, but also I have not spent near the time trying as you seem to have.  Very nice mod!  you obviously planned and executed this well.

Yes Hemmi, the TEC is from a cheap 12 volt Car Fridge that holds 6 cans of drink.

The controller is from the car fridge too. 

The Car Fridge cost me about $29

The micro-fan I used inside the camera is a 25mm (1") fan from an old broken notebook. It is only 5 volts so I use a 5 volt Voltage Regulator to step down the 12 volts in the camera. A computer shop gave it to me for Free.

[Dragon Man]

Oh, and here is what the whole set-up looks like when it is running.

I think I need a regulator so I can turn it down.

nah . . . on second thought, I'll leave it running very cold 

[hemmi]

I'm wondering if the Jr. Pro would benefit from just external case cooling with TEC?  I'm not about to break open this camera

[Dragon Man]

Well, external cooling of the case can't hurt anything Hemmi 

[Carl Reade]

Ken am I right in saying the cold finger isnt directly in contact with the peltier?