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Portable FAP Red

Hemlock_Mike

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Isaac --- I am still self employed and work on projects late at night. I should have something in about a week. The good laser is mounted to the fan heat sink and I need to make final resistor changes to the power control.
HMike
 



Alaskan

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I received the TI voltage regulator I ordered from that fellow I wrote to you about in the mail today, sure would like to see a schematic of what you have done with yours :) - No word yet if he has more ready to sell.
 

Hemlock_Mike

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Chris -- I'll try to get a drawing for you. I'm still trying to get the resistors for the voltage adjustment range working (Pin 20). The data page is pretty easy for most of the design --- many pins are either grounded or left open. I currently have 11K Ohms on pins 4 - 18 for a max current of ~ 35 Amps. Pin 21 to Gnd is my trigger using a NC switch. Everything will likely change a bit when I connect the good module.
HMike

I still can't send +Rep-------
 
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RedCowboy

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I have a pair of 20w arrays from junktronics that I never used, if you have any interest let me know.

 

Hemlock_Mike

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Chris --- Because the V/I curve of the laser is non-linear, I made my power control non-linear!! That is under control now.
My next concern is whether the diverging lens should have the concave side facing the fibers in the output of the module.
HMike
 
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Alaskan

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Great, getting closer. Looking forward with anticipation!

Mr. Mike dancing as he gets close to finishing his IR cannon :)

 

Hemlock_Mike

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Chris -- I like your Zumba too much!!!
I find that the module current rises as the heat goes up but applied voltage stays stable. I really want some feedback to the PS but it doesn't seem to work right.
Later -- HMike
 

Alaskan

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I have no doubt you know the reason, too small of a heat sink, fan on that small one can't keep up, obviously, your battery pack is doing well though. Hope you find a solution so you don't need a monstrous heat sink.
 

Hemlock_Mike

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Here's the wonder of breadboard design !!



I'll now mount the good laser and heat sink and do the final tweaking -- then the optics.
I'll try to get a schematic drawn this weekend. The resistor values may need to be adjusted for each application. I'm not using the remote sense connections because they didn't seem to respond the way I wanted. The battery pack is under the PS module - The PB switch is the trigger and the pot is obvious and the large red leads at the left connect to a key safety switch. I still am thinking of turning the plano side of the -FL lens toward the laser.
Chris -- I let the dummy load heat up to see how the diode bar responds and I know that I will limit this to 30 Amps. My values will change a bit because the 10 gauge wires will be shortened a bit in the final assembly.
HMike

PS: It really helps to have a resistor decade box for testing!
 
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Alaskan

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Cool beans, hope you can get something working in the not too distant future. Tonight I put a small 8 AH 2 VDC Cyclon lead acid battery on one of my FAP800's and shined it at a wall 25 feet away and saw a big red spot. Now I see why you say "red". It might be IR, but I saw a circle of cherry red light, very dim but also very red. The beam being a couple of feet wide is more like a spot light, but there it was. I don't think the color was an artifact, but how the eye responds to a 808nm IR source, but of course quite dispersed after expanding so much.
 
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Hemlock_Mike

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I AM BUMMED OUT. I mounted up the good module and put the factory lens assembly on it and hit threshold at about 15 Amps. A deep red spot on paper 10" away. I turned up the current to 25 Amps and ------- the spot turned yellow orange and I let go of the trigger. The output fiber port had burned :-( The same thing happened to my other 40 W FAP and in the same way. Can you believe the bad luck... I'm wondering if the output lens assembly is a problem or if the FAP is designed to be close coupled to a fiber cable and then the lens assembly.
I have removed about 1/8" of the coupler and have been polishing the "stump" using 1800 grit sand paper. At 5 Amps (below threshold), I can see all the fibers clean but I don't know yet how deep the damage went in the couple seconds.
I'm thinking an expander not connected to the unit might be a better approach.

Correct me if I'm wrong but I think I can still use the diode bar at 808nM to excite a NdYag rod -- I have a small one. All may not be lost.
HMike
 
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Alaskan

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Just received an answer to my email last week today, the said he was offline for a long time and just got my message, asked me how the one I just received from him a few days ago is working, but I'm not ready to try to test it yet. I asked him how many he has, no answer yet today. Last I heard he had 5 or 6, two of which are for you. He said three for fifty dollars last time we communicated about it though.
 

Hemlock_Mike

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I'm good for two units. They may be handy if 808 bars will
power up a NdYag !!!!!!
No More close focus on these FAP units for me !!!!!
HMike
I'm trying to get the module running again so I'm not
drawing a schematic. Those modules use many pins simply
for power and I only connect a few for the rest.
 
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Hemlock_Mike

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I got a "new" FAP today.....Tested ..............
I find 4 diodes in the bar DOA. It's going back - duh.
Hmike
 




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