Micro-Drive laser driver by rkcstr

[GooeyGus]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

Any pics of the new drivers yet?

 

[V1.15]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

Ordered

 

[rkcstr]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

how much for a 95ma br driver? or adjustable 80-110ma   :
and shippping to australai

I have fixed output of 76, 87, 98, 100.  Adjustable driver for this range is ~27-150mA.

Or, for fixed output, if you can come up with some combination of 1 to 4 of the following values of resistors in parallel, I can do it:
8.2, 12.4, 25.5, 33, 75

Shipping to Aus will be $3 for economy (airmail), $12.50 for priority (6-10 days), or $25 for Express (EMS, <5 days)

And, no pics yet, I hope to get some tonight.

 

[rog8811]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

Now starts twiddling thumbs waiting for drivers to arrive :

Thanks for doing these drivers rckstr, I used some fixed ma ones to do some builds for another forum member and am mightily impressed by them.

But just a note to any new users....Do not solder the LD to the board before inserting LD into Aixiz housing as they are a b*gg*r to get off agin....not that I did that of course : (what was i thinking :-[)

Regards rog8811

 

[daguin]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

But just a note to any new users....Do not solder the LD to the board before inserting LD into Aixiz housing as they are a b*gg*r to get off agin....not that I did that of course : (what was i thinking :-[)

I would LOVE to have a picture of what your face looked like when you realized what you had done!

I'm sure that I had the same look on my face yesterday when it finally dawned on me (after much frustration) that the Sure modules that I am using to build my "predator sight" with are CASE POSITIVE!!! DOH!

Peace,
dave

 

[jake21]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

Ordered a few

 

[rkcstr]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

Now starts twiddling thumbs waiting for drivers to arrive :

Thanks for doing these drivers rckstr, I used some fixed ma ones to do some builds for another forum member and am mightily impressed by them.

But just a note to any new users....Do not solder the LD to the board before inserting LD into Aixiz housing as they are a b*gg*r to get off agin....not that I did that of course : (what was i thinking :-[)Regards rog8811

No problem  ;D

Also, there's a note [in the instructions] about soldering these to the diode after installing in a module/housing to avoid just that problem

 

[rog8811]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

Also, there's a note about soldering these to the diode after installing in a module/housing to avoid just that problem

....and I had read it
Of course the second time of soldering didn't look half as nice as the first time I did it.

Regards rog8811

 

[rkcstr]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

....and I had read it

Oh, ok, LOL. ;D

 

[john_lawson]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

dude these drivers are the bomb if you already know what ma you need
get these if unsure get the adjustable i think i ordered extra and didn't even need them lol

 

[rkcstr]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

Ugh... so for some reason etching the boards for this has been a real pain in the butt.  Plus, I realized that I placed a trace wrong on my test load AFTER I etched two batches  :'(

But, the test loads wiil work, it's just that the shunt resistor across the output for the "output cap discharge" was meant to have a bridged point that you could unsolder to disable it.  I wanted to be able to disable it because it will affect the measurement of the output across the onboard 1ohm resistor by about 2-3mA, which I guess isn't a big deal and won't make a difference if you're just using an ammeter instead.  Does anyone care?

Either way, I'm working on getting these ready to go, but looks like I may not have the first ones shipped until next week since the task of packing all of my tools and things I need to make these in my car and setting up shop at my parent's house isn't going to work.  And, I need to go home (which is about 250mi away) tomorrow thru Sunday, to help my mom out, so no way around it  :-/

But, I worked hard to get a couple done to show off, so here a pic of what they look like (test load on top, driver on bottom):

They don't look perfect (I was in a hurry ), but they work just fine. They should look nicer when you guys get them.

Actual measured range (on RED test load setting, with shunt resistor in place) was 27.7mA to 445mA.  The 2.7ohm series resistor is good for 463mA, so it just depends on the residual resistance of the pot at it's minimum setting, so there will be some slight variability in the ranges.

 

[daguin]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

Actual measured range (on RED test load setting, with shunt resistor in place) was 27.7mA to 445mA.

Unless this is a typo, these will cover the whole range for blues and reds, won't they? (except for those pushing the red envelope)

There are not many people beside myself thinking about how low the blu-rays can go.

Peace,
dave

 

[rkcstr]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

[quote author=rkcstr link=1206947255/264#266 date=1212035499]Actual measured range (on RED test load setting, with shunt resistor in place) was 27.7mA to 445mA.

Unless this is a typo, these will cover the whole range for blues and reds, won't they? (except for those pushing the red envelope)

There are not many people beside myself thinking about how low the blu-rays can go.

Peace,
dave
[/quote]

Yes, I was testing a full-range driver. For completeness, I just give the testing conditions as well, which I had the test load set to RED (if you look on the board, there's RED and BLU), which just corresponds to the amount of diodes it uses on the board (3 vs 6 for BLU). Set for RED, the output voltage will vary from about 2.5 to 2.8V over the full range of output current (BLU will be 4.2 to 5V over the low range).

The setting has no effect on the output current, though. It's only purpose is to allow someone to more accurately simulate a violet diode for the sake of testing say their batteries operating time or if their supply voltage will hold up, etc.

 

[drlava]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

Is that a single turn pot? how hard is it to set, at, say, 92mA?

 

[rkcstr]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

Is that a single turn pot? how hard is it to set, at, say, 92mA?

Yes, a single turn pot.  Adjusting is pretty simple for the lower end of any range, it just gets more difficult for the higher outputs since a smaller change in resistance is needed to change current compared to lower outputs.

For the low range (~30-150mA), setting to 92mA should be pretty simple if you just carefully adjust while watching the current.  I've be able to get currents set to within a mA or two on the high outputs like 400mA, so a lower output should be simpler

I have an Excel graph I made up to show the change in resistance and output over the range of turning the pot, but it's on my computer at home.  I can post it when I get home and you'll basically be able to visualize the "resolution" of the pot for adjusting output current in the different ranges.

Also, if you have some 1206-sized SMD resistors, you can modify the range to be very small  by simply putting your own values in for the two resistors on the board.   You just want your intended value to be relatively low on the range or in the middle if you want to be able to accurately set the current.

In the future I may buy other values of potentiometers to make the ranges more easy to adjust... the ones I use were intended to make the drivers simpler to assemble and less expensive for all ranges.

EDIT:  here's a quick Excel chart I made up to show what I said above:
http://rkcstr.googlepages.com/potoutput.xls

The graph doesn't show on google docs, but the calculations are still there on the far right. If you don't have Microsoft Excel, you can open it with http://docs.google.com/

 

[rubberband]

Re: Micro-Driver laser driver *NOW ADJUSTABLE*

hey i got the drivers today thanks for the fast shipping