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ArcticMyst Security by Avery

eBay Driver to avoid (imo)

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Dec 17, 2016
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I know the saying "you get what you pay for" but I'm a frugal slow learner. I bought a couple of these cheap eBay drivers with the intent of running 2 diodes off one at about 5 volts. The description was pretty vague, but they were cheap so I scooped them. Well, I led'd 2 of my good diodes double quick because the 1/2 turn pot goes from zero to god damnit in half a finger twitch. Also at 4 volts the driver got too hot to touch but running 2 of my cheap 5mw drivers at 5 volts and cranked all the way it ran cool and didn't cook even one of them by itself... 😠 I should have run a test load on it, but I doubt it would have helped much considering its odd behavior with the lesser diodes. Anyways, if I did something wrong or if these drivers are indeed crap I'll figure something out. Any ideas from the pros? Im seriously thinking about just getting a prefab 500mw or 1 watt unit in 808 for the engraver and buy a better driver for my red from a better source. I guess it also doesn't help much that I'm kinda n00bish to the electronics game. I do have basic knowledge from an extensive background in automotive and tinkering with various things but this micro stuff hurts my aging eyes.
 





diachi

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What diodes were you using? Series/parallel?

Your mistake was probably adjusting the current with the diodes hooked up and not a test load.
 
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I've seen warnings against adjusting the current while the laser diode is hooked up due to this kind of problem, but I've done it without a failure using drivers from DTR and Flamminpyro. I wouldn't want to try it with those cheap Chinese ones.
 
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I had my cheap 5mw diodes wired in parallel and I turned the power down pretty low before I hooked up my red. The part that has me baffled is the 5 mw diodes barely got warm at full power so I figured if I was careful with my adjustments it would be ok but it went from "on" to led in a bump. I'll grab some circuit board from radio shack today and cook up a more permanent power supply and test circuit. On the bright side I'm not out too much money with all this because I've been getting my diodes from burners from the thrift store for $3 a piece.

Edit: the diodes I was using were one flat package 3 pin 780nm and an open can 650nm both (I believe) came from a 16x Memorex lightscribe dvd burner and were (separately) happily roasting an old shoe @ ~12 feet away at 250ma on my lm317 driver. From the research I've done they can both handle more.
 
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