FREE DIY open source BOOST driver!!! Tested & working!!

[benmwv]

When I go to my mom's place for thanksgiving I'll grab my old laptop and see if it's on there. Hoping to have some free time to work on designs and stagnant projects over this break. Ive had a really high workload this semester so I've been pretty much out of the game recently. Also need to catch up with a lot of old friends though so I'm not sure how much time I'll have.

There's one thing I didn't notice before, looks like the fet is connected backwards. The way it is right now I think current would just flow through the body diode.

Aside from that, yes I think you've got the idea right. Hope this works out well cause you could make a very high power boost without using any dfn/qfn! Hell, it could be hand soldered.

 

[rhd]

When I go to my mom's place for thanksgiving I'll grab my old laptop and see if it's on there. Hoping to have some free time to work on designs and stagnant projects over this break. Ive had a really high workload this semester so I've been pretty much out of the game recently. Also need to catch up with a lot of old friends though so I'm not sure how much time I'll have.

There's one thing I didn't notice before, looks like the fet is connected backwards. The way it is right now I think current would just flow through the body diode.

Aside from that, yes I think you've got the idea right. Hope this works out well cause you could make a very high power boost without using any dfn/qfn! Hell, it could be hand soldered.

I thought it was backwards too, but then when you look at the datasheet page 7, the internal mosfet has the source pin going to ground.

 

[benmwv]

I think that's because the internal fet is N channel right?

 

[nellywhads]

Thanks man - never too late

Any suggestions on how much heatsinking I'd need at that current? Slash how I should go about heat sinking it?

I know that the mini has a heatsink pad but I'm not sure what exactly to put on it

Also @ nelly little late, but yeah you can make a nice and cheap laser if you pop an m140 and a mini drive set to like 1.25A in c6. You'll get long runtimes, reliable, and enough power to wow all your friends. Just make sure you get some laser safety glasses.

 

[benmwv]

http://laserpointerforums.com/f67/f...iver-tested-working-71433-73.html#post1104257

If you look there you will see a piece of copper I put beside the inductor in the first couple pictures. I used solder paste and reflowed it on like it was any other component. The piece of copper was cut from an old penny (I think the one before '82 were solid copper) and folded over. That small piece alone was enough to keep it running at 1.2 or whatever it was set to in that post continuously until the battery ran dead. I have also used short pieces cut off 1/8 inch copper bar.

Basically just put a small piece of copper on there in the reflow that is taller than the inductor and then use some thermal epoxy to connect it to the aluminum pill inside the host and that thing will never overheat. If you use a decent sized piece if copper that alone will be enough.

Also I'm not sure if you have laser goggles or not, but please don't let the prices scare you off. There are options that will protect you for cheap.
Uvex S1933X Skyper Safety Eyewear, Black Frame, SCT-Orange UV Extreme Anti-Fog Lens:Amazon:Home Improvement
These aren't certified for laser use but I've tested them with > 1W 445nm on my lpm and some others here have too. Nothing measurable was let through. They are only $8.

 

[nellywhads]

Score - I'll do just that

I have ordered up a pair of glasses but it's these ones here: New 200 540nm Eye Protection Goggles Green Blue Laser Safety Glasses Free Ship-in Safety Goggles from Home Improvement on Aliexpress.com | Alibaba Group

They actually arrived last week and my C6 host just arrived today - it's just building the drivers and putting it all together that's left now

There's no polarity on the M140's case is there? If there is, should I be worried about the benboost not being a constant negative driver? Or should the anodization of the C6 ensure that that isn't a problem?

 

[benmwv]

Case is floating on the diode, so it all works out well! And good to see you got glasses. Have you ever re flowed before? Be very careful not to put too much paste on the lm3410 pads!

 

[nellywhads]

I'm getting a solder paste guide made at my school Should be good on that end. Not sure where I can pick up cheap thermal epoxy though - everywhere I find Acrtic Alumina It's pretty much $15 cause of shipping to Canada

Any suggestions on what to do with a PHR-805T build for example? I'm parallelling this M140 build with a beoboost-phr build set to 119mA. The case on those 405's is negative though, and my host is also case negative

 

[mojoDodo]

Firstly,HUGE thanks to you guys for this. I always love small projects of this sort, and since I lack the knowledge to design something like this myself can't be more thrilled to have found this.

I was wondering, though, since I need 1.8A output to drive my blue diode is it better to set the board to 1.8A (assuming it can handle it), or should I parallel two of them like you said in your original post?