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Disappointing experience with 445nm

jmgallego

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What is the voltage you are feeding the diode?
 



lasersbee

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I starting to agree with laserbees end hypothesis.

The driver is a Constant Current driver that has an IC to control the voltage while leaving current set a given level. I don't know if you call this linear, or what...
As I say again this driver on the lowest output setting is 200mA, which is below threshold for 445nm. It will run blu-ray fine and 650nm LOC diodes without busting a sweat.

DMM is a Voltage across the diode is approximately 5.0v @ 250mA, so it should be lasing instead it's a glowplug. (ie, it's popped)

Here is a 20x DVD LOC running off the same C.C.Driver. Output here is ~3.3v at 380-400mA.

This is a long exposure shot at 2.5sec
If your LD is hot as a "Glow Plug" then it is pulling a lot more
than 250mA.. Use your DMM and check the actual current...
You can do that safely by putting a 1 Ohm resistor in series
with the output of the Driver and the LD (either the Pos or
Neg side)..
then check the voltage across the 1 Ohm Resistor (1mV=1mA)

I'm betting your LD is pulling a lot MORE than 250mA...


Jerry
 
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Meatball

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DMM is a Voltage across the diode is approximately 5.0v @ 250mA, so it should be lasing instead it's a glowplug. (ie, it's popped)
5.0V? That's surprisingly high. That extra .4-.6V is going through the diode as heat, or straight damage to the diode. I say its a driver problem.

Try the LM317. It takes only a few minutes to put together, and is easy to set. That will tell you if it's the LD or the driver.
 

Seoul_lasers

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100% agree here :p I have mine at 1.4A and it takes a good ~45 secs before the heatsink gets warm :wtf:
Well, I did exactly what laserbee suggested to measure the current.

:shock: it's drawing WAY WAY too much current!!! WOw! Dammed near 2A worth. I'll be it's the initial load caused my driver to draw too heavy initially for the driver to handle and this is what caused the driver to spike and killed it.

:(

Cry. Time to use a new driver and get a new diode.

No 445nm demo for kids this summer. I guess we'll stick to 405nm and 650-660nm LOC.

I am still waiting on 3 of flamingpyros professional grade lab modules for what was to be a 445nm laser module, a 12x 405nm laser module and a LOC laser module. Also I will try and get a new driver.
 
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ossumguywill

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that sucks dude... I'm sorry about that.... and I'm going to agree with you, this hobby is a money drain. It's not actually that expensive, but the risk is so high that you end up paying twice as much as you though because things don't go to plan.
 

Seoul_lasers

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The host is a finned lab module typically used for 9mm diodes but this one is made for a 5.6mm diode. Several other people are using them for 500-600mW IR diodes. They are supposed to take some heat, but they obviously are inappropriate for driving 445nm diodes anywhere near 100% rating.

NO, flamingpyro's order was mixed up with something else. It hasn't been 3.5 weeks yet. SORRY. Nowhere near.

He is doing the best job he can with the huge workload.

SORRY AGAIN.

MY Fault. ::(:
 
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Flaminpyro

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Say it's not nice to to streach to truth to make someone look bad :mad: or is your sense of time just warped that bad :thinking: I'm a very busy guy, I help lots of people and have spent several hours trying to help you typing to you here so why is it you have to try and make me look bad by saying you ordered you HS's 3.5-4 weeks ago ?
Should I post here for all to see the date you sent funds to me to get on the list for machine work from my PP account, I'll just tell, it was 6-20-10 only nine days ago not 3.5 to 4 weeks ago :tsk:
Would you like your money back now ! or can you wait till I get to your order :undecided:




I am still waiting for Flamingpyo's slugs I ordered almost 3.5 / 4weeks ago. ( wait, has it been that long?)

hmm, what to do.
 

Seoul_lasers

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In Korea, 9 days = 4 weeks, so he's right. :na:
Right, we have a timewarp here in Korea because of all the nuclear testing to our North.
Kimmy's letting off some steam.

No, Flamingpyro is right. I have mixed him up with another order I have made.

Sorry.
 




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