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ArcticMyst Security by Avery

Powering laser diode from aa battery?!!!

Joined
Sep 3, 2013
Messages
166
Points
18
I bought a 1.5w laser diode and the people send me a datasheet with a video of them burning stuff, And i noticed there running the diode on 4 1.5v aa batteries!

I thought you're not meant to do that or do the batteries have like a maximum output current?

Can i do the same with my diode or do i have to use a driver, and i'm just wondering if it does damages the laser diode powering directly from battery do you think they just done it to make the laser look smaller i mean they did have over 300 of them so doesn't matter if they damage one right?

 





Joined
Feb 23, 2012
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1,282
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It's generally a bad idea to use 4x AA batteries to power a diode.

I'm assuming it's a blue 445nm diode, right? They generally have forward voltages of 4.5-5.5V, and using 4x AA batteries may or may not kill it.

The voltage may sag enough that the current drops down to a reasonable level, but it's best to use a driver to effectively control the current.

Ask them if they give refunds if you blow the diode by following their video. :D
 
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Joined
Sep 3, 2013
Messages
166
Points
18
The diode in the video is a 1.5w 808nm i guess they just used batteries to make it look smaller and easier to setup.
I don't want to take a chance so i will just use a driver.
 
Joined
Sep 12, 2007
Messages
9,399
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They were using a driver in the video. AAs can supply over 8A, so 6V worth directly into the diode would have killed it nearly instantly.
 
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Joined
May 14, 2013
Messages
9
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1
I bought a 1.5w laser diode and the people send me a datasheet with a video of them burning stuff, And i noticed there running the diode on 4 1.5v aa batteries!

I thought you're not meant to do that or do the batteries have like a maximum output current?

Can i do the same with my diode or do i have to use a driver, and i'm just wondering if it does damages the laser diode powering directly from battery do you think they just done it to make the laser look smaller i mean they did have over 300 of them so doesn't matter if they damage one right?

Rest assured, there is a driver module in that housing. You can't power a diode directly from 4 AA batteries. Well, I should not say you can't, you can but it would only last for a second before lights out!
 
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Things

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Joined
May 1, 2007
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Shorting AA's through a DMM, I've seen peaks of over 15A from a fresh battery. Sometimes you can get away with running a diode off batteries with a single resistor, but you need to calculate it carefully as the current isn't constant in regards to voltage. Voltage goes up, so does current. It's also inefficient and will get very hot.
 




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