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Old 10-10-2016, 01:48 AM
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To all the people with the GD access, I have created a new subfolder called Incoming where everyone has write access. If you want to contribute any files to the project, this is the place to upload them. For example, new ideas, different design files, photos, documentation...


Quote:
Like your TEC info...does this include ambient temp changes? Summer time can add 25ºC to the outside HSF.
Brendan, the increased ambient temperature could make the TEC less efficient but it really depends on the temperature of the hot side. With spare cooling capacity on hot summer nights we could just increase the PWM frequency to compensate.
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  #282  
Old 10-10-2016, 04:04 PM
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wasyoungonce (Brendan)
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Quote:
Originally Posted by flolic View Post
A little bit of off topic, I present you few pictures to show how I solved cooling and housing on my KAI4022 camera.
Flip that is beautiful work. Did you press in the copper HSF insert into housing or just sealing it with a gasket?

Brendan
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  #283  
Old 10-10-2016, 04:09 PM
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Quote:
Originally Posted by luka View Post
To all the people with the GD access, I have created a new subfolder called Incoming where everyone has write access. If you want to contribute any files to the project, this is the place to upload them. For example, new ideas, different design files, photos, documentation...

Thanks Luka...I guess we have to now start locking in connectors we are going to use, screws, ...etc. I planned for the JST-EH 4 way for power and 3 way for USB (2.5mm pitch, note note 2.25mm, 3A, in schematics). We can pick these up cheaply and pre-wired from fleabay. They usually sell in lots but we can buy and on send them. c I tried to put this on the BOM but only mucked it up.....you'll see! Tried to put it on a separate page but as said I did a dogs breakfast of it. We probably need this info up for all.

The other connector is the housing. Your idea of the Altronics P9850 appears to fit the bill with sealing and mount hole dia. We should be able to use this and get a good seal.

We still haven't finalised a purge for the housing. This and finalise cooling...edit: oh and a machine socket for the sensor. We looked at some on fleabay but should now be thinking about buying them.

Last edited by wasyoungonce; 10-10-2016 at 04:49 PM.
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  #284  
Old 10-10-2016, 05:40 PM
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Brendan, I already got a whole bunch of sensor sockets from AliExpress. These ones. Unsure of the material...
I am not sure how to check if it is beryllium copper... any ideas?

Also I just noticed that Altronics is (mainly) Perth based, 3 out of 6 stores are in Perth. I could get the connectors for all of us and send them with the rest of the parts to you. I can get discount with our trade account and if don't have a local shop you could also save few $ on shipping.
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  #285  
Old 10-10-2016, 05:48 PM
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Faddy's comment from the Ukrainian forums:
Quote:
The capacitor C45, it is desirable to put more 20-30mkF 20B in the case in 1206, but they are hard to find. You can put in the body 10mkF 0805, will work.
So let's keep 33uF for C45 with 1206 footprint (I assume he meant 33uF and not 30uF).

Also this is quite important for once we start the assembly:
Quote:
Before installing the sensor, try to connect the output 3 DD3 DD4 with power (28 foot). It will be possible to evaluate the accuracy of the ADC and operatsionnika if noise StdDev (line) will not exceed 9, then you have a pretty good opamp and ADC.
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  #286  
Old 10-10-2016, 07:57 PM
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Quote:
Originally Posted by luka View Post
Brendan, I already got a whole bunch of sensor sockets from AliExpress. These ones. Unsure of the material...
I am not sure how to check if it is beryllium copper... any ideas?

Also I just noticed that Altronics is (mainly) Perth based, 3 out of 6 stores are in Perth. I could get the connectors for all of us and send them with the rest of the parts to you. I can get discount with our trade account and if don't have a local shop you could also save few $ on shipping.
That's excellent RE: sockets. Beryllium copper...jeeez that goes a long way back but I think it was a swab test sent for spectroscopic analysis. Problem is that its used everywhere, but really only becomes an issue when it becomes ingested and inhaled. Of course F111 pavetack and F18 FLIR used beryllium mirrors. It wasn't an issue unless "bird strike"...which happened once on an F111 mirror assy. All I remember is everyone ducking and weaving as to what to do and we were the depot repair so they dumped it on us and ran away!

If you mean should we avoid this material....I do not think it's possible as it indeed has its uses that cannot be replaced and indeed is usually not an issue unless it becomes a dust inhalant. Aka all the F18 hinged panels had beryllium copper contact fingers and pads. For a reason, it provides good conductive contact and spring tension as well as low corrosion and wear constraints. It wasn't an issue on the F18 until someone workout the main canon seal in the nose/pantograph area was a beryllium copper derivative and since this damn thing rotated and produced dust...my my what an issue!

Yes the preferred value is 33uF for the capacitor.

Altronics are in Vic...but alas not near me.

I was watching this on the Ukrainian forum but couldn't work out what they were saying. Good work indeed. Basically they are scaling the ADC prior to the sensor! Well done!

Brendan

edit: I have to say I have never purchased form alibaba but the Ukrainians and you have proved it to be ok ....maybe I'm too insular!
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  #287  
Old 10-10-2016, 10:10 PM
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Brendan, we want beryllium copper. Its thermal conductivity is much lower than copper (about 1/6 if I remember correctly) and this will significantly reduce the heat transfer from the PCB to the sensor via pins.
And, as you said, the chance of poisoning is virtually zero in the metal form.

Unfortunately the description on AliExpress only says
"material: metal"
Not very helpful.
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  #288  
Old 10-10-2016, 10:21 PM
perdrix (David)
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Peltier colling

Hi guys, have you chosen a Peltier cooler and fan yet? If so do you have the mechanical arrangements for fitting these defined?

Wish the original guys in Ukraine would provide more information on what they did for cooling.

I'm in two minds ATM as I have an EOS60Da, but of course that isn't cooled, whereas this would be and 6.1MP is not an issue for DSO work.

I'm working on getting a sensor right now.

Dave
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  #289  
Old 10-10-2016, 10:51 PM
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Hi David, Brendan has been playing with a Peltier from ebay but no decision has been made yet as far as I know. Everybody has been looking at the photos posted on the Ukrainian forums for ideas :-)
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  #290  
Old 11-10-2016, 01:58 AM
gehelem (Gilles)
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Hi gents,

just to inform on my nights to come :
I have 2 PCBs, and ordered my components at Mouser, with Patrice's BOM.
BTW : i can access to GDrive, thank you Brendan

Waiting time = Questions time :
Do you guys have a working board ? i mean, you're now talking about boxes and cooling options, but imho i would do first things first, ie having a working circuit, no ?
(sorry to be rude)

Gilles
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  #291  
Old 11-10-2016, 02:58 AM
pat30 (Patrice)
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Quote:
Originally Posted by luka View Post
Brendan, I already got a whole bunch of sensor sockets from AliExpress. These ones. Unsure of the material...
I am not sure how to check if it is beryllium copper... any ideas?
I bought these connectors, I can provide an answer, they are ferrous metal because they are attracted to magnets .

Can you send me the link to GDrive? although I soon finished (lack that DD7) I would see your changes.
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  #292  
Old 11-10-2016, 03:31 AM
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Patrice, can you PM me or Brendan your email address.

Gilles, we (few of us in Australia) don't have anything built yet. Brendan redrew the board and we are still thinking how to improve it to reduce noise. But basically the PCBs are ready to be ordered.

I already have all the parts here apart from few capacitors which we were are in the process of changing.

Now, several people have already built the camera and it works great. The proof of concept has been done so there is no doubt that we will need cooling sooner or later. That's why we are already thinking about the cooling and other aspects of the build.
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  #293  
Old 11-10-2016, 05:34 AM
gehelem (Gilles)
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Ahhhh, ok i didn't get that, sorry again
I admire those like you who are able to go further
I'm just a follower, trying to contribute by showing noobs like me can "just" follow
btw, Patrice, i've ordered the bigger g106 wich is 5,5cm.
We will see.
Gilles
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  #294  
Old 11-10-2016, 06:18 AM
pat30 (Patrice)
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with the large box, you can put any connections, example for ip67
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  #295  
Old 11-10-2016, 11:48 AM
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Just start to play with some TECs now a 40mm SQ (TEC1-12703) and 30mm SQ (TES1-12703). Problem is everyone would probably use their own HSFs so everyone's results may vary.

I expect the 30mm TEC to provide adequate cooling. We don't need to cool it to absolute zero...-5ºC would be adequate.
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  #296  
Old 13-10-2016, 01:57 AM
osult (Tom)
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Quote:
Originally Posted by luka View Post
Brendan, we want beryllium copper. Its thermal conductivity is much lower than copper (about 1/6 if I remember correctly) and this will significantly reduce the heat transfer from the PCB to the sensor via pins.
And, as you said, the chance of poisoning is virtually zero in the metal form.

Unfortunately the description on AliExpress only says
"material: metal"
Not very helpful.
Hi All,

I was looking at some ic sockets in Farnell which suggest the contacts are beryllium copper but after checking the product with manufacturer - it turns out only a small part of the contact is beryllium copper and the contact shell is brass - https://www.harwin.com/products/D8864-42/

The following is an alternative way to minimise the heat load transfer to the sensor:
Certain pins on ICX453AQ are repeated i.e. I think there are about 14 pins on the sensor labelled either Gnd or nc.
If all except for one of the pins on the ic socket corresponding to Gnd and NC are trimmed to prevent them connecting to the PCB and drawing heat from the board. The trimmed ic socket pins could then be connected together to the single remaining GND pin on the ic socket connecting into the PCB. The result is one pin connected to the PCB rather than 14.

Tom
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  #297  
Old 14-10-2016, 02:07 PM
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wasyoungonce (Brendan)
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Hi Tom I understand your idea but also think the sensor needs these common gnd points, not so much the N/C pins but the gnd is must.

On the subject of cooling...getting disappointing results with the 30mm SQ TEC. Supposed to be:TES1-12703
  • Voltage: 12V
  • Umax(V) : 15.4V
  • Imax(A) : 2A
  • Qmax(W): 27W
  • TmaxQC=0(C):67 (max temp diff between module sides)
  • Dimensions : 30mm x 30mm x 3.2mm
  • Red = +ve, blk = -ve. Writing (or red lead on right) = cold side
  • Suggested power = 12 x 2 = 24Watts. (ideal)
  • Actual power = 13.45 x 2.9 = 39watts (max measured)

I only got down to around 3ºC (2.5ºC min on cold heatsink) with hot side HSF at 32ºC max. Now the hot side is difficult to measure as the cooling fans is blowing on the probe which cools it and gives bad readings, but the HSF never got hot enough, with calibrated finger mk1.

The cold side had a small heatsink on it and I even placed the cold side in a plastic case to retain this cooling. Yet it reached min ~2.5ºC and went no further.

All this was done with an ambient ~22ºC, PSU 13.44V and max draw from 3A to 2.7A. No PWM just straight cooling. I did try some PWM with a motor controller and the results pretty much mirrored this.

Which tells me either I'm doing it wrong or this TEC is not working to specs....Hmmm go figure. I tried larger fans and HSFs all the same or even worse.
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  #298  
Old 14-10-2016, 03:50 PM
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Tom, I am not sure what disconnecting all ground pins but one would do to the sensor. While in theory it should be the same, for example those pins may be used internally to reduce the noise. There must be a reason why they are all ground pins and not NC (not connected) pins. But again, that is just a guess unless someone compares the sensor performance.

Brendan, it sounds like you are doing the right thing. What happens if you remove the small heatsink from the cold side? How could would it get without a heat load? I would expect for it to get covered in ice quickly.
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  #299  
Old 14-10-2016, 04:22 PM
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wasyoungonce (Brendan)
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Quote:
Originally Posted by luka View Post
Brendan, it sounds like you are doing the right thing. What happens if you remove the small heatsink from the cold side? How could would it get without a heat load? I would expect for it to get covered in ice quickly.
Actually I haven't done that yet I'll do so.

Brendan
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  #300  
Old 14-10-2016, 05:12 PM
pat30 (Patrice)
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Brendan, repeat the test but with 5 or 6 Volts power supply

Last edited by pat30; 14-10-2016 at 05:42 PM.
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