OPEN SOURCE: "CC-Boost" - 2.4 Amp boost driver - RC1

[vortish]

guys does any one have a working one set for 500ma that i could buy say for ten us.. I was sent a pp gift card by a old army budy so no actual money from the donation thread would be used. All the ones I find on flea bay are to big or not the right ma I do not want to use a led driver for this ld I got from a old blue ray 12x drive. I put up a add on craigslist and got three drives and one happened to be a 12 x blue ray.. amazing what people will give a way for free... I should have a few more drives showing up soon. I have a old friend that works for a company in ohio that all the old pcs still had drives and he said all were dvd rw 16x drives so I should have ten to twenty 650 didoes when they get here. but I need a driver for the 12x blue ray and I think 350 to 500 ma would be about right

 

[rhd]

well, bother. I reflowed another, doing it slightly different as to not overheat the IC- which worked, the IC was barely warm when I was done. However, same story- only output 1.78A@~5.2V, and got extremely hot. Even with the inductor heatsinked, the IC got so hot I burnt myself (again- i should stop doing that, eh?). Not sure what the deal is. Since I have the parts I will probably just make the rest, but then be done with these- maybe I just have bad luck. Or, maybe the IC's are knockoffs- I am not sure where/what seller Rifter (who I bought them from) got them from. I think I will try benboosts next, at least I know 100% certain those work
Not trying to imply these don't work, they obviously do- I am just obviously not having any luck with them.

You never did tell us (specifically) what the input power to your drivers was coming from. Can you give us some details?

 

[crazyspaz]

You never did tell us (specifically) what the input power to your drivers was coming from. Can you give us some details?

A panny 18650. And yes, they are fully charged I tried a variety of batteries, all fully charged, all had the same result.

 

[rhd]

A panny 18650. And yes, they are fully charged I tried a variety of batteries, all fully charged, all had the same result.

Can you send one of the completed boards that has this problem to me? Maybe I can spot the problem and fix it.

 

[The Lightning Stalker]

You never did tell us (specifically) what the input power to your drivers was coming from. Can you give us some details?

I was powering mine from 2 and 3 paralleled
18650s.

guys does any one have a working one set for 500ma that i could buy say for ten us.. I was sent a pp gift card by a old army budy so no actual money from the donation thread would be used. All the ones I find on flea bay are to big or not the right ma I do not want to use a led driver for this ld I got from a old blue ray 12x drive. I put up a add on craigslist and got three drives and one happened to be a 12 x blue ray.. amazing what people will give a way for free... I should have a few more drives showing up soon. I have a old friend that works for a company in ohio that all the old pcs still had drives and he said all were dvd rw 16x drives so I should have ten to twenty 650 didoes when they get here. but I need a driver for the 12x blue ray and I think 350 to 500 ma would be about right

Wow nice score! I think 500mA can be done
using a single 150mΩ sense resistor and an
800Ω Rset + Rtrim, but these boards aren't
exactly tiny. Have they even been tested
at 500mA? You would be better off going
with a Micro Boost.

 

[crazyspaz]

Can you send one of the completed boards that has this problem to me? Maybe I can spot the problem and fix it.

If you want to shoot me your address I will send one out to you. I have double checked, all the components are where they should be, theres no shorts, solder pads are filled- only thing I can think is I got a bum part.

 

[The Lightning Stalker]

Try turning the pot all the way to the left or
right and not moving it while the thing is on.
It's a longshot, but that would simulate a
single resistor with the lowest possible gain.

 

[vortish]

Lighting the problem with micro boost is they are about twenty bucks and that far more than I can spend right now. I may try to do a lm317 driver I know they are good to about a 1amp but that is far more than what i am looking for. This is not going in a regular hand held host but some thing I going to make out of some of the materials I have here at home! As for why because I have no hosts that could be used to make a 200 to 400 mw laser out of. So I going to work on a portable lab style host. I have 18650s batt holders that I got from Keystone electronics as a sample. They will send to designers, students of technology, and engineers for free you can get up to four samples from them. I have ordered from them a couple times for small things like alligator clips, batt holders from AAA to 18650s, they have project enclosures to. I have a really nice on my desk that I want to turn in to a small projector. any way I like this thread a lot and look forward to seeing what come out of RHD's great mind

 

[crazyspaz]

Try turning the pot all the way to the left or
right and not moving it while the thing is on.
It's a longshot, but that would simulate a
single resistor with the lowest possible gain.

This 2nd driver I put together maxes out at something around 1800mA. Then it heats up, and current output drops. This is without touching the pot

 

[The Lightning Stalker]

Okay. Then more must be going on here
besides just the pot. If the pot doesn't
move then all it does is act as a fixed
resistance. Unless moving it while it's
running causes a permanent failure inside
the 6298. It's either that or someone is
selling us fake or defective chips.

 

[rhd]

Okay. Then more must be going on here
besides just the pot. If the pot doesn't
move then all it does is act as a fixed
resistance. Unless moving it while it's
running causes a permanent failure inside
the 6298. It's either that or someone is
selling us fake or defective chips.

I doubt that. It's not the kind of IC I would expect to see faked.

Address sent. When I receive the driver, I'll see if I can figure out why it didn't work.

 

[crazyspaz]

Just put another together, and this time the inductor basically caught on fire. Coincidentally so did my thumb.

This whole, "burning myself on a boiling hot driver" thing is getting a little old -_-

 

[IWIRE]

Here is one I built using a soldering iron. It's putting out 2.3a @ 5.2v. It had been doing so for about a minute or two while I was trying to get my camera to focus. As you can see, it never did quite focus.

The input is 4.1a @ 4v. It's not heat sinked at all it's just sitting on an OSH stencils solder paste spreader. It got fairly warm but far from smoking hot. I have three builds I did for friends running this drive so far no one has said they quit. I know one gets used fairly often. The other two probably collect dust in a drawer.

Guess I better send rhd another donation, I just built another drive I'll wait till after the weekend, I'm hoping to use my new toaster oven this weekend.
Edit: Usually when I adjust current on a drive I kill the power to it, adjust, then power back on and check. Repeat until I get it set. Don't ask me why I do that. I have no idea.
Since we are trying to figure out what is going wrong, I adjusted this one with it powered on through it's range. It was a nice normal smooth increase and decrease in current, nothing weird happened. I have no idea whats going on with them. Wish I could be of more help but I'm not smart enough about this stuff.

 

[crazyspaz]

I wish I would have thrown an inductor in for RHD- I wonder if thats my problem for some reason. Especially since one, ya know....caught on fire...I ordered them from mouser, so who knows. I will get some from digikey and try them.

 

[djQUAN]

Caught on fire? For that to happen with a boost topology, it looks like your IC may be shorted between pins internally or due to solder bridged between pads.

 

[rhd]

I wish I would have thrown an inductor in for RHD- I wonder if thats my problem for some reason. Especially since one, ya know....caught on fire...I ordered them from mouser, so who knows. I will get some from digikey and try them.

No worries, I'm hoping the problem will be apparent when I look at the driver. I've got a lot of inductors sitting around though if I need them.

I may do some reflowing tonight.