Laser diode drivers chips

[electrophile]

I'm trying to build a small laser cutter for making SMD stencils (among other things). Though I'm told that a 300mW laser should work fine here, I thought of experimenting with a 1W IR laser and I was hoping someone can suggest a suitable driver chip for this. Would something like this work? - **broken link removed** A lot of people use the LM317 but they are not very efficient. Are there any standard driver chips?

 

[betwixt]

I can't help with the required laser power although 300mW sounds rather weak to me. The driver IC should work fine though as long as the current is < 1A. Take care with the other components, that kind of switching regulator is fairly critical of the type of inductor and capacitors you use. If you folow the data sheet exactly it should work well and certainly be more efficient than a linear regulator.

Brian.

 

[electrophile]

Thanks Brian. Yeah 300mW does sound rather weak to me as well. Hence the 1W IR laser. Why does the current have to be less than 1A? Would I be able to drive **broken link removed** with this IC?

 

[betwixt]

1A is the maximum that the PAM2804 can regulate but provided you mount it on a sufficiently large (~1 x 1cm) copper area to help it keep cool it should be OK. Your biggest problem is the Ebay laser diode has no part number and only very basic specification so it's difficult to design a power source with confidence it will work as expected. That diode will get very hot so make sure you heat sink it well. Even 1W seems feeble for cutting anything, even SMD stencils, I know of companies that laser trim thin metal but they use water cooled lasers in the KW power region!

Brian.

 

[electrophile]

I intend to use this to cut stencils made from either Mylar or plastic transparency sheets. I first thought of getting a Silhouette Cameo for this but that does not seem to cut below 0.5mm pitch. Hence the laser. I think I need to do more research on this. Thanks again Brian.

 

[betwixt]

I tried an experiment. I ran a blue laser (ex blu ray disk drive) at 0.5W DC power so it produced an intense light. I did not use optics, it would take too long to set up. The native beam had approx 1mm diameter at 10mm distance so it was still a relatively concentrated spot. I could just feel heat from the spot on my finger after a few seconds. Obviously, it was the opposite end of the light spectrum from IR but it showed that far more power would be needed to do anything useful.

Brian.