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NUBM44 6W+ 450nm Laser Diode




CurtisOliver

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Yes, he doesn't directly drive the diodes. You must use a laser diode driver in future rated to the specs of the diode. DTR makes it incredibly easy for you as he usually recommends what driver to use. Even better still he has eBay listings with the driver already soldered up so all you have to do is wire up the dc power supply to the driver.
 

Eracoy

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CurtisOliver

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On that page, he is using a DC power supply, but in current-regulating mode (the red light by the word "current"). This allows the DC power supply to act as a driver directly passing regulated current to the diode.
I thought DTR always attached a driver on for those tests. Maybe I'm wrong.
 

wdimitry

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On that page, he is using a DC power supply, but in current-regulating mode (the red light by the word "current"). This allows the DC power supply to act as a driver directly passing regulated current to the diode.
That's exactly what I used.
The red light by the word "current" means that current is flowing through the wires - something is attached and working.

Now the light from diode is fading after 1 second of work. Hm, how could I have burn it up even with heat sink... It was working only 20 seconds
 
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CurtisOliver

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I never thought those DC power supplies were stable enough to run diodes alone. We need to DTR to pipe up if he is around.
 

Atomicrox

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Of course you can use a bench regulated supply to power diodes directly. A driver is, after all, a miniaturized constant current supply.
Some caution is needed, though:
-Use a good supply without significant spikes and good regulation
-Have the psu on, at 0V 0A before connecting the diode
-Touch positive to negative before connecting the diode
-After connecting turn up the voltage and only then turn up the current, taking care to avoid overshooting
 
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paul1598419

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Curtis, DTR has always used a voltage and current regulated power supply to show the current the diode is using to produce the power it is putting out. This has been his procedure for years.
 
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CurtisOliver

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Thanks, I always thought he tested with the driver as well. Now I know different. :p

Edit: Totally ignore me. Makes perfect sense when I look closer at the voltage/current readings done by DTR. They match the diode inputs, not the driver inputs. Guess I never really paid much attention to it as I buy my modules with the driver already set.
Anyway, surely you must have to have a relatively stable power supply (like DTR's) still in order to keep the current within the tolerance. Or am I wrong on that too. :p
 
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paul1598419

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I know Alaskan has driven some of the single mode 520nm diodes without a driver as the Vf is right at or above the voltage of a fully charged Li-ion battery. He has said that it works fine and has never lost a diode doing this. But, it is an exception to the rule.
 

Atomicrox

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Thanks, I always thought he tested with the driver as well. Now I know different. :p

Edit: Totally ignore me. Makes perfect sense when I look closer at the voltage/current readings done by DTR. They match the diode inputs, not the driver inputs. Guess I never really paid much attention to it as I buy my modules with the driver already set.
Anyway, surely you must have to have a relatively stable power supply (like DTR's) still in order to keep the current within the tolerance. Or am I wrong on that too. :p
It has to be stable, but doesn't take a professional tool. As long as it isn't a cheap Chinese switched-mode PSU it'll probably work.
 

RedCowboy

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That's exactly what I used.
The red light by the word "current" means that current is flowing through the wires - something is attached and working.
WRONG, that's not what it means, it means your current is limiting, when you reach 4.0 amps or your target you should turn the voltage down slowly until it lights up indicating it is in regulation too.
But power supply's are crude and should not be used to turn on a diode as if they are pre set, you must start over each time and turn them up slowly, they are not meant to be drivers.

You could have an intermittent connection and that is all you need to blow a diode if you start turning up your voltage then bringing the current up, you should chase one closely with the other from zero working back and forth, that way if you have a break in your circuit your PS wont spike very hard.

 
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DTR

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Curtis, DTR has always used a voltage and current regulated power supply to show the current the diode is using to produce the power it is putting out. This has been his procedure for years.
Yes I have found it is a very easy way provide a great visual representation of the power curve of a diodes. Direct driving can be done but there is risk. I don't suggest direct driving specially to those without a lot of experience doing so with laser diodes on the equipment they have and who accept the risks associated with it.

It is really only ideal for initial testing and only if the only options to get the test info you need due to having to follow a process every time you want to power it up or down. Even I have a countless number of fallen soldiers from direct driving. It was more common with my old china mastech supply for random killing specially toward the end as I think the pots were wearing out sending transient surges as I turned the dials so I bit the bullet and got what I think is a pretty decent unit now but it still has a small body count on it. Every supply has it own quarks that you have to learn but really for diodes I have lost it is mostly from my brain freeze moments and doing something stupid in a fraction of a second that usually leads to a few minutes of kicking myself and them moving on.

Anyway is it is very easy to either make a split second mistake in process or via quarks of the supply that can damage laser diodes which is why I don't suggest them and in the end any project will need a laser driver as using a power supply to direct drive is not a good permanent solution. Most scenarios there is no reason not to just start with using a laser driver.



Of course you can use a bench regulated supply to power diodes directly. A driver is, after all, a miniaturized constant current supply.
Some caution is needed, though:
-Use a good supply without significant spikes and good regulation
-Have the psu on, at 0V 0A before connecting the diode
-Touch positive to negative before connecting the diode
-After connecting turn up the voltage and only then turn up the current, taking care to avoid overshooting
Yes this is a good way to minimize some of the risks of direct driving and to add to that before power cycling or disconnecting the diode turn both the voltage and current back to zero.

The risk of spiking a diode is greatest during a power cycle or going from no load to load or load to no load with a potential as in having the voltage or current not set to zero. A nice secure connection should be maintained.
 

paul1598419

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This is the reason I invested in some good contact cleaner some years ago to clean noisy pots and switches. I was having some trouble with some noisy pots on my scope and several years ago tore it apart and cleaned every pot and switch on it. You'd be surprised how well it works.
 

wdimitry

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Ok. It appears that my brand new nubm44 is now dead and could work only in pulse mode. sad.
Looking for the solution I've found this setup:

15W Laser Head Engraving Module Metal Marking Wood Cutting For Engraver +Adaptor | eBay

It claims to be 8W engraving device with everything you need included. However the fact it is a Chinese market sounds a bit unreliable.
What kind of diode they use to get 8W, how do you think?

Would it be better to use nubm44 with driver and optics and construct such a device yourself out of it?
 

RedCowboy

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I would go with DTR's set up, including his recommended driver, that Chinese thing is going to overheat I would bet.
 




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