1500mW laser diode question

[boylesg]

If you turn this on with a 100% PWM then should you give it a rest period? If so how long?
Reason being that I am implementing a laser engraver and I have had to laser diodes permanently loose power (I think) after testing my software in a test run for a while.

 

[wwfeldman]

what is "this"?

please show a circuit and specify a part number for the laser diode

please explain this: "...laser diodes permanently loose power (I think) after testing my software in a test run for a while. "

 

[boylesg]

what is "this"?

please show a circuit and specify a part number for the laser diode

please explain this: "...laser diodes permanently loose power (I think) after testing my software in a test run for a while. "

When I first tested it there was smoke issuing from the MDF I was testing it on.

But now it doesn't seem to be able to burn the MDF.

Is there no general rule of thumb? Sorry but I am rather new to controlling lasers other than the 5mW ones.

This laser driver:
https://www.ebay.com.au/sch/i.html?....l1313&_nkw=laser+power+supply+board&_sacat=0

This laser:
**broken link removed**

 

[wwfeldman]

the ebay site has more than 100 different driver boards. which one do you have? who is the manufacturer?

without manufacturer data sheets, its hard to provide any useful information

"If you turn this on with a 100% PWM then should you give it a rest period? If so how long?" cannot be addressed without manufacturer data.

 

[boylesg]

the ebay site has more than 100 different driver boards. which one do you have? who is the manufacturer?

without manufacturer data sheets, its hard to provide any useful information

"If you turn this on with a 100% PWM then should you give it a rest period? If so how long?" cannot be addressed without manufacturer data.

Well I was hoping there would be a general rule of thumb for them.

As there are for LEDs......without knowing the specs of the LED is a safe assumption that any where between 10 and 25mA is a safe current.

 

[KlausST]

Hi,

Now you talk about LEDs....before it was a 1500mW laser.
This is totally different to a 20mA standard LED.

Klaus

 

[boylesg]

Hi,

Now you talk about LEDs....before it was a 1500mW laser.
This is totally different to a 20mA standard LED.

Klaus

You misunderstand me.

Not talking about LEDs.

I am talking about the rule of thumb with LEDs.

Is there a similar rule of thumb with laser diodes?
E.G. Run it at no more than 50% duty cycle for no more than 30 minutes......or whatever the case may be........and be reasonably assured the laser diode won't suffer damage due to heating.

Is there a reliably safe rule of thumb for laser diodes since I can't give you the specs for the specific diodes that I have in that laser module.

 

[KlausST]

Hi,

a "rule of thumb" is not safe. There as always a risk remaining.
The only really reliable information is written in the datasheet. ... even for LEDs.

Not every LED that "looks like" as standard LED will be a standard LED.
There also are LEDs:
* low current
* with built in resistor
* dual color
* with built in blinking electronics

... you won´t recognize it from outside.

****
Thus the "unreliable" solution (on your won risk) could be:
To look for datasheets of any 1500mW laser diodes and try to find out what´s the operation condition.

Klaus

 

[FvM]

The question makes no sense without a specification of the laser module. I presume you have at least a voltage/current/case temperature spec or are you finding the parameters by trial and error?

 

[boylesg]

The question makes no sense without a specification of the laser module. I presume you have at least a voltage/current/case temperature spec or are you finding the parameters by trial and error?

This is all I have. Looks like a manufacturer name at least. Neja? Mean anything to you?

Perhaps I am just going to have to trial and error this. Start off with 50% duty cycle and up it until it is just enough to burn my orange spray paint.

https://www.ebay.com.au/itm/NEJE-1500mw-405nm-Violet-Light-Laser-Head-High-Speed-For-DIY-Carving-Engraving/302803686401?epid=21021415296&hash=item4680819401&enc=AQADAAADAFjVrDbVsZ8oH%2F8PNHtt9VX4%2Fw7FZcmMuqsX8uaFEduVcd4JLlmY1l%2BORNVmSIRAFLIw2WnxUnJESRX9oh4PYUgM%2B2WfsncamhRKj7rVf0eeNa13KjQyrOdshe%2BPToG%2BsTMINj3FfnOEIyQj2nU73ac%2Bv5J0eOdTq1s34kkdUj6Yzlg6zt%2BkMW0P9smcbSu5mAzZvuY8bxM%2F8a1tkdzZrKL07WiumHst6PiBATt05Lx4k5mcwSLSoik7cxlR4nDcJv1LcFppOGp1Dm2d61v%2FvJMBPgXSjgiiJlwT4ZgppNIIh4j4iGs20eiSBjwyGGmAsYI5xafKRz%2FTZ6uBT%2F9pusDMEJ1XSKBJP7G0TQsyS3sVuAl9WNBev4s27GQ7mEQUwVECiUP1LthqKjyOo17u1iZyzxPytXcaDyx5vGJaGOv%2Fr%2Byl2q%2F5m4p47aFPzB5tFk7%2FL5jKD%2BcHttXtLSgOmCYU05qNaR%2FiwXJcD5WPBCJnbdOTop%2F6DJHZM7hkhxw%2F0GwXm1mfVIEhI9Opg3R3zzAzeHR9jmPrt%2Btg%2BJG2Q3Vx3cdTDzcU%2FwvkPrgFD2giqV4V%2BY4paCA%2FgUTfjikXkrEgcnl%2FGUFhHepEfySfYbpFPyaP%2FiBYSH75mZqVp%2B%2F%2FJGkXIi5cAcHznMVeCnyn8zroMbMr7B6%2Ft3cjNGV99eilm0CpAEAtGod8oc2uwRNBoP2axukFnnlh0PMt1x3m7DQlMB3KLNKNeAq5lszOcikxEAjoY%2BoW9zNuvRn0%2FdTFUBPBlsWhK2aLAH4nwrgbXuR5ASavQVLzhAJefvcDXMfeSZKjT6yf47aeZdUrjvESad%2BHXZjb7kKZgmgZ7GF8UtY0ShgLvRX%2FQPVIhLdqkcaTbVpQ573RsWoY%2FPB2sKevunFCltfvqmd7fgHwN6VJLhNhW9%2FSkW90K82NrenANDSJfwFI2B7jvtCqNyhBJBvPtMO1tpJc5X6qxbEAq%2Fm6nkgSxwTCoHGFdqmF4YXVeP6KIcP6bD1uI449oB3KNvneQQ%3D%3D&checksum=302803686401508d272a87d9476e8dcc3385b23d3a24&frcectupt=true

 

[KlausST]

Hi,

do you really need us to read the specifications from the given ebay page?
* Input voltage: 4.5-5V

Neja

no, --> NEJE

****
with an input voltage of 5V and a power of 1500mW this means about 1500mW/5V = 300mA
(But maybe 1500mW means optical ouput power, then the electrical input current is much higher)

Klaus

Maybe it´s something like: NICHIA NDV7375.
There are many discussions and the datsheet in the internet...

 

[boylesg]

Hi,

do you really need us to read the specifications from the given ebay page?
* Input voltage: 4.5-5V

no, --> NEJE

****
with an input voltage of 5V and a power of 1500mW this means about 1500mW/5V = 300mA
(But maybe 1500mW means optical ouput power, then the electrical input current is much higher)

Klaus

Maybe it´s something like: NICHIA NDV7375.
There are many discussions and the datsheet in the internet...

Well I merely posted the ebay product to show you what specs are available - not much.

Yes I came to the same conclusion and set my laser controller to just under 300mA and 5V out.

But I seem to remember reading some where, at some point, that you can't drive a laser diode at full power (100% duty cycle) for too long before you do damage to it.
But I have no clue as to specifics.

 

[KlausST]

Hi,

Well I merely posted the ebay product to show you what specs are available - not much.

To keep us busy? ;-)

But I seem to remember reading some where, at some point, that you can't drive a laser diode at full power (100% duty cycle) for too long before you do damage to it.
But I have no clue as to specifics.

This makes me assume you did not read the NICHIA datasheet....
I have already done the internet search for you ... was it a waste of time?

Klaus

 

[FvM]

But maybe 1500mW means optical ouput power, then the electrical input current is much higher

Surely, that's how laser diodes are usually specified.

I see that 4.5 to 5 V supply voltage is the only substantial spec at Ebay. I read the review of an apparently identical laser module, the author has measured the optical power and found it's only around 110 mW. He also had a spec that stated 1500 mW as electrical input. He mentioned that even for only 1500 mW input, effective cooling of the module would be necessary.

The overall assessment says fake specification.