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ArcticMyst Security by Avery

Building 5mw driver for blue diode - help

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Apr 4, 2015
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We made the circuit here http://www.learningaboutelectronics.com/Articles/Laser-diode-circuit.php for the 5mw circuit and tested it working with a LED
We tried using this diode http://o-like-ui.kancart.com/item_detail/148#!detail but can't get it powered - the specs don't show a minimum power requirement. Is this really true?
We're trying to downgrade it for our purposes at 10-20mw.
Mobile right now - I'll update links when I'm at a computer later.
 





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Sep 12, 2007
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That Author is an idiot. Using the LM317 in that way outputs constant voltage at 2.8V. That might work for some red diodes, but it will either not work at all or just blow up any other laser diodes. Your blue diode should be undamaged, however.

The link to your cart will not show up for anyone besides yourself. We can help you better if you link to the product itself.

Google LM317 constant current, and you'll find a circuit that works.
 
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Apr 4, 2015
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Thanks. Bread boarded one LM317 cc circuit, and the power output was weird - we're calling it a night and will come back at it tomorrow after some more forum input.

That link should work - I'm not logged in and have used it to copy over specs to a friends' phone. (Have one with specs and another with circuit, ha)
 

diachi

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Thanks. Bread boarded one LM317 cc circuit, and the power output was weird - we're calling it a night and will come back at it tomorrow after some more forum input.

That link should work - I'm not logged in and have used it to copy over specs to a friends' phone. (Have one with specs and another with circuit, ha)


What do you mean by "the power output was weird"?
 
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We adjusted one for 5v (per the diodes 'regular' voltage spec on the website), but only getting a couple hundred mA. We're having to use several resistors since we're still playing with it, so we think we just stayed up too late on it and missed something, ha.
We'll do some more boarding tonight.
 
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You do not adjust the voltage with a constant-current driver. You adjust the current. The voltage will depend on the load. Be sure to power the circuit with 9-12V.
 




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