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soft start lab driver + TTL for 445nm

Seoul_lasers

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I am curious if anyone knows of a good quality soft start driver for these new 445nm diodes.
Any recommendations?
 



charliebruce

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Yoou could custom-build a DDL based driver if size isn't a problem. Why do you need soft-start? How long do you need it to take when starting up?
 

Meatball

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Put about 3F of capacitance across the diode. That's good for a soft start and soft stop. It will be a 1-2 second delay, but its really nothing more than a cool affect.
 

Flaminpyro

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Soft start should not be neede do you know these diodes are pulsed at 700ma so being that they are regulary turned on and off rapidly why do you think you need soft start ?
 

Seoul_lasers

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Ok, then I guess these will be fine for instant on. I just have had some nasty blowouts due to instant 100% on some 405nm diodes. That's my concern.
 
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Flexdrives have a current ramp up when turned on :p
It used to be a noticeable delay but in the newer revisions the ramp up happens faster.
Unless he took it out these days? I dunno. Haven't had one in a while :p
 
Last edited:

BlueMeanie445

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This may be a good idea, I remember reading something about these diodes being warmed up. IIRC there is a point in the projectors startup that the diode is held at threshold current for a few seconds.

I think I saw this on PL, but the threads are gone for now.
 

Meatball

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I don't believe so. The flexmod is linear, not switching. So a ramp up feature would be much more difficult to achieve with such a small size. It is also modulation controlled. That's a good clue that says it is more of an "instant" on/off.
 




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