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Rominsen L-D030   >150mW mod






Re: Rominsen L-D030   >150mW mod

IgorT said:
Hey, wannaburn, did you have much trouble centering the expander?

Isn't that part the most "fun"? ;) Almost more than aligning the crystals. The last time i had to break the glue three times, because i couldn't get the expander perfectly centered before the glue would set, and the tiniest fraction of a milimeter off center shoots the beam out at a crazy angle...



Did you use all special optics for this build? What power did you get out?
Click to expand...


I put the glasses on and very carefully line it up, put a pin drop of Cyanoacrylate to tack it and epoxy when done. The optics are the original DX parts, and the output is just over 100mW. Its the same driver as my 200mW build but running at 3.6v opposed to 4.5.
 
I'm kinda scared of CA, because of the nasty vapors it produces. They can completely ruin optics or even the crystals.
And epoxy is so messy. :(


Is the "driver" from a DX pen laser? Why do you use those? They don't do anything more than a resistor and a capacitor would.. Hardly any of them are current regulated. And those that are, are usually not regulated well.

I'm gonna use the CNI driver here, because it's a great driver so i don't want it to go to waste and don't have much time at the moment, but for the next build, i'm gonna make a driver from two AMC7135s, and a resistor in parallel, to waste 50mA, and get 650mA through the diode.


If you want, i can send you the PCB drawing, once i prepare it. It will have place for up to 4 AMCs in parallel, as well as for several resistors in parallel, and some caps for the diode. It will be the size of the usual DX pen laser "driver" wanna-be, with the optional button in the middle.
 
I got my This laser but is anyone having problems with the push button>?

anyone know how to get the module out?
 
Re: Rominsen L-D030   >150mW mod

IgorT said:
I'm kinda scared of CA, because of the nasty vapors it produces. They can completely ruin optics or even the crystals.
And epoxy is so messy. :(


Is the "driver" from a DX pen laser? Why do you use those? They don't do anything more than a resistor and a capacitor would.. Hardly any of them are current regulated. And those that are, are usually not regulated well.

I'm gonna use the CNI driver here, because it's a great driver so i don't want it to go to waste and don't have much time at the moment, but for the next build, i'm gonna make a driver from two AMC7135s, and a resistor in parallel, to waste 50mA, and get 650mA through the diode.


If you want, i can send you the PCB drawing, once i prepare it. It will have place for up to 4 AMCs in parallel, as well as for several resistors in parallel, and some caps for the diode. It will be the size of the usual DX pen laser "driver" wanna-be, with the optional button in the middle.
Click to expand...

If your very careful and place a small low speed fan beside your work, the fumes are no longer an issue. When I use it, it is just a temp hold, and very, very little ammount. The driver is the 7135 which gives 1400ma seen here---  http://www.laserpointerforums.com/forums/YaBB.pl?num=1210699419 (the pic is the 750ma, but same idea ;))
 
Oh come on, toked, i posted pictures and explained it.

You unscrew the head, and then you see what you can see in the pictures on the previous page. Then there is a ring (also shown in the pictures), that you can unscrew, by sticking tweezers into the two tiny holes.

After you unscrew the ring, you can pull the module out. But i have to warn you, once you get it out, the problems with the pushbutton could get worse, because you can not fix them from above anyway.. The only way to fix the pushbutton problem is with the module mounted in the body. You have to support the driver PCB just enough.
From above, the tube is thinner than from below, so you can not add anything to the driver with the module out of the laser and then stick it back in, or if you do, it won't help, as the driver will then be in the wider part of the barrel.


What exactly is the problem you are having? MY pushbutton was fine untill i took it appart. when i put it back together, it wasn't like before anymore, and it would take a lot of time to mount the module in the same exact position, because of the spring, and because it rotates as you tighten the ring. Do what you can from below with long tweezers.
 
Igort the problem with the button is that when i push down, the laser will flicker very low power or shut off, but if i press it hard its fine.
 
Ok, that is happening because off bad PCB support. There is only a piece of foam there.

Do not take the module out. Use long tweezers to pull the foam out, and then fold a small piece of paper and stick it in, under the PCB, with tweezers.

Test the button and repeat if necessary, untill you get it just right. You can't solve this problem by taking the module out, but you can make it worse. If there should actually be an electrical or even an alignment problem by now, that is a different issue. I hope it's not, but due to the stupid build, pressure on the button can misalign the diode or even rip it's legs off or cause a bad solder joint to open up. The harder you push the button, the worse it gets. The PCB really needs to be firmly supported.

If you put too much in, the button will be pushed constantly. You need to experiment, to get it just right.
 
Well, i RMA'd my Rominsen, and because the return shipping is more than half of the price, they instead offered me another one for $10. I took it, and i hope i get a more powerful one this time. They accepted a photo of my LPM measurement with a description of the mode hoping as proof the laser is bad.

In the meanwhile, i took the crystals and the expander off the diode and measured it, and this diode is putting out more than 200mW at 270mA. Maybe i could use this diode in combination with the crystals from one of my dead KD50s, if i can find a good alignment..


I also managed to shape a thin alluminum heatsink, to stick in the tiny gap between the Rominsen body and the DX200 module, along with some thermal paste.. Looking good so far!
 
Hey, Wannaburn, did you ever manage to get more than 10-15% efficiency by hand alignment?

These cheap chinese lasers can have 30-35% efficiency, in some rare cases even more, but as soon as i remove the crystals, and try to put them (or some other crystals) back on, the max power i can get is 10%, 15% if i'm very lucky.


The manufacturer must have some fancy 7 axis, 5 dimensional micro precision alignment tools or something.
 
Re: Rominsen L-D030   >150mW mod

The most I can hit is 25%, it seems to be the norm. I do it all buy firing the laser at its lowest possible power and set the position. From there I turn up the power and see what happens. The one thing im finding is, that method works up to 1 watt but becomes problematic when the crystals heat up. Its a touch and go thing for me and a bit of luck of course ;)
 
25% is actualy not bad at all. I would love to get 25%. Do you pulse it, when you do this? What minimum power do you set the diodes to?

I mount the module in a vice for heatsinking, and then i play with the crystals. Unfortunately the ones i was toying with now, have the expander glued on top, so i couldn't align the fast axis of the diode with the diagonal of the crystal by looking through it. Need to break the expander off. I got the best results this way in the past...
 
Ok, so i had half an hour of time, and decided to try the CNI driver with the DX200 module. First of all, i must say the CNI driver is absolutelly AMAZING!

It can keep a constant current through the diode with only 0.39V on top of what the load needs! And it's adjustable with a pot. I've never seen anything like it.


Anyway, i mounted the mode hopping (the first i took appart) DX200 module in a vice for heatsinking, and i would get only 120mW at 690mA.. Increasing the current to 730mA didn't help much, but actually made it drop in power faster. Lower current would make it average higher as expected. It would still drop to 100mW quite fast (with more current it would drop below 100mW)...

So i decided i would save the Rominsen body for the other one, and to do the KDX200 project first (DX200 guts into KD50 body). I thought the massive body would be good for heatsinking. I had no idea how fast the entire head would get hot! Maybe there is no heat transfer from the module to the body in the original pen housing, since it doesn't get this warm, and the walls are thin there.

Still, the laser would only produce 80-90mW. It is not much brighter than my KD50 at 65mW.


I am cooling it down at the moment, to see if it has any effect, then i'm lowering the current even further. Unfortunatelly, it is impossible to measure the current in the original laser without influencing it, since it is completelly unregulated. The most i measured with a 3.6V Li-Ion was 730mA once, so i dare not go higher than that. But since the DMM lowers the current even in the 20A range, it could actualy be higher.


Strange things i noticed along the way:
- It get's hotter in the KD50 body, than in the pen. No idea about the actual module temperature in the pen tho.
- I think it starts mode hopping faster than it did. Maybe the current should be lower, maybe higher, but not likely.
- If i screw the module into the KD50 head very hard (with the threaded ring) the laser would stop working. At first i thought it was an electrical problem, but it still consumes 690mA, just no green.
- With better cooling and constant current the power is lower than in the pen body.

Some of these things (lower power, faster mode hopping, the laser turning off in some cases) make me think i slightly displaced the diode by a fraction of a micrometer or something.

Need to do more testing after cooling down.



I will be more careful with the next one. That one would seem to only have an electrical problem - it turns of from the driver bending down. Must be a cold solder joint (i hope.. if i'm unlucky, it's a dislodged diode again). If i support the driver it works and puts out >130mW for a while. I will also record the power at every step to see if it suddenly drops at a certain point.

I should also try to estimate the original power consumption (while still in original body) by hooking it up to the PSU and adjusting the current till i get more or less the same power as with the batteries.


The 0.5W C-mount diode in my CNI only uses 650mA, so i would be surprised if this used more, but who knows. It could be heavily overdriven, especially when people use Lithiums.
 
hey Igort, did you mess with the pot at all on the Romisen 30mw? if so any good output thats worth messing with the pot?
 
I don't "mess" with pots. If i do anything, i carefully adjust them while limiting the max current on my PSU in case i overshoot. And all this while measuring through a DMM (because my PSU is not as exact - i should recallibrate it).

You should measure your current FIRST! I got 250mA on the primary CR123 and 270mA on the 3.6V Li-Ion. The small difference makes me think the circuit is somewhat regulated, but not perfectly.


The pot does adjust the current, but a small turn can cause a big change.

At 300mA, the diode itself puts out slightly more than 200mW of IR. At 270mA it is more like 160mW. Due to the bad crystals i could not get any improovement out of it. The power is usually 15mW dropping to 7 fast, with a higher current is was slightly less than 16mW dropping faster.


If you do anything, you have to do it while measuring the current between the battery and the driver, and making VERY careful small adjustments, and not go above 300mA. It might help or it might not. Most likely you won't even notice the difference without an LPM. A much higher current might kill the diode. I have no idea what it is actually capable of.
 
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