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DIY Thermal LPM for under $50

I found this stuff ... the words "Non-Reflective Finish" and "Ultra Flat Colors" were very attractive, so I got a can of black:

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Result ... this has got to be the flattest paint Ive ever seen:

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^Looks good!

That Rustoleum paint is good stuff. Paint a piece of scrap metal or tile and try and burn it with a laser. It'll give you an idea of how careful you need to be with a exceptionally powerful laser.

-Tony
 
Has anyone considered powder coating?

Can a TEC handle 425 degrees Fahrenheit for 15-30 minutes?
 
Pontiacg5 said:
Has anyone considered powder coating?

Can a TEC handle 425 degrees Fahrenheit for 15-30 minutes?
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I doubt it. That'll melt the solder. Also doesn't powder coating leave a glossy finish?

There is no reason not to just use some high temp flat black paint. I just did one very thin, but through, coat and it's been great. As long as you don't focus them down to a point it will tolerate any power level <1 watt or so.

Has anyone ever tried anything over 1 watt?

-Tony
 
Xplorer877 said:
Has anyone ever tried anything over 1 watt?

-Tony
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I figured id take a stab at this meter to test my arrays which will be up to 6W.

I have calibrated against both my LB-I and LasrCheck, and am using the same TEC that the OP used in his (heruu. T-03 808 LD).

For the coating (in Canada, product names may vary from USA) Rust-Oleum Specialty High Heat from home depot. I applied 2 light coats for 1 uniform coat, then lightly dusted carbon black from a toner cartridge on the still wet paint coat, gently swabbing with a clean cotton swab.

I have not yet tested above 1.5W, but will be doing so soon. So far the meter is reading almost side by side with my LB-I which max's out at 1,390mW when the PC app is used.

I do prefer the speed of reading of my LB-I and the PC interface, but needed something that can take much higher wattage...
 
Tony, i have tested my 445nm its running at 1087mW .

It works just fine iam uploading a video right now will be up in alittle bit for you :).

I also used the stuff from homedepot the High Heat Rust-Oleum

When and if i bump my 445nm up i will let you know.:)
 
One thing I find with this meter is the readout constantly jumping around. I set to zero but it moves to the - by itself..

Is this also happening with your meters as well?? I made up a simple, single sided PCB and etched, but used the same values, so I dont think its an issue with my circuit.. Im hoping its the sensativity of the TEC..

I cant understand why it would drop by 10mW when I had zero'd it at room temp and withing a few mins after use have to zero again..?? :banghead:
 
wannaburn said:
One thing I find with this meter is the readout constantly jumping around. I set to zero but it moves to the - by itself..

Is this also happening with your meters as well?? I made up a simple, single sided PCB and etched, but used the same values, so I dont think its an issue with my circuit.. Im hoping its the sensativity of the TEC..

I cant understand why it would drop by 10mW when I had zero'd it at room temp and withing a few mins after use have to zero again..?? :banghead:
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I haven't had this issue with any of my tests, sounds like some component values are drifting in your system somehow
 
Here my LPM reading my 445nm laser.:D


:thanks:

Iam not having that problem now that it is calibrated.:)
 
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MarioMaster said:
I haven't had this issue with any of my tests, sounds like some component values are drifting in your system somehow
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If that were the case would the meter not do this as well when performing a reading? Example, to calibrate mine, I used a 650nm LD set to 100mW verified on to separate meters. I then Put the laser to my DIY LPM and the reading is rock solid for the most part, only drifting 5-7mW back and forth over an hour or so.

It could be that the thermopile is somewhat makeshift right now (solid alum. chunk), as I just set it up to test...

When I get it finalized I will see what happens. Its probably ambient temp related. The only runs ive done so far were really late / early morn. im sure it was something overlooked.

Nice project BTW MM +1 :san:
 
Since I zeroed mine it's never drifted. I'd say it's your pot.

Firgure out what resistance you need for the meter to zero and then just use a resistor. Mine needs about 24 ohms to zero.

Thanks for uploading the vid Lazeerer. I'm jealous your 445nm build is so powerful, my diode sucks! LOL!

-Tony
 
Xplorer877 said:
Since I zeroed mine it's never drifted. I'd say it's your pot.

Firgure out what resistance you need for the meter to zero and then just use a resistor. Mine needs about 24 ohms to zero.

Thanks for uploading the vid Lazeerer. I'm jealous your 445nm build is so powerful, my diode sucks! LOL!

-Tony
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Ever since i zeroed mine it doesn't go back and forth between 0 and 1mW anymore.:) Its stays at Zero.

Thanks, Iam sure you will get another diode soon and blow mine out the water.
 
Hey did you have any trouble with your voltmeter? I just got mine and it doesn't want to read the voltage. I checked that the output voltage is 0 or at least <2 volts with my VOM but then when I hook it up the voltmeter it displays 1, meaning an overload? WTF???

The voltage is ZERO and certainly not over 2 volts! It will measure the voltage of a AA just fine, 1.565v but again when I hook it up the volt panel input... "1".

Does it just not like the amplified output? Mario, is the output from the amp smooth? This is really stupid! :mad:

UPDATE:

K I figured it out. Apparently the meter does not keep the input and supply voltages separate. I think it uses the supply - as the ground for the meter. That's really stupid. I have to keep the meter voltage source separate form the amplifier voltage source. In other words I need two 9v batteries, one for the amp and the other for the meter, because for some idiotic reason it won't work with one. Now I need a DPST switch too. :wtf:

-Tony
 
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Does yours have jumpers on the back? I bought a panel locally and it was set for the low mV range by default..

Just a thought, though yours may be different.

Xplorer877 said:
UPDATE:

K I figured it out. Apparently the meter does not keep the input and supply voltages separate. I think it uses the supply - as the ground for the meter. That's really stupid. I have to keep the meter voltage source separate form the amplifier voltage source. In other words I need two 9v batteries, one for the amp and the other for the meter, because for some idiotic reason it won't work with one. Now I need a DPST switch too. :wtf:

-Tony
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lazeerer said:
I used a separate battery to power my volt meter.. I did not have this problem.
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Good point, the ground cannot be common between the power for the circuit and input to the panel...
 
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