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Cell phone charger to power m140???

BillClinton1

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I'd like to hear the in's and out's of using a 5 volt cell phone charger to power a m140 or similar diode. Has anyone done this? I've got probably a hundred chargers.. could be a hundred lasers soon?
 



Anthony P

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I think a cell phone charger may be a bit low in voltage and amperage to power the driver required to power m140. That being said, I frequently use cell phone adapters for low power diodes/drivers without any problems. For higher current diodes/drivers I often use inexpensive regulated wall adapters of appropriate ratings without any issues.
 

paul1598419

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What Tony said is true, but your choice of an LM317 as a linear driver is also not a good choice. These can be driven at 1.8 amps to get better than 2 watts out, but not with that driver. A switching driver would be a better choice.
 

BillClinton1

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I understand the lm317 is a less than ideal/intelligent choice, but it's what I had on hand. Although I try to make everything myself sometimes I should just buy online.... That said, I wasn't wondering about powering a driver, I was wondering about direct driving a m140 from a cell charger. I have numerous chargers that are listed at 5vdc and 1500 mA output, seems like it's ideal for the m140, but I could be wrong, given the changes that take place with temperature and whatnot. Anyone tried this, ever?
 

paul1598419

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No, you should never drive a laser diode using a power supply. These are current devices that need to be driven as such, otherwise they will draw more and more current as they heat up leading to an ultimate failure. The one thing that could save you is the limited current of the power supply, but I wouldn't try it unless you are willing to lose the diode in the process.
 

Encap

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What Paul said above ^^^.
Not a good idea to directly drive a laser diode.
 

BillClinton1

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Thank you Mr Paul for your wisdom. I'm trying to keep everything as diy as possible, and I've looked and looked online, but nobody will tell me how to drive an m140, except just flat out throwing money at somebody who's gonna do it for me. I really want to build a driver myself. Is there a driver I can build, or do I just have to throw in the diy towel and send somebody money?
 

paul1598419

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Building a buck, boost or SEPIC driver from scratch is a daunting task as any constant current switch driver is. You would be much better off buying one of these drivers over trying to build one. Most people who actually build a good working one actually build many and sell them it is that work intensive.
 

Anthony P

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Good drivers. Good company.
 




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