What current should I run my diode at?

I recently bought an A140 diode off Daguin, and there is so much confusing information that I don't know what current I should run the diode at.

I want the diode to last a total of at least 200 hours, I was thinking of using a 30-60 second on time with a 50% duty cycle (30-60 seconds off).

This is the host I am using: DealExtreme: $11.99 Cree XR-E LED Flashlight Complete DIY Body Shell/Casing Kit with Driver Pill (2*CR123A/1*18650)
I will make my own copper heat sink.

Any help will be greatly appreciated

AAlasers

If you read through the forums here it'll give you an indication of how well these diodes operate. The A140 works happily at 1A. I've run them continuously @ 1.3 amps for 3 days.

I was thinking of running max current with the microboost (1A), so hearing that the diode runs smoothly at this current, Ill probably shoot for that. What life time could I expect with 30 second @ 50% duty cycle running at 1.5A.
Thanks for replying

AAlasers

These are run at around 1.8A pulsed (80% duty cycle) max in the projector.

Which means, 1.4A is a good current on the high side.

1.5A might be pushing it, I'd do 1.4A.

Thanks for replying, I just have one more question, with the the Micro flex drive or the Microboost, how do I get the 4-4.3V output voltage that I need to run the A140 at such high currents?
Will a standard 18650 work (L-ion)?

AAlasers

AAlasers said:

Thanks for replying, I just have one more question, with the the Micro flex drive or the Microboost, how do I get the 4-4.3V output voltage that I need to run the A140 at such high currents?
Will a standard 18650 work (L-ion)?

AAlasers

Click to expand...

A single 18650 is great. Use the flexdrive not microboost. Microboost only has a max of 1 - 1.2A while the flex can do 1.5A.

Another reason why 1.4A is good, goes a little easy on the flex drive, staying just below its max.

AAlasers;

The small host you have chosen will not provide a lot of heatsinking.

Make sure your copper heatsink is as large as possible (>2oz.).

Remember that in the projector, these diodes are in a large heatsink,
cooled by a lot of airflow.

Use a hi-capacity name-brand #18650 battery.

LarryDFW

Thanks for replying everyone!
I went ahead and got the microboost with a preset current of 1000ma. I got this before I read the last two most recent replies. I should've waited longer and bought the microflex:banghead: , but the microboost will have to make do. Will it have overheating issues being driven at 1A, will it lose efficiency? I probably wouldn't be able to safely drive my diode over 1A anyways, as my heatsink will most likely be insufficient.

Thanks for any replies

AAlasers

Microboost has a lower efficiency than the flexdrive. It should be ok at 1A heat wise. Ask drlava to be sure though.

Tabish said:

These are run at around 1.8A pulsed (80% duty cycle) max in the projector.

Click to expand...

What does it mean "80% duty cycle" when we are talking about pulsed driver? 4minutes ON 1 minutes OFF?

Tabish said:

Which means, 1.4A is a good current on the high side.

1.5A might be pushing it, I'd do 1.4A.

Click to expand...

You are doing 1.4A pulsed, right?

How much will be safe in case will be used CW current driver (LM317 based)?

Regards,
Alx

No, he means 1.4A continuous. The Micro Boost can do ~1.5A I believe (Late, I know).
These diodes are incredibly resilient.

alx said:

What does it mean "80% duty cycle" when we are talking about pulsed driver? 4minutes ON 1 minutes OFF?

Click to expand...

He's talking about what goes on inside the A140 projector that Casio makes. Their power circuit pulses at 1.8A, at probably a high frequency duty cycle (kiloherz or higher), which allows them to regulate the power. Because it has a duty cycle, it the diode isn't receiving 1.8A all the time, but only as a ratio of the pulse's repeated "on" and "off" time.

You are doing 1.4A pulsed, right?

Click to expand...

No, he's talking about continuous. It's lower than the 1.8A Casio uses, but that's because it is continuous, and not pulsed.

How much will be safe in case will be used CW current driver (LM317 based)?

Click to expand...

Ultimately it will depend on how well you can heatsink your diode.

The LM317 itself will go up to 1.5A I believe. Look it up in the datasheet for the precise figure. Remember that the LM317 also dissipates quite a bit of heat too, so you'll need to heatsink your LM317. Make sure your resistors/potentiometers can handle that much current (and power) as well.

Finally, it'll be a pain to adjust the current using an LM317 circuit. You might want to consider a Microboost or Flex drive. There are modifications for the microboost to go to 1.4A. It's in one of the posts on the forum (I can't remember which).

Bionic-Badger said:

No, he's talking about continuous. It's lower than the 1.8A Casio uses, but that's because it is continuous, and not pulsed.

Ultimately it will depend on how well you can heatsink your diode.

Click to expand...

I know about LM317 limitations regarding higher currents (we are operating with fractions of Ohm). So we can say that 600mA continuous, will be super safe current for these diodes with a moderated heatsink (small one attached supplementary to AIXIZ nut) and will output over or around 500mw with 405g1 lens. Right?

Bionic-Badger said:

Finally, it'll be a pain to adjust the current using an LM317 circuit. You might want to consider a Microboost or Flex drive. There are modifications for the microboost to go to 1.4A. It's in one of the posts on the forum (I can't remember which).

Click to expand...

Which one you are considering better for 445nm diodes: FlexDrive V5 or MicroBoost? Which one is selling it now?

I know that in the past, on top of BST section has been all interesting links regarding drivers and sellers. Now these links has been removed! So become confused. Can you help me a little please?

alx said:

Which one you are considering better for 445nm diodes: FlexDrive V5 or MicroBoost? Which one is selling it now?

I know that in the past, on top of BST section has been all interesting links regarding drivers and sellers. Now these links has been removed! So become confused. Can you help me a little please?

Click to expand...

Either the flex or the boost will work in your set-up. The discussion about 1.3A vs. 1.5A and/or "efficiency" is interesting, but will not make a "visually observable" difference. Both will power the laser. Both will be hella bright. Both will burn stuff. The flexdrive is out of stock anyway right now.

With the variability from diode-to-diode, you cannot really look for a specific output anyway when operating at the limit of the driver. Some will put out 1W with the driver all the way up. Others will put out 800mW with that same driver.

If you are looking to "tweak the last available mW" out of your diode then this discussion has value.

If you want a bright, burning, blue laser, don't worry about it. Use the boost that you have, at the 1A setting it is on. It will be a VERY nice laser and will last longer.

Peace,
dave