HEAR! HEAR!

I second that.

Peace,
dave

Umm.. Thanks guys! I appreciate that!

I'm trying my best. But please understand, if i happen to be a little slow sometimes.
Between making the lasers, convincing lens manufacturers it'll be worth it for them to make four samples (instead of 30, like the first one), and answering emails, i sometimes even forget to eat, so... :

mm what's a q tip?

Q-tip---is the plastic stick with cotton on the ends, that is used to clear out earwax from ears.



brtaman

What brtaman said..


Otherwise, if you don't screw with the lens, it doesn't really matter. But i usually include a diffraction grating for a Liquid Sky effect, and it means removing the original lens, and then sometimes something gets in between..


So, while q-tips are not perfect for this purpose, it's the only thing available to everyone..
The best thing to do is not to get garbage in there at all of course! But that doesn't always work..

So if that fails, the next thing should be a small air-blower pump meant for blowing dust away - DX has these now - (but NOT canned air!!!!!!!!), and if that fails, it can be solved with dry q-tips, as long as you don't make it worse with "cleaning" fluids or impure solvents first.. You should NEVER touch the q-tip with your fingers, on the side that will be touching the diode window tho!

Usually blowing is enough, but again, it should not be done with your mouth. Otherwise you're spitting on it, even tho you don't see it.

My laser has arrived today,I was only able to play with it while was afternoon,it's starting to get dark here so I will be able to tell better what I think about it .The only strange thing is,I measured the current it's drawing from the battery,and it's drawing 180mA,isn't that too much?Or it takes more than 125mA from the battery but the driver only delivers 125mA to the diode?Because I have a red one that jayrob marked as 470mA and that's the exact current it's taking from the batteries.

the driver uses some current to do its work. jayrob must have measured from the batteries as well when labeling that, the diode is probably getting a little less.

Yeah, that's because Jayrob used a Linear driver - a 317.


A linear driver needs a certain amount of voltage more than the diode needs, but the current from the battery is ALWAYS the same as the current through the diode, right untill the battery voltage is too low, and the current starts dropping.


Since i like my lasers small, i make a boost driver for my blu rays, so they can work from a single 3.6V Li-Ion. A boost driver operates from a voltage lower, than what the diode needs, and boosts the voltage to the exact amount required for a certain current to flow through the battery, and then adjusts this voltage, to keep the current constant all the time.

So since the driver has to put out 125mA at 5.4V, this means it is putting out 5.4 x 0.125 = 0.675W of power (P = U x I)..
The battery has ~4V when full, and if the driver was only pulling 125mA at 4V, the input power would be 0.5W..

It's not a perpetuum mobile - it can't make power out of nothing.
If it has to boost the voltage, that means it needs more current, than it will put out.


So what happens is, it pulls a higher current at a lower voltage, and converts it into a lower current at a higher voltage..

Also, as the battery slowly discharges, and the voltage drops, it has to pull more and more current. So on an empty battery, the current draw from the battery will go close to 300mA. The lower the voltage, the more current it needs, to put out the same power.


That's why you're measuring a higher current. Power OUT can not be higher than power IN. In fact, it can't even be the same, due to the losses (>84% efficiency = <16% losses). So power IN actually has to be higher, than power OUT.

But 180mA is not that much! It means your battery must be very full. Did you charge them first, or did you just use them? My experimental units draw like 360mA from the battery, but that's because the output current is 170mA..

The difference between the current in and current out with linear drivers is only a couple of mA. Not 55mA..

In fact, with linear drivers it doesn't really matter at which point you measure the current. It's pretty much the same all the way, as there is only one way through the driver.

So there, you can just as safelly (or more, cos you don't have to disconnect the load) set the current through the load, by measuring the current from the battery.


Boost drivers convert the relationship of power going in, and the power coming out, and at a high efficiency - the power out is not that much lower, than the power going in.

With a linear driver, you have to give it the current the load needs, but at a higher voltage.

For example, a red at 333mA with a 317:
The diode will be getting 333mA at around 3V = 1W of power coming out of the driver. (0.333A x 3V = 1W)
The driver will need more than 6V to operate. Two Li-Ions are in the optimal range, so it will get 8.4V when batteries full. 0.333A x 8.4V = 2.7972W going INTO the driver with the batteries full!

This means, the efficiency of a 317 with full Li-Ions is only 35.7%! 64.3% gets converted to heat by the driver, because it has to give the load the same current it is drawing, but at a much lower voltage. As the batteries slowly discharge to 6V, the efficiency slowly climbs to 50%. 50% is still getting converted to heat in the driver.

The average efficiency is ~43%, which means, that only 43% of all the battery capacity ever gets used. The rest is lost as heat.


A good boost driver on the other hand, hardly ever warms up. That's because it doesn't discard excess power, but converts the power into what the load needs. There are some losses in certain components on the driver, and they slightly warm up, but the components never go above 40°C, or feel hot (measured with an IR non contact thermometer).

The efficiency is a pretty constant 84-86%, so the batteries get used to their fullest. Only 14-16% is lost as heat.


Otherwise, i am very flattered, that you people believe, i can make a perpetuum mobile. I wish i could. But i can't..



GamerBR:

Yes. It has to, as the 3.6V battery doesn't have enough voltage for a blu ray diode which needs almost 6V.. The current through the diode is ALWAYS 125mA, be it on a full or completelly empty battery.


Oh, and one important thing. PLEASE don't use the diffraction grating for a few days! Don't take the original lens out! Many people get garbage on the diode window, when they do so, and then make it worse by "cleaning" attempts.

Please make sure you read the cleaning instructions, and otherwise, make sure they are never needed.


Also, PLEASE do NOT atttempt to open the module that is in the head without special instructions! There is an IMPORTANT step to do FIRST!
I can show you pictures of what it looks like, if you're interested. It's much safer than taking it appart.

You have the gift to make a small question become a huge answer,but not making the answer boring .About the diffraction grating I must be doing something wrong when putting it,is there any special way to put it on the laser?I'm just removing the original lens and puting in place,I must also use the spring when putting it,right?All I'm getting with the diffraction grating is a huge thin line.

Hehehe, that's what you're supposed to get.. ;D
You need smoke or fog to make the effect visible.

A scanner would "wave" the beam left and right, and also draw a line on a wall. Here a lens draws a line, but in both cases you need smoke or fog. You just need to focus it into the thinnest line on the furthest wall first.


And there i was hoping you would listen, and NOT use it just yet...
Please don't get garbage between the lens and the diode. Please?

And if you do get garbage in there, please don't "clean" it.

Well, i wanted to explain why the current from the battery is different from the current through the diode in this case..

There is no easy way to explain it completelly, other than to explain it completelly...
Someone else may be wondering about the same thing, and hopefully, they will now understand it..



Otherwise, how do you like your laser?

P.S. I ended up keeping the host where the battery is tight for myself.. You can use protected batteries in the host you got. It would prevent them from overdischarging, as i have tested my driver, and it just keeps on working down to 2.2V, and a Li-Ion discharged so low will get damaged quickly.

I really liked it,the color is very unique,it's difficult to focus your eyes on the dot,even more at a distance,which makes focusing to infinity weird,at close range too,but to infinity is worse,it never seens to be really focused :P.About the build quality I have nothing to add,the reviews already talked about that,it's just perfect,the only thing is that my host(which I knew before arriving)is a tight fit for protected cells,I have to remove it from the top,but I have no problem with that.The lens cap glows much more than I imagined,you can really use it as a flashlight if needed,and it spreads the light all over the place.Oh and now I also have protected cells,it arrived before the laser :P

Between,I think dogs can see 405nm better than we do,I put it near him outside during day and with a big dot,I could almost not see it but he just got crazy chasing it(yes I know it's dangerous for dogs,that's why I used with a really big dot,so there is no problem if I hit him on the eye,although I'm still careful about not doing it).

Again.. I never actually remembered to tell you, but i did NOT give you the SAIK host, which is tight for protected batteries. I gave you the same host as i gave everyone else - Rominsen - i kept the tight one for myself, as i don't care about that..


Which protected batteries did you buy? The gray ones? Those are thicker. The blue TrustFire fit in the hosts i shipped out very well. I didn't send anyone the tight host, as i managed to convince DX only to ship me the other model, which they sell under the same name..

For what I remember you said that you bought Rominsens and received mostly SAIKs,and that the Rominsen was actually the one that was tight for protected batteries,and as I at first chose ultrafires and you didn't got it(or got some other instead,or it was even tighter for batteries,I don't remember),and the ones that chose Rominsen got SAIK because of the battery problem the only one that was left was the Rominsen that you would get to yourself,but I asked to get that one,did I miss something?I think that was all.I bought the blue protected ones,it not really tight,probably if I give a shake they would come out,but there is not reason to risk damaging anything because I'm just lazy to remove the top,from now I will just have to open the top instead of the cap to take out the battery :P

Check your emails. Wow, it's 90 of them.. Ok, look at the picture i sent you back then.. I'm attaching it here..

You were expecting to get the tight one, and i never told you that i managed to send you the good one. So i understand, that you still believe you got the tight one, but you didn't - i sent you the same one as everyone else who ordered the modular model.


It was the other way around. Rominsen is not even officially available on DX.. Only SAIK is sold. I ordered SAIK, but they shipped me a mixture of the two.

I received 5 Rominsens and 1 SAIK. The Rominsens were spoken for which is why i first thought i would have to send you the SAIK, but then someone changed the model request, and i was able to give you the Rominsen, like everyone else.


I kept the tight SAIK for myself like originally intended. Blue TrustFires are stil not that bad in the SAIK, but they are perfectly smooth in the Rominsens.

Don't know why yours would be tight, if i can get them in my SAIK.. It's the gray ones, that don't go in the SAIK. All my blue ones worked perfectly in all the Rominsens tho.


But i don't think you need to unscrew the head to get the battery out. Even with the SAIK, i just have to hold the laser in my hand, and tap on the other hand, and the battery comes out enough for me to pull it out. This won't damage the laser, you don't have to worry about it. Just don't bang it against the table.



Otherwise, these host almost drove me crazy. I had to rely on a model, that is officially not even sold there, and on one person always remembering to send me the right one.. *:


But is anyone else with the Rominsen host having a battery, that is tight?



Anyway, the picture shows why i only recommend getting the blue protected TrustFire batteries, and not the UltraFires. The UltraFires are thicker, but the TrustFires work in all of them.

I confused the story them :P.The only part that it's a bit tight it's on the PCB and the work to unscrew the top is the same of unscrewing the tail cap,so it's not a real issue.

Oh, so you take the top off, and the spring pushes it out? I guess that would work too..

But this DX stuff can get annoying man! Maybe the batteries have too big tolerances..
Looks like i will have to make a stock of them, and always include battery pairs that i test myself from now on....

Oh, and sometimes, you can force the wrapping into shape, and then it works smoothly. You should try forming it a little.. Cos i think only the wrapping could be a problem.

Try this:
- Put just the top 10mm of the battery in the tube, and tilt it around in a circle with a small amount of force
- Turn the battery around and put just the bottom 10mm of the battery in the tube, and repeat.

I think that would bring it in shape. Are both of them tight? I still don't understand it, as i'm holding this battery and host in my hands now, and there is like 1mm of room in the tube, next to the battery, if i push it to one side. *:-?



Anyway, how did the undisguising go? Did you tighten it back in fully? Ain't it pretty? I need to make me a new personal blu ray..

I'm sorry to tell I was the third .I couldn't find any tweezers to try to tight the module,but I think it's already in line with the edge,at least 30AWG wire is not passing(0.25mm).I will recheck it later when I'm able to find tweezers.
I might try that later,but I don't really think it's necessary,as I said,I just have no problem taking the battery from the top
EDIT:I just checked now and the other battery from the pair comes out nicely from the tailcap,the other one that is a anomaly :P

No one follows instructions these days.. *;D

But i'm glad to hear the other battery is ok! I was starting to get worried, that they changed the battery model now! *: *They changed everything else already.. * >

I think you were so convinced you'd receive a tight one, that you made it true.. *;D



Otherwise, if you just pulled the lens cap out from the top, it can't really be tight, as the rim of the lens cap was between the edge of the head and the heatsink. So you should tighten it a little.

Anything you can stick into the notches (in the aluminum of the module) should allow you to turn it. It's just, that the tweezers are the easiest, as you can then grab from both sides at once, and turn with more power.
Again: The notches are in the aluminum, NOT in the battery contact board. Don't poke the contact board..


If you tighten it fully, the heatsinking will be much better.

Oh I thought tweezers were needed because there was something locking the module in place,it's just screwed,I used a small flat screwdriver to tight as much as I could,it must be ok now.
And hey,thanks for the CR2s,now my DX laser is working better,not that I will use it much now with a 318mW red laser,200mW green laser and your laser :P.I adjusted the pot and the current is now at 325mA

Yes, the entire module, when closed, is just one piece of aluminum, with threads on the outside, which allow it to screw directly into the head.
If it's not loose, it's good. It just shouldn't rattle around. If you tighten the body fully into the head, the heat transfer will work, like it's supposed to. Then you don't have to worry about the duty cycle. It can be left on as long as you like.


Well, i hope you can still put the 3.6V CR2s to some use occasionally. At least your dilda now works like it's supposed to..
These chinese wanna-be drivers are really annoying sometimes.

I put up some underwater laser pictures on village idiot's review thread: http://www.laserpointerforums.com/fo...=1216101466/20

Igor, thanks again for everything, I am very happy with the laser!

Glad to hear that!


So.... Only the fishing lures were underwater, right?



P.S. I had some ideas for waterproofing your laser.. Need to try them out first.. One of them would require some insulation tape every time, but it would be easy to put on and take off. The other one would be a plastic tube with a glass lens on top, a button on the bottom, and the laser in the middle. No idea about the depths it could take tho..

That sounds really cool Igor, I'll send you an email about it when I get back from my trip. Unfortunately it looks like my waterproof diving bags have vanished, so I am going to try to make soem kind of makeshift diving bag (a plastic water bottle lol). Hopefully it will work, but don't worry I am not putting your laser in there, a green one instead.