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ArcticMyst Security by Avery

Will this LED driver do for an LPC-826?

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May 7, 2013
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Hello, I am building a red LPC-826 and have planned to run the diode off of this one driver. These diodes are meant to be powered no more than 500mA ±50, but I was told that drivers such as these could be used too? My plans are to run off of 2x 16340 (7.4v) to prevent early shut, instead of 1x 18650 (3.7). But the input voltage of the 17mm circular driver is stated to be 1.5v, is this power way to much that could be dissipated to heat loss? How about those special "circuit protected" boards for under volt supply? Thanks.
 





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Sep 12, 2007
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That driver could work. You should first put a test load on it and check how well it is regulated over your intended input voltage range.

What is "early shut"?

Stick to the input voltage rating. 7.4V will almost certainly pop something.
 

Fiddy

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not sure if you can use any of them drivers for the LPC-826 because its case negative, meaning the case of the diode is connected to the metal of the host, only way to get around that is to isolate the the diode from the case.
 
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Thanks for the input. So what specific drivers could I use for the LPC-826 aside from isolating it? By 'early shut down', I meant that when the voltage of the battery drops below 3 volts give or take the whole system shuts even though there is 80% of juice left, some posts described how by using 2x 16340 batteries solved the problem by splitting the load evenly, running the laser for longer periods.
 

Fiddy

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find a driver that can run with case negative diodes and you will be set.
 
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Thanks. I see that it comes down to the driver being continuous or not in order to decide to isolate the case diode or not :)
 
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Jan 29, 2012
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Try a Moh linear they are cheap, continuous negative and have the input current options you need.;) (Mohgasm.com)
 
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Yea Moh drivers are great, they offer everything one needs, but I'm on a super short budget and opening my possibilities of ordering this (sometimes included in flashlights) driver. With this, I can modify the resistor to output around 500mA ±50 and of course isolating the diode by using anodized heatsinks.

edit: Quick question. Shopping for resistors and along with their resistance they have Power rating. Is this the tolerance of the resistor or how much it needs to resist?
 
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Joined
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Add up the price of ordering a few resistors + shipping (unless you already have them ;)) to the price of the board and you'll probably be at the price of a Moh linear! They are some of the cheapest laser diode drivers around...;) Anyway good luck! :beer:
 
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Jul 22, 2012
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If you want you can easily build your own driver with a LM2941 or LM317. You can see at my build (HERE) it is possible to get them rather small. They are also VERY cheap to build.
 
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