60 WATT 808nm Build Log

MarioMaster · Dec 15, 2008

Basically just a teaser at this point, but it's on its way

Building will probably begin Wednesday or Thursday when I get home for xmas break and I can start working on the power supply

artix · Dec 15, 2008

MarioMaster said:
Basically just a teaser at this point, but it's on its way

Building will probably begin Wednesday or Thursday when I get home for xmas break and I can start working on the power supply

Don't forget the beamshots!

MarioMaster · Dec 15, 2008

Artix said:
[quote author=MarioMaster link=1229316479/0#0 date=1229316478]Basically just a teaser at this point, but it's on its way

Building will probably begin Wednesday or Thursday when I get home for xmas break and I can start working on the power supply

Don't forget the beamshots!

[/quote]

I'll probably be able to get beamshots on my IR camera without even a lens of any sort - this thing is a beast ;D

loneoceans · Dec 15, 2008

Yeah at that power you'll be able to melt some metal! Get it running soon!

chronos · Dec 15, 2008

I want to learn more about the PSU you're gonna use! I have a 40W coherent that requires 2.2v @ something like 50-60A !!!!

Cyparagon · Dec 15, 2008

Would wiring some computer PSUs is parallel (3.3V leg) with a massive power resistor work well?

chronos · Dec 15, 2008

You would have to find a computer PSU that is capable of giving that much amps on the 3.3v rail (usually shared with the 5v). I've found some that are capable of giving 40A, but most are between 25 and 35A. Now if you could somehow get multiple 12V rails together and output at the required voltage, you could get the required amps.

Check out those specs here: Enermax Infiniti, I think we could do something with that...

MarioMaster · Dec 15, 2008

You might be able to, but the 3.3v rail on computer psus aren't usually very large - I'm looking at a $100 700W power supply and it has a max of 29A on the 3.3v rail. I'm not sure if the supplies would like being put in parallel either :-/

I'm gonna be making a beefy linear power supply with a rewound microwave transformer, a 7 amp variac, three or four 25 amp bridge rectifiers, and 5x 16,000uf capacitors

Benm · Dec 15, 2008

Current sources can be coupled without any problem. So if you would have, for example 10 supplies with a 5 A current source each, those can be wired in paralel to provide 50 amps.

You could feed the current sources from a 5 volt power supply, though they would disspate a whopping 150 watts combined running at 50 amps into 2 volts. Wiring and building a bunch of current sources 5 or 10 amps each is however more manageable than a single one providing 50 amps.

MarioMaster · Dec 15, 2008

Yeah, making a huge wire-wound resistor would work but it would need a lot of cooling just for the resistor(s)

billg519 · Dec 16, 2008

Mariomaster -

I have the linear power supply setup you are going to make. It works very well for these diode bars. I have a variac powering a rewound MOT, rectified by a 150A bridge, a 20,000 uf cap with a 470 ohm resistor across it to smooth the DC. A current shunt with a digital panel meter attached to it give me current through the diode, and I also monitor the voltage across the diode. In the attached photo, I am powering a 60w 808nm diode bar that I have placed on a large finned heatsink. This diode did not come with a fac lens, so I fitted one myself. This messy looking test setup is a ferocious burner! I burnt a hole through a 4" ABS drainpipe in nothing flat and stunk up the house with the stench of vaporized ABS. I also burnt through a piece of corian countertop, this also smelled quite foul. It seems that to use this type of laser at home, good ventilation is needed.

In the photo, orange variac is at bottom center. MOT rewound with booster cable wire is on the left, connected to 150A bridge on large heatsink. The cap and it's attached discharge resistor (no blown diodes for me) are sitting on the heatsink for the bridge. The diode is mounted to the heatsink on the right, behind it you can see the current readout display. I think that I will build a decent copy of this power supply in a nice chassis.

You can use glass rods (solid) of different diameters as lenses, try different glass lenses as well as acrylic. I did blow up one cheapo glass lens that couldn't take the power, another good reason to wear the goggles! Bits of lens went all over.

mikeeey · Dec 16, 2008

I wonder... how bright 60W of IR appears to the human eye... BRIGHT IR? that's scary... cant you see an IR beam? how many mW of red does it look like? Would someone like to test for us? tell us what they observed? lol..

MarioMaster · Dec 16, 2008

mikeeey said:
I wonder... how bright 60W of IR appears to the human eye... BRIGHT IR? that's scary... cant you see an IR beam? how many mW of red does it look like? Would someone like to test for us? tell us what they observed? lol..

looking at a diffuse reflection would probably damage your eyes - I know I don't plan on doing it

billg519 said:
Mariomaster -

I have the linear power supply setup you are going to make. It works very well for these diode bars. I have a variac powering a rewound MOT, rectified by a 150A bridge, a 20,000 uf cap with a 470 ohm resistor across it to smooth the DC. A current shunt with a digital panel meter attached to it give me current through the diode, and I also monitor the voltage across the diode. In the attached photo, I am powering a 60w 808nm diode bar that I have placed on a large finned heatsink. This diode did not come with a fac lens, so I fitted one myself. This messy looking test setup is a ferocious burner! I burnt a hole through a 4" ABS drainpipe in nothing flat and stunk up the house with the stench of vaporized ABS. I also burnt through a piece of corian countertop, this also smelled quite foul. It seems that to use this type of laser at home, good ventilation is needed.

In the photo, orange variac is at bottom center. MOT rewound with booster cable wire is on the left, connected to 150A bridge on large heatsink. The cap and it's attached discharge resistor (no blown diodes for me) are sitting on the heatsink for the bridge. The diode is mounted to the heatsink on the right, behind it you can see the current readout display. I think that I will build a decent copy of this power supply in a nice chassis.

You can use glass rods (solid) of different diameters as lenses, try different glass lenses as well as acrylic. I did blow up one cheapo glass lens that couldn't take the power, another good reason to wear the goggles! Bits of lens went all over.

thanks for showing your project, looks like what I'm doing should work well enough

mikeeey · Dec 16, 2008

lol.. but in all seriousness, would shining it into the night sky and looking for a beamshot be dangerous? is there such thing as too bright of a beam?

Switch · Dec 16, 2008

Benm · Dec 16, 2008

mikeeey said:
lol.. but in all seriousness, would shining it into the night sky and looking for a beamshot be dangerous? is there such thing as too bright of a beam?

I depends on conditions really. In clear air, not that much should reflect back considering rayleigh scattering is less efficient with wavelength. But if its a bit foggy, you should probably beware. I'd say the best approach would be to wear goggles yourself, and take beamshots using the digital viewfinder on your camera - that should show the beam clearly.

And at 60 watts, you can be sure looking at the dot reflecting of someting IS dangerous.

I wonder... how bright 60W of IR appears to the human eye...

Well, compared to say 650 nm, 808 is about 1/1000th the visibility or something in that order. With those figures it should appear as bright as a 60 mW red, but seriously damaging your eyes and probably setting on fire whatever you point it at.

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