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Portable FAP Red

Hemlock_Mike

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A moment of true brilliance !!! Reach up to adjust the power supply and hear the power module go SNAP -- not even any smoke :-( What a dumb ass moment for "Mr.Magic". Oh well -- for $70, another is on the way...
HMike
 



Cyparagon

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Why did it die? I hope you're not going to put another one in without finding out first.
 

Alaskan

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I should let him tell the story, but he doesn't come back to the forum for days at a time, sometimes. I happen to know what happened after talking with him tonight on the phone, he accidentally turned the input voltage up too much going into the regulator, has a new one on the way already.
 

Hemlock_Mike

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That is correct. I turned up the power supply to 25 volts without watching the right meter. I was watching the other three meters. Expensive brain fart....... Fortunately, the good FAP unit was not connected.
HMike
 
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Alaskan

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I found a guy who sells these TI 48 amp regulators as pulls for 25 dollars each, maybe less if I can order up to six from him. He says they are coming out of servers which were working, so should be good and guarantees they work.
 

Hemlock_Mike

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Chris -- I'm interested - What's the part number? I hope the pin out is like mine.
I got the new module installed tonight with a small foible -- Bad eyes :-( I drove a phlat LED to about 4 amps and decided to go to bed happy.
I redesigned the battery pack and will mount the PS on its back.
Guys -- This high current stuff needs understanding of IR losses in connections. Jap clip leads will mess up everything if you don't understand them. I use them for current limiting in set up testing.
HMike

Chris --- Many of these power units can be run in parallel for more current if connected correctly. I have mine limited to 2 VDC output, variable between 1.34 and 2 VDC output (I hope)............
It's too damn cold to work in my machine shop tonight.

PPS -- These power modules may be what LED experimenters also need for Phlat flat whatever LED modules. They are quite efficient using buck mode.
 
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Hemlock_Mike

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I'm in for 2 units!! they are super for high current if you understand that they are CV and NOT CC. Maybe others here will join the deal. Make sure that they are the WAD suffix so they aren't surface mount. -- Later -- The WAZ mod looks like through hole design - so OK.
HMike

If you get some, I'll have to draw my circuit for you. I still don't understand the -Sense part but the damn clip leads will be scrapped soon.
 
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Alaskan

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OK, lets see what he says, I asked for a price for three and six. I'd like three, with your two that leaves just one remaining unless he can find more. Edit: Yes, I understand they are CV, if I set the voltage somewhere between 1.8 to 1.9 VDC out I should get at least 30 watts out of my FAP.

If these regulators are 95 percent efficient, and I use them with 12,000 mA/12 AH of Li-ion battery capacity at 8.4 VDC, at 25 amps of draw at 2 VDC from the regulator, I'm expecting to only draw roughly 25% or so of that amount of current from the 8.4 VDC series parallel battery stack, or a bit more than six amps, that ought to allow the battery supply to last a long time. Initially, I was thinking the Enersys Cyclon 2.0 VDC lead acid battery was the way to go, but that will only last 15 minutes at full power with their 25 AH battery drawing 40 some amps and that battery is heavy, using a stack of series-paralleled Li-ion batteries is much lighter, more compact and will have twice the run time when pushing the FAP harder than 30 watts of output pwer, not that I'd run it anywhere near that long, it is good to have the capacity so recharges aren't needed so much.

This switching regulator, even if it isn't CC, is a better way to power the FAP800 than straight off the battery at 2.0 to 2.1 VDC, as long as I don't run it harder than 30 watts out which is 2/3 its full rating and keep the voltage down below 2 VDC. Using a conservative duty cycle with good heat sinking in the past, I never saw the current creep up when using a lab power supply set to 2.1 VDC (without setting a CC limit), so I don't expect it will have a problem this way either.

Looking at the specs, it doesn't appear I need to worry about noise spikes, but have you scoped the output when you turn on the regulator?
 
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Alaskan

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Hmmmm. I think you are correct about the far field issue, but Mike isn't interested in that, as I am. I do have a single emitter 808nm @ 16 watts output in a C-mount package, perhaps I should use that instead.
 

RedCowboy

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Hmmmm. I think you are correct about the far field issue, but Mike isn't interested in that, as I am. I do have a single emitter 808nm @ 16 watts output in a C-mount package, perhaps I should use that instead.
If it has the tiny FAC lens then you are ready to go. Just do your concave convex expander preferably AR coated and your off to the races.

We must remember to enclose anything we build if we are the only ones wearing eye protection, a partial reflection off a lens at higher powers could be devastating, but you know that. :)
 
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Alaskan

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Yep, it has a FAC, supposed to put out a square shaped beam.
 

Hemlock_Mike

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This has become an interesting melting pot
of ideas. That should be what LPF is about !!!
HMike

I'd like to add some +rep but I can't --
consider yourselves plused.
 
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Hemlock_Mike

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Latest and greatest......



These are the assemblies which will fit in a 3" PVC pipe.
From the left, I have the Laser module mounted on a fan cooled heatsink. Next is the power module mounted over
the 3 cell pack. This assembly shown is about 9" long. Remember that I don't have the expander mounted here.
I changed the cell holder from my original plan to better utilize the available space.
HMike
 
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Hemlock_Mike

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I got the cell pack and TPH module mounted together as a unit tonight. Without clip leads, the unit will easily exceed 40 AMPS into the broken FAP dummy load. I need to change my limiting components to prevent damage to the good unit.
At 30 Amps. nothing seems to get hot except the laser module... The #10 Gauge wires, 8" long each, drop 0.15 VDC at 30 Amps. I need to adjust my MAX voltage components to limit the current.
HMike
 
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