Laser Retrofit Light Bar

[Fiddy]

G'day,

Its been a very long time since ive returned to this forum, theres been large leaps and bounds in output power since I was here last!

My other hobby (hunting) has led me back here, as hunting at night has me using darker red lasers for spotting feral game as they either cant see it or a confused by it.

I built a 770mW 670-690nm back in 2012 utilizing a T03 package diode and plonked it in a big hand held:

https://laserpointerforums.com/threads/ultrafire-uh-t60-to-3-670-690nm-class-4-handheld.77117/

I havent seen many powerful 670nm+ diodes lately?


There has been some interest among my mates that we should utilise a few red lasers defocused for scanning hills covering a largish area, mainly for locating foxes, this will be mounted on a offroad veichle.

So ive come up with bit of a design to drive 4x ML562G84 2.5W diodes in series, their multimode angle is kind of perfect for scanning hills, I plan on angling 2 diodes facing straight out the front and the outer 2 diodes 20degress to the sides.

Ive purchased a cheap 10" light bar and am in the process of desiging and printing a holder for some heatsinks, and depending on the duty, TECs under each heatsink to transfer heat to the light bar body.

My questions are, what lens would be most suited for this? Generally back in the day i would use a G2, im not going for beam quality of a 3 element glass so thats out, would it be worth using a G8? Are they the best for transmittance of 638nm

Would the clear plastic cover over the light bar melt at ~2W passing through?

Cheers, Fiddy.

 

[SĤ𝕒∂όⓦŁ𝔸ŜєR]

I believe that the plastic I see in the photos is a polymethyl methacrylate (PMMA), so it tends to reflect the laser beam, regardless,
Of the power and consequently could slowly melt the black body, you can make holes in the plexiglass in such a way as to make,
The laser beam shoot out, without hitting the plastic. [IMO]
What are the properties of your PETG?
Brand, details, do you have any? There are many types of Polyurethane-Glycolate , what infill percentage did you have use?

 

[Fiddy]

I believe that the plastic I see in the photos is a polymethyl methacrylate (PMMA), so it tends to reflect the laser beam, regardless,
Of the power and consequently could slowly melt the black body, you can make holes in the plexiglass in such a way as to make,
The laser beam shoot out, without hitting the plastic. [IMO]
What are the properties of your PETG?
Brand, details, do you have any? There are many types of Polyurethane-Glycolate , what infill percentage did you have use?

Thought that might be the case, i might run without the clear cover.

PETG is a tougher ri plastic than PLA, UV resistant and a bit high temp handling, i use ESUN PETG its decent stuff.

Im also considering mounting a 25x25mm square alloy bar thats the same length and mounting it instead of the plastic, it will offer great cooling i think.

Printed the holder fine, made 2 of the 4 heatsinks today.

 

[SĤ𝕒∂όⓦŁ𝔸ŜєR]

Thought that might be the case, i might run without the clear cover.

PETG is a tougher ri plastic than PLA, UV resistant and a bit high temp handling, i use ESUN PETG its decent stuff.

Im also considering mounting a 25x25mm square alloy bar thats the same length and mounting it instead of the plastic, it will offer great cooling i think.

Printed the holder fine, made 2 of the 4 heatsinks today.

Yes eSUN is a good brand of filaments, to give a look to the whole thing you could have also used PETG-C or carbon loaded, or a PETG or ASA carbon effect, however it is better that you put the bar in aluminum alloy, PETG resists UV and also high temperatures, but with lasers already from 2W, it is not good, because it "resists" the heat but does not "dissipate" it and for lasers you need heat dissipation, not retention of the same! if you are good with polycasting you can also make from your printed object, the equivalent in aluminum, many do it, at least you have a unique piece and you do not have any problems.
Or apply Noctua fans to ventilate the lasers, as a last change.

 

[Fiddy]

This is true, I printed the heatsink holder for the set angles of the side facing beams.
the 25mm OD heatsinks seem to handle the heat quite wll for now, the heatsinks wont be getting near the warping temp of PETG.

Recived 5x USHIO HL63193MG 700mW in the mail today pretty impressive at 1A, ill series 4 of them up and run them all soon.

Attached is th scehmatic ill use, using LM2596 3A constant current modules as a driver.

 

[SĤ𝕒∂όⓦŁ𝔸ŜєR]

Great job

 

[Fiddy]

Great job

Thanks!
ive installed all 4 diodes and machined all the heatsinks quite the show with 4 on at once!
i think they are G2 lenses, not sure.

 

[SĤ𝕒∂όⓦŁ𝔸ŜєR]

Thanks!
ive installed all 4 diodes and machined all the heatsinks quite the show with 4 on at once!
i think they are G2 lenses, not sure.

Cool, to see if they are slow G-2 points the beam of one of the 4 red lasers at a fixed point and takes a picture of what you see where the beam lands, a circle or an elongated rectangular strip?

No way .. man, the bar printed in PETG starts to warp in the points where the hex-head threaded screw is then fixed... I told you... the heat also melts the PETG, 2W is a lot, even if dissipated by aluminum rims, in any case the rim overheats.

 

[Fiddy]

Cool, to see if they are slow G-2 points the beam of one of the 4 red lasers at a fixed point and takes a picture of what you see where the beam lands, a circle or an elongated rectangular strip?

No way .. man, the bar printed in PETG starts to warp in the points where the hex-head threaded screw is then fixed... I told you... the heat also melts the PETG, 2W is a lot, even if dissipated by aluminum rims, in any case the rim overheats.

its mainly a bar output from these multimode diodes. Ill get everything mounted proplerly and get some longer distance beam shots.
we will see how well the petg handles the heat.

 

[SĤ𝕒∂όⓦŁ𝔸ŜєR]

its mainly a bar output from these multimode diodes. Ill get everything mounted proplerly and get some longer distance beam shots.
we will see how well the petg handles the heat.

Ok , i'm wait your update

 

[Thefudger]

I thought that you couldn't wire laser diodes in series. Have you done this before with good results?

 

[RedCowboy]

The same diodes, YES, works very well, all the N1h1a arrays are strings in series.

You can also get decent efficiency with a simple linear regulator with many diodes in series, I was running all of these off of a single lm338 configured as a current limiter.
If your laser diode needs 2A @ 5V and you have 10 laser diodes in parallel, then you need 20A @ 5V.
But in series you need 50V @ 2A for the 10 diodes.
It's actually safer to run in series because inconsistencies could cause 1 diode to draw more than another if in parallel, but in series that's not an issue.

Thread 'Multiple beams'

Apr 26, 2020

Sheltering in place and being somewhat bored I bought a used projector for cheap with 2300 hours and harvested 24 x M-140 diodes that work very well, I am driving 4 laser diodes in series @ 1.6a using a LM338 as a current regulator using 0.8 ohms across the adj. and output pins and 8 x 18650 in series,.....my expideted mounts are angle brackets giving me X and Y adjustment so I can converge the beams where ever I want to.........thinking about what else I can do with all of these diodes.......maybe knife edge a bunch ? Anyway just goofing around and thought I would post a couple of...

• RedCowboy
• Replies: 70
• Forum: 445nm Lasers

• 
• 

 

[Thefudger]

The same diodes, YES, works very well, all the N1h1a arrays are strings in series.

You can also get decent efficiency with a simple linear regulator with many diodes in series, I was running all of these off of a single lm338 configured as a current limiter.
If your laser diode needs 2A @ 5V and you have 10 laser diodes in parallel, then you need 20A @ 5V.
But in series you need 50V @ 2A for the 10 diodes.
It's actually safer to run in series because inconsistencies could cause 1 diode to draw more than another if in parallel, but in series that's not an issue.

Thread 'Multiple beams'

Apr 26, 2020

Sheltering in place and being somewhat bored I bought a used projector for cheap with 2300 hours and harvested 24 x M-140 diodes that work very well, I am driving 4 laser diodes in series @ 1.6a using a LM338 as a current regulator using 0.8 ohms across the adj. and output pins and 8 x 18650 in series,.....my expideted mounts are angle brackets giving me X and Y adjustment so I can converge the beams where ever I want to.........thinking about what else I can do with all of these diodes.......maybe knife edge a bunch ? Anyway just goofing around and thought I would post a couple of...

• RedCowboy
• Replies: 70
• Forum: 445nm Lasers

• 
• 

That is very neat. I totally expected the 50 volts to fry the diodes, but I suppose it does make sense that one wouldn't take it all and perish

 

[SĤ𝕒∂όⓦŁ𝔸ŜєR]

The same diodes, YES, works very well, all the N1h1a arrays are strings in series.

You can also get decent efficiency with a simple linear regulator with many diodes in series, I was running all of these off of a single lm338 configured as a current limiter.
If your laser diode needs 2A @ 5V and you have 10 laser diodes in parallel, then you need 20A @ 5V.
But in series you need 50V @ 2A for the 10 diodes.
It's actually safer to run in series because inconsistencies could cause 1 diode to draw more than another if in parallel, but in series that's not an issue.

Thread 'Multiple beams'

Apr 26, 2020

Sheltering in place and being somewhat bored I bought a used projector for cheap with 2300 hours and harvested 24 x M-140 diodes that work very well, I am driving 4 laser diodes in series @ 1.6a using a LM338 as a current regulator using 0.8 ohms across the adj. and output pins and 8 x 18650 in series,.....my expideted mounts are angle brackets giving me X and Y adjustment so I can converge the beams where ever I want to.........thinking about what else I can do with all of these diodes.......maybe knife edge a bunch ? Anyway just goofing around and thought I would post a couple of...

• RedCowboy
• Replies: 70
• Forum: 445nm Lasers

• 
• 

But can they be collimated into a single powerful beam, by applying mirrors, made of the same compound as the single G2 lenses?
In such a way as to absorb only 4% of the power?

 

[RedCowboy]

You can knife edge beams and yes your front surface mirrors need to be kept clean, otherwise they will rob power, but better yet is to use dielectric coated reflectors and again keep them free from dust/smoke contamination.

Prism Mirror

www.live-lasersystems.net

Pardon Our Interruption...

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That is very neat. I totally expected the 50 volts to fry the diodes, but I suppose it does make sense that one wouldn't take it all and perish

Each diode will get an equal division of the voltage, so @ 50V each of 10 diodes will get 5V when in series, that's provided the necessary current is there to flow 5V each.

Remember laser diodes need current regulation to prevent runaway as they warm up, always regulate the current.

So for our 10 diodes in series, if the driver has 50V available and the current is limited to 2A at which 5V ( example NDB7875 ) will flow through each diode, then each diode will only get 5V..... however if you limited the current to say 1.25A then each diode would only flow the voltage needed, say 4.35V each even though 50V was available.

 

[SĤ𝕒∂όⓦŁ𝔸ŜєR]

Would the colored mirrors The neutral ones be the dielectrics?