ThermoElectric Coolers (TECs)

Yeah, the spec sheet sucks...there is so much information missing compared to other spec sheet I have seen. But what I do find food for thought is how easy it would be to make all of this portable. The peltier doesn't draw much current and now we know it doesn't require a huge heat sink.. ;D

This was another reason I ordered the block...it will make it much easier to mount in a flashlight, and also to replace the diode if it fails.

Gazoo said:

Yeah, the spec sheet sucks...there is so much information missing compared to other spec sheet I have seen. But what I do find food for thought is how easy it would be to make all of this portable. The peltier doesn't draw much current and now we know it doesn't require a huge heat sink.. ;D

This was another reason I ordered the block...it will make it much easier to mount in a flashlight, and also to replace the diode if it fails.

Click to expand...

I am absolutely heading toward portability. I plan on using two CR123s for power but am going to put them in battery holders rather than in a flashlight. I don't like the idea of someone picking up what they think is a flashlight and turning it on while looking toward the LD to see if the batteries are ok. I plan on a toggle and pushbutton switch for added safety.

Gazoo said:

Ok...now I understand. I have the same problem as you with no access to machinery, so I make do with what I have. I don't remember if I told you, or if you saw my post, but today I ordered another Meredith module and the mounting block. I already have one Meredith module and I wish I would have ordered the mounting blocks when I ordered it. Link follows:

w ww.mi-lasers.com/cgi-bin/shopper.cgi?search=action&keywords=diode_optics
(ed. link altered due to status)

I figure it is much easier to work with something square... ;D I will be using this for my next TEC project.

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You are a bad influence Gazoo. This hobby is getting to be like getting a free puppy. I just ordered the acryllic lens module with case adapter and mounting block.

;D Awesome. Following is a picture of a flashlight I configured for my Meredith module...it needs improvement and like I said having the mounting block will make it so much easier. It came with a drill set. I am powering it with four AA nimh batteries, am using a driver board I got out of another module, have an open can diode mounted in the module, and the module itself fits into the hole where the previous bulb came through. So all I needed to hold it there is an o-ring.

The reflector is made of metal and does help to cool the module. And the head of the flashlight rotates making it easy to aim and destroy.. ;D But I have noticed as the diode heats up, the focus changes. Cooling will correct this and as you can tell,there is ample room in this flashlight for everything.. The driver supplies 240ma to the diode.

that's a big flashlight! especially for a laser!

things said:

that's a big flashlight! especially for a laser!

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+1

--DDL

Daedal said:

[quote author=things link=1187495006/105#116 date=1188511086]that's a big flashlight! especially for a laser!

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+1

--DDL[/quote]

Nevermind...I will wait until I have completed my project then repost pictures of it.

JES (Jim)

Your post cracked me up ;D ;D I needed that Well said.

I don't care if you are in the push it to the max mindset. Please understand that you can make a weak LED in an instant. READ oops read read !!!

Mike

Hemlock Mike said:

JES (Jim)

Your post cracked me up  ;D ;D I needed that    Well said.

I don't care if you are in the push it to the max mindset.  Please understand that you can make a weak LED in an instant.  READ oops read read !!!

Mike

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Mike,

I do have my 'more power' mindset in but I am trying to prevent 'more power' blinders from developing.  That is why I am reading as much as I can on here and trying to find the safe upper limit.  I read a lot before I started posting.  The real questions are unanswered but they basically boil down to 'where is the sweet spot?'.  How much current is optimal for a particular setup's cooling ability?

Your slow max with Peltior cooling was very useful because it told us that there is no benefit to going over 400mA.  The chart on the spec for the diode is useful because it points out the great benefit of cool diodes and output.  In fact the chart shows a straight line relationship between current and output when the LD is kept at low temps.  What is off the scale of the chart is the area I would love to see.

What kind of output did you see when it was cooled all the way down and at 400mA current?  Did it increase much from 250mA or 350mA?  In your opinion, where is that sweet spot?  

Jim

Jim --  I'm working with three differend LD's now.... I'mgetting fergutfol in my old age !!
With the current GB diode, go for 250 mA for a start like mentioned elswhere.  For someone making a first laser.  STOP there  (oops stuck again!)  Enjoy and learn.

Pushing a LD to higher power involves using a power meter and other meters to graph the Po / Ild curve and find the knee where added current gives no more output.
Another way to see it is to carefully advance the drive and watch for the beam to start going crazy, bluring, mode hopping, whatever you see going wild ---  Back off.  Don't do this without monitoring the current and GOOD heatsinking ( or spare diodes!).   Running over limits posted elswhere on this forum will shorten diode life.  It's a real mix of power, lifetime and sudden death.
I don't recommend going over 250 mA.  That will give you a good laser and your diode may max out at 250 mA.  
That's why no one gives absolute settings -- every diode is different and that's part of this hobby      When you push to the max, you need to do the math.

Mike

Oh Yes !!!  What is "off scale" is for you to determine !!! Science at work.

and don't think about hooking them straight to batteries!your didoe could last a year, it could last a month, a week, or more likely a day, and very possibly instand death!

JES said:

[quote author=Gazoo link=1187495006/90#96 date=1188441482]
You are a bad influence Gazoo. This hobby is getting to be like getting a free puppy. I just ordered the acryllic lens module with case adapter and mounting block.

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I received my parts from Meredith today so you might get yours tomorrow. The mounting block is anodized red, and the block is aluminum...not brass. I will remove the anodizing before I glue on the peltier.

It does have a set screw to hold the module in place, the module just fits in the hole, so care was taken with tolerances. It also has two pre-tapped mounting holes just as described on the website.

I have always planned to use it with an open can diode, and to continue to use the Aixiz modules with the GB diodes.

I really did not expect to get this order until later next week, and I had planned to order a couple DVD burners over the weekend that I know for a fact have open can diodes. So as of this minute, I can not tell you how well of burner this will be compared to the one that comes with the glass lens. But I am impatient, so I will tear the DVD burner out of my computer later this evening and harvest the diode out of it.

gazoo stop pulling all the dvd drives apart ;D ;D ;D ;D so you want open can diodes?i pulled a ps2 apart and there was a open can in there. i knew it wasn't high powered though

;D Well this is the very first time I have had a diode fail after harvesting. Oh well...back the the drawing board, and ordering more DVD drives. ;D

Gazoo said:

I really did not expect to get this order until later next week, and I had planned to order a couple DVD burners over the weekend that I know for a fact have open can diodes. So as of this minute, I can not tell you how well of burner this will be compared to the one that comes with the glass lens. But I am impatient, so I will tear the DVD burner out of my computer later this evening and harvest the diode out of it.

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Just avert your eyes from the processor heatsink while you are in there or it might be weeks before we hear from you again...

I probably won't see mine until at least Wednesday of next week.  That is fine because SenKat doesn't yet have the GB LDs.  Unless he tracks down the order at the shipping center he is probably looking at Tuesday.  That means I wont have any LDs until next weekend.  I have the circuit parts but no peltior and no Aixiz modules.  I have learned patience.

I also took the opportunity of this project to refresh my electronics kit.  I ordered a new soldering station since my old iron was borrowed and not used properly.  I also picked up a new meter on general principals.  Neither of them is in yet either.

How long did it take your Peltior to arrive?  It has been about a week and a half since I bought it on eBay.  The guy lives in California so it really is not late yet.

Lol...well the way my computer case is designed it only takes a minute to remove or install a DVD drive. The open can diodes are a real bear to remove...I am going to try to find an easier way.

My second peltier took longer than the first one....I think it was 5 or 6 business days. If you don't get it by Tuesday, then I would contact the seller.

I am still very curious about the acrylic lens so stay tuned. I am going to swap the modules around in my "big" flashlight.