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Direct driving a 445nm

sopark4000

sopark4000

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Ok I have a variable power supply (adjustable voltage and current) and I wanted to know something, if I am running an a140 diode in an Aixz module with heat sinking etc what voltages and current will result in what output power.

Basically what voltage and current should I use on an a140 diode when trying to get outputs between 600-1,300mW. All help is appreciated. :thanks:
 
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lazeerer

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Re: Direct driving a 445nm LD

I Use 4.5v on my supply.

Lets say you have an Average efficient diode. Running the diode at 1.2A should give you a Range from 1W-1.3W...

If you have a Low efficient diode at 1.2A you will be ~800mW-1W.

If you have High Efficient diode at 1.2A you will get ~1.3W-1.45W.
 
Isoleucine

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Re: Direct driving a 445nm LD

I assure you that we have power graphs for the A140 on LPF. However, diodes that Lazeerer appear somewhat rarely, I want to say 10% but I am not sure as I do not own many lasers and/or LPMs.
 
lazeerer

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Re: Direct driving a 445nm LD

Isoleucine said:
I assure you that we have power graphs for the A140 on LPF. However, diodes that Lazeerer appear somewhat rarely, I want to say 10% but I am not sure as I do not own many lasers and/or LPMs.
Click to expand...

My Numbers under average and Low efficient do not appear rarely.

They are the Most common ones that you get when buying a 445nm diode.

My Numbers for High efficient diode are some what rare. There is Usually ~6 in each projector. But it verys so You might get 10 in one and 2 in another.

So I would not call my number all rare and say 10% of all diodes.

Ive tested quit a few 445nm diodes and for the Average 445nm diode i have writen are pretty accurate.
 
sopark4000

sopark4000

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Re: Direct driving a 445nm LD

Yea luckily I have a LPM so I'm probably going to start at 4.5V and 1A and see what kind of output power I get and then I'll go from there. I'm probably going to keep it around 800mW so I get a good lifespan out of this setup and if I want I can easily turn it up to 1.3W
 
Benm

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They're about that efficient really, but you have to subtract the treshold current of roughly 200 mA, so you'd need about 1200 mA to get to 1 watt outpout.

You can use a lab supply if its good quality, but make sure you stay in current regulated mode!
 
sopark4000

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Yea my power supply has variable voltage and current. I have a LPM so I'm probably going to start around 4-4.5 volts at 1A. I want to run this set up around 800mW output in an attempt to get a better lifetime out of the diode. I know every diode is different but there must be a power graph for the A140 somewhere. I tried searching but couldn't find it. Anybody know where it is?
 
ARG

ARG

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Benm said:
They're about that efficient really, but you have to subtract the treshold current of roughly 200 mA, so you'd need about 1200 mA to get to 1 watt outpout.

You can use a lab supply if its good quality, but make sure you stay in current regulated mode!
Click to expand...

It really depends on the lens used, and the heat of the diode ect.
 
jcswimmer305

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Assuming a good driver-diode system, the efficiency from the current the driver outputs to the light that you get is going to be about 25-30%...

So if you can adjust the system to be about 1.2Amps with variable voltage...(times the .25-.30 efficiency factor)... I think for about 900-1000mW you should have about 3Volts of power.. (Watt = Volt x Amp x %Efficiency)

(PLEASE CORRECT ME IF I'M WRONG)


What I would like to know is How can you tell whether a certain system takes a specific voltage or not? Like for those lasers WITHOUT variable systems? I know if you go over the given voltage limit, the excess current is going to be driven out as excess heat in the driver, which will ultimately fry your driver and your diode eventually. If I'm doing a build (40-50mW), how can I find the appropriate Voltage for my driver)??
 
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Flaminpyro

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Here is a couple readings I have taken from different 445 diodes.
These are from the cream of the crop 1 to 1 efficiency or better :D
this is raw output from the LD no lens.

700ma input @ 5.71 volts = 743mW out
700ma input @ 5.11 volts = 762mW out
700ma input @ 5.74 volts = 772mW out
700ma input @ 5.11 volts = 772mW out
700ma input @ 5.10 volts = 778mW out
700ma input @ 5.13 volts = 786mW out
700ma input @ 5.10 volts = 789mW out
700ma input @ 5.11 volts = 790mW out
700ma input @ 4.35 volts = 791mW out
700ma input @ 5.66 volts = 802mW out
700ma input @ 5.03 volts = 813mW out
700ma input @ 5.14 volts = 823mW out
700ma input @ 5.11 volts = 826mW out

these are actuate readings I have taken, hope this helps ;)
 
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