Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

How to Register on LPF | LPF Donations

ROUND 2 SOLD OUT!! - CHEAP 445nm (true-blue) diodes group buy

Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

So, guys, when are we going to have safe specs like current, voltage etc? In less than a month?

Also, these can be used in handheld builds right?
 





Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

Silvershot said:
So, guys, when are we going to have safe specs like current, voltage etc? In less than a month?

Also, these can be used in handheld builds right?
Click to expand...


Rated for a minimum of 4V and a maximum of 6V at operating current ... that's for the 1W LD, but the voltage should be the same.
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

While doing the output power test before harvesting.... LD voltages
and current and pin ID could also be taken.... IMO


Jerry
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

lasersbee said:
While doing the output power test before harvesting.... LD voltages
and current and pin ID could also be taken.... IMO


Jerry
Click to expand...
I second this.

Pontiacg5 said:
Are these diodes floating ground like a bluray? I hope so...
Click to expand...
They are groups connected in series so I believe they are.
 
Last edited by a moderator:
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

I'll do my best to find out as much as I can about these diodes including power output while installed in the projector..
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

ScopeGuy20 -- I see you paid for one here. Should I remove your name from the round 1 list?

Peace,
dave
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

I think the one he bought here was actually for someone else.. not 100%$ sure tho.
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

Quote:
Originally Posted by lasersbee
Since they can come from 2 different projectors (XJ-A130 2000 Lumens)
and XJ-A140 2500 Lumens).. they may perhaps be 2 different LDs...
So maybe something like.... 445A13 (2000) and 445A14 (2500)...
and if they are the same LD... just XJ-445...
Just my $0.02...
Jerry

Quote:
Originally Posted by diachi
Yeah that makes much more sense.
Also, I agree with your other post. Whatever the power in the projector is, we can drive harder than that - that's assuming they are actually under driven to produce a life span of 20,000 hours.



IMHO (my .01--I don't know enough to offer .02)--It would not make much sense to make a different diode for both the 2000 AND the 2500-- wouldn't they just push the 2500 a tad more.
And at 20,000 hrs these surely are being underdriven--thus the reason for 24 of them. Does not look like the biggest heatsink and no duty/rest cycle in a projector.


if you have not seen these...


http://www.aboutprojectors.com/pdf/c...140-manual.pdf

CASIO
and...


CASIO
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

hakzaw1 said:
IMHO (my .01--I don't know enough to offer .02)--It would not make much sense to make a different diode for both the 2000 AND the 2500-- wouldn't they just push the 2500 a tad more.
And at 20,000 hrs these surely are being underdriven--thus the reason for 24 of them. Does not look like the biggest heatsink and no duty/rest cycle in a projector.
Click to expand...

It could very well be not a difference of diode manufacturing, but a difference in binning. Just like with computer processors: they make them all the same, then test them and bin them according to the clock speed they achieve. Faster ones are more expensive, slower ones cheaper. They do the same thing with LEDs, and the same thing with laser diodes. They make all the diodes, and lower-performing ones get binned into the part number for the cheaper projector, higher-performing diodes get binned into the part number for the more expensive projector.

As manufacturing improves, they can even start new bins at higher levels. Or it could very well be that a few diodes outperform even the highest bin, but there aren't enough of them to warrant fully separating them out into their own part number, because so few come out to such a high performance. Hence the "freaks" some people get here.
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

lasersbee said:
Since they can come from 2 different projectors (XJ-A130 2000 Lumens)
and XJ-A140 2500 Lumens).. they may perhaps be 2 different LDs...

So maybe something like.... 445A13 (2000) and 445A14 (2500)...
and if they are the same LD... just XJ-445...

Just my $0.02...

Jerry
Click to expand...

Agreed...

Maybe add the zero:

445 - A130
445 - A140
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

Here's my idea of comparing the diodes between the two models.

1. measure the light output of the stock module. I don't which way is better, using a light-meter or testing each diode with a lpm.

2. measure the voltage drop of each diode while running in the stock module and calculate an average voltage. Also measure the current going through each string of 6 diodes and calculate an average current.

If the average current and voltage are higher on the 2500 lumen version, then the diodes are likely to be overdriven.

If the average voltage and current are the same in both versions, then the 2500 lumen version has better, more efficient diodes.
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

Not neccesarily overdriven ... just driven harder.

Also, it will be hard to get current readings as the diodes are attached by ribbon cables which aren't easy to solder onto or get electrical contact with ... Voltage across each LD should be fine though.
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

diachi said:
Not neccesarily overdriven ... just driven harder.
Click to expand...
Of course, but you get the idea - you don't get more power for more money.

diachi said:
Not neccesarily overdriven ... just driven harder.

Also, it will be hard to get current readings as the diodes are attached by ribbon cables which aren't easy to solder onto or get electrical contact with ... Voltage across each LD should be fine though.
Click to expand...
Not as easy, no, but at least it's only 4 times it needs to be done per unit.
 
Last edited by a moderator:
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

We really need to know safe current (20 00hrs), I know it's tricky to solder on flat cables but it can be done.

You need to desolder flat cable from one diode, and solder wires in place where diode pins were soldered.
And then solder diode and 1ohm resistor in series.
Then you can do measurements and be sure that nothing can go wrong.

It's not that difficult :)
 
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

Hey EF, maybe I missed this or it has not been replied yet. When will the diodes be shipped to us?
 
Last edited:
Re: ROUND 2 SOLD!! Awaiting payment - CHEAP 445nm diodes group buy

As soon as he gets the projector and some time to remove everything safely.
 
You must log in or register to reply here.


Back
Top