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CRX says Hello.

CRX

Member
Joined
Sep 16, 2019
Messages
21
Points
13
Hello LaserPointerForums,

I am CRX from Scotland, some of you may know me from the flashlight forums already.
I like to modify and make torches by hand using only simple hand tools. I now have an interest in lasers too so I'm probably in the right place here ;)
Here's an example of my handiwork. Stratis Lumina Copper & rosewood flashlight.
cBmNYVs.jpg

I know a bit about building flashlights but not so much the intricacies of lasers so have been crash reading the past few days, nice site you have here
with a wealth of information and friendly considerate people (y)
I will contribute what I can until I am up to scratch with the way of things.
I have seen a lot of nice work that I like so far, especially the more compact builds.

I have some parts for my first real build ordered, along with some decent safety glasses of course and will no doubt have some questions
you have heard many times before but you're a helpful bunch and I promise I searched first, honestly! :D

I have some experience with the low powered red lasers and a couple of 20mW & 50mW greens.
I thought I would start off with the mid range Osram PL TB450B 1.6W 450nm blue laser diode coupled with a single Li-Ion cell adjustable
0-1600mA boost driver and 3-Element collimating glass lens assembly.
From what I have read, this should give a slightly better beam at the cost of some output. I could not source a G8 lens in this country.

Questions: (Hope it's ok to ask here, let me know if I should start a thread or just search more!)

As the driver shouldn't really output more than this diode can handle at any selected output are there any special concerns before soldering up
or switching on for the first time?
I see DTR tested this diode to 2.5A but recommends no more than 1.8A supply current. Do I need a dummy load setup here at all?
I think I read about shorting the driver output terminals to get rid of any capacitance charge before applying to the diode?

I understand this diode is case isolated?

Is is ok to adjust the current pot on the driver with the setup powered up or should I adjust only when powered down?

Can I run the diode at any output level, say 500mA, or 1000mA or should I only aim for the diodes maximum tolerance?
Anticlockwise for power up?

Driver:
XmQUpka.png


Thanks,

- stevi -
 
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Anthony P

Well-known member
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Oct 7, 2018
Messages
529
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63
A dummy load is a critical step and should not be omitted. Laser diodes can operate over a range of inputs. On the data sheet for the diode it will have a threshold value for current. This is the lowest current required to make the diode lase instead of just lighting up. I always to stick to manufacture recommendations for max current. Many people run the diodes higher than max at the cost of shortening its lifespan. To overdrive, look into "knee". This is the point at which increasing current to the diode no longer increases optical output... the curve flattens out.

Hope this helps.
 
Joined
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Welcome to the LPF. Laser diodes are only driven by current limited drivers, so they need to be setup for a maximum current before you use one with a laser diode. Red diodes tend to have very low forward voltages, so boost drivers are not the best for these diodes. Buck drivers are better for red diodes. Good luck with your first build.
 

BowtieGuy

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Welcome to LPF, CRX! :)

Have fun, be safe, and enjoy your stay.

BTW - Nice custom work.
 
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CRX

Member
Joined
Sep 16, 2019
Messages
21
Points
13
Thanks very much for the help and welcome (y)

Here's what I made:
CRX CuTi Blue Laser Osram PLTB450B 450nm 1600mW - OFBD 1.6A - 10280 - Mo Button & Twisty Tail Sw - 1600mW.
CRX CuTi Laser Osram PLTB45B 450nm 1600mW - OFBD 1.6A - 10280 - Mo Button & Twisty Tail Sw - 1600mW.

CRX CuTi Laser Osram PLTB45B 450nm 1600mW - OFBD 1.6A - 10280 - Mo Button & Twisty Tail Sw - 1600mW.

CRX CuTi Laser Osram PLTB45B 450nm 1600mW - OFBD 1.6A - 10280 - Mo Button & Twisty Tail Sw - 1600mW.

EaglePair Safety Glasses.
 
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