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Flashing A-140 diode

itsmei

itsmei

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I am getting a A-140 diode and i want to know if you are able to pulse it. I am making my own driver and powering it at 2A. I want it to be able to pulse really quickly, just wondering if the diode will go to 2W as soon as you switch it on or does it gradually powers up to 2W?

Thanks
 





These diodes are pulsed in their original application so it should pose no problem. It is virtually instantaneous.

2A is pretty high. PLUS, the measured output and the amount of stress on the diode will be heavily influenced by how fast and wide the pulses are

I am NOT the electronic guy. However, in order to get more help from some of the better members here, you will have to provide info about frequency and width in addition to amperage.

Peace,
dave
 
I know that they can run at steady power at 2W but shorterns their life. If I pulse it, it will suvive longer, how many amps is 2w?
 
itsmei said:
I know that they can run at steady power at 2W but shorterns their life. If I pulse it, it will suvive longer, how many amps is 2w?
Click to expand...

VERY few are running at 2W. Plus, I think that you need to research pulsing laser diodes a bit more. ;)

Amps are not watts so I could not say how many amps, 2W is. There are way to many variables in your proposed equation to guess :thinking:

If you need 2W output (or higher), look into using more than one diode, utilizing beam combining optics and configurations. :eg:

Peace,
dave
 
I would actually *love* to know how to add a fast pulse into a DDL circuit.

I briefly investigated using a 555 timer, but once I realized that it could only handle 200mA, I got pulled down a rabbit hole of trying to figure out mosfets, and transistors, and all sorts of stuff that were way beyond me - and my head hurt. It IS possible to spend too much time in datasheets, especially when your chosen career path has nothing to do with electronics :(

I remember way back when I was a little kid and used to force my dad to take me to Active Surplus on Queen Street in Toronto - they had basic LEDs that would blink, no extra circuitry required. I wonder if there are basic diodes that will do the same thing? Or perhaps super simple 2 or 3 pin ICs that can handle lots of current, and blink at rapid rates.

My interest is not so much related to achieving a traditional pulsed laser driver, but rather to achieve a visible pulse for purely aesthetic purposes ;)
 
Laser diodes should have no problem being pulsed.
Using 2A would not give a overheating problem as long as the average power level is reasonable compared to the heatsinking.

The problem with 2A comes with something called optical breakdown, I am pretty sure it is independent of temperature and will kill the diode eventually whether it is pulsed or not.

As for building the controls, there are plenty of components that can handle the current, and the control circuit should be available in a basic electronic handbook.*

*Easy to say, Right.
It would take me some time and a better uplink to actually do it. :D
 
If there was a non smd IC that had 3 pins and a speed that was set via resistor value... I'd be in heaven!
 
you could always use an SCR circuit with a bistable multivibrator and a 555 trigger or some other type of clock pulse of your choosing. The SCR circuit should be able to handle your amperage. i use them all the time to create strobe lights that are powered by an ARC lamp so i'm almost 100% sure you'll be ok.
 
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Problem with an SCR is that you need to cross zero volts to turn it off (in a DC circuit, you hit it with a low energy pulse on the gate to turn on the conducting path, but the only to turn it off is to remove the supply power).

A simple timer circuit (astable multivibrator from the applications in the data sheet) produces enough signal to turn on a big power FET and it will turn off when the out sig returns to the opisite state of that used to turn on the FET. Most power FETs will handle more power than any LD you are going to user here and will easily switch at the rate you would want.

I'll try to attach a circuit I ripped from some other site that will give you an idea .
 

Attachments

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I may just run my laser at 1.5A to get me about 1.6W. I don't want to risk the diode getting destroyed, it is not worth the risk to me.

Thanks everyone for your advice!
 
Are you using a linear driver ?

If yes, just use a sink current driver and add the pulses to the current reference tree (closing it to GND for turn off the LD), and you have a linear with pulsed drive (AKA TTL modulation ;))
 
^ Dave, are you sure you're speaking about me ? (i was defined in a lot of ways, in my life, but usually "cute" was not one of them :p :D)

(oh, ok, maybe before 2 years of age :crackup:) :beer:
 
ITSMEI,
Don't give up. It's a good idea and not that complicated.
If you look at the diode's specs, you'll see that you can get higher power out by pulsing, but be ware that average of the power out does not exceed the devices maximum ratings (per manufacturer's recommendations, offer not available in all areas, shipping and handling and local taxes not included). You have some good suggestions and we would like to see your results. GOOD LEARNING EXPERIENCE.

Don't know daquin personally, but from his avatar, I don't know that I'd call him cute, maybe cuddley...
Peace, oh great one!
 
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