Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



DIY Thermal LPM for under $50

jib77

New member
Joined
Jun 19, 2010
Messages
718
Points
0
I found this stuff ... the words "Non-Reflective Finish" and "Ultra Flat Colors" were very attractive, so I got a can of black:



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

 



Xplorer877

Well-known member
Joined
Oct 24, 2008
Messages
1,060
Points
48
^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
 

Pontiacg5

New member
Joined
Dec 23, 2007
Messages
2,524
Points
0
Has anyone considered powder coating?

Can a TEC handle 425 degrees Fahrenheit for 15-30 minutes?
 

Xplorer877

Well-known member
Joined
Oct 24, 2008
Messages
1,060
Points
48
Has anyone considered powder coating?

Can a TEC handle 425 degrees Fahrenheit for 15-30 minutes?
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
 

JLSE

1
Joined
Dec 13, 2007
Messages
3,584
Points
0
Has anyone ever tried anything over 1 watt?

-Tony

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...
 

lazeerer

New member
Joined
May 25, 2010
Messages
3,664
Points
0
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.:)
 

JLSE

1
Joined
Dec 13, 2007
Messages
3,584
Points
0
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:
 

MarioMaster

Well-known member
Joined
Jul 27, 2007
Messages
3,643
Points
63
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:
I haven't had this issue with any of my tests, sounds like some component values are drifting in your system somehow
 

lazeerer

New member
Joined
May 25, 2010
Messages
3,664
Points
0
Here my LPM reading my 445nm laser.:D


:thanks:

Iam not having that problem now that it is calibrated.:)
 
Last edited:

JLSE

1
Joined
Dec 13, 2007
Messages
3,584
Points
0
I haven't had this issue with any of my tests, sounds like some component values are drifting in your system somehow

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:
 

Xplorer877

Well-known member
Joined
Oct 24, 2008
Messages
1,060
Points
48
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
 

lazeerer

New member
Joined
May 25, 2010
Messages
3,664
Points
0
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
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.
 

Xplorer877

Well-known member
Joined
Oct 24, 2008
Messages
1,060
Points
48
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
 
Last edited:

JLSE

1
Joined
Dec 13, 2007
Messages
3,584
Points
0
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.

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

I used a separate battery to power my volt meter.. I did not have this problem.

Good point, the ground cannot be common between the power for the circuit and input to the panel...
 
Last edited:

lazeerer

New member
Joined
May 25, 2010
Messages
3,664
Points
0
I used a separate battery to power my volt meter.. I did not have this problem.
 




Top