Current Optimizing the 532nm Newwish

[Helios]

We know everything about 445nm, LOCs, LCCs, 6X BR, 12X BR so lets figure out the even more popular 5mW Newwish 532nm :yh:

We all know "Pot Modding" is generally a bad idea. I remember trying it back when green pens first started showing up on ebay (early on in the life of this forum I believe) and after frying it instantly that was the last time I messed with the pot on a 532nm pen. However its reasonable to assume that the people assembling these pointers are not doing it carefully or with any great accuracy so adjustment could be useful.

What I would like to do is get several members including myself to donate some 532nm newwish pens to a member who has the ability to test several things including.


Driver current range
Diode current vs IR output graph (test to death on one or a few)
Diode current vs 532nm output graph (again test to the death for a few to determine crystal maximums)
Tests to compare driver/diode functioning using a single li-ion vs 2 AAA cells

Hopefully with this data we could figure out an ideal current for maximum 532nm output for the average newwish pointer with decent run life. This way instead of saying "dont pot mod!" we could say "optimize by using a test load to set the driver to XXXmA".

Obviously there are many variables that come into play between one pointer and another but I would think that an average best has to be better than blind pot turning (pot modding). If this works and people start to try it we could assemble graphs like those found for bluray and 445nm diodes that give information like diode life, set current, measured output etc.


So if anyone else likes my idea we need some more contributors and a member willing and able to run them through the ringer. Please post if you are willing to donate and/or if you have a suggestion of who could conduct the best testing.


Newwish Pen Donations

Helios - 3

 

[Wolfman29]

But are all NewWish pens created equal, as in their drivers are the same? I have never had a NewWish pen, so I don't know.

 

[rhd]

This is a brilliant idea, but I see one stumbling block.

What IS a NewWish pen?

I don't mean that to sound obtuse, but I think the term has come to refer to a general style of pen laser, as opposed to a single particular model. If we're going to try to test different aspects of a laser (to death in some cases), then we really need to know that we're not running 5 different tests, on 5 completely different lasers.

To be honest, I think pot-modding DOES work (anticipating a brick through my window any moment now). Yes yes, hiss, booo, snarf.... I get it.

It makes sense to discourage pot modding. The people who generally ask about it are trying to burn stuff with a $7 pointer investment and a screwdriver. They typically have zero understanding about the fundamentals of laser technology, and are infinitely more likely to wreck their laser than they are to achieve power gains.

BUT, the concept of increasing current to a DPSS module, is probably a fairly sound one at this stage. These cheap DPSS modules are probably getting under 15% efficiency (IR mW to 532mW). Well, for a truly 5mW 532nm green, that would still imply under 40mW of IR. The reality is that 808nm IR diodes at 300mW and under are all essentially minuscule in cost. If a 40mW 808nm IR does exist, it's probably more expensive than a 150mW 808nm IR, simply because of the low demand volumes. In other words, I'm suggesting that they're probably using IR diodes that are capable of pumping higher than needed to achieve 5mW of 532nm output. The crystals, etc, can probably also handle doing more than 5mW output.

I'm not suggesting that we'll see 5mW to 100mW increases, but to consistently quadruple a 5mW output shouldn't be a stretch.

A while back I was using some DX 50mW 532nm modules in builds where I needed to replace the stock drivers with DDLs. Here's a scenario where you wouldn't expect much *wiggle room* because DX actually sells higher powered identical modules (100mW, etc). I found in testing that there was actually a remarkable bit of leeway to DIY my own driver at almost 2x the current those diodes were being fed, without any apparent pain from the module. The DPSS output didn't linearly double with the current, but it had a substantial increase (from memory).

 

[Helios]

This is a brilliant idea, but I see one stumbling block.

What IS a NewWish pen?

I don't mean that to sound obtuse, but I think the term has come to refer to a general style of pen laser, as opposed to a single particular model. If we're going to try to test different aspects of a laser (to death in some cases), then we really need to know that we're not running 5 different tests, on 5 completely different lasers.

I have ordered dozens upon dozens of black barrel newwish pens off ebay direct from Hong Kong over the last few years and they were all identical. That was what I was considering to test. Now will there be variations within this style of laser and between similar models? Probably but will the diodes usually be the same? I would think most likely. So even if the drivers are different as long as the current is set the same it shouldnt make a difference. Also if we do find variations we could always run separate tests for separate models and post them accordingly. Maybe we will find one model that is ideal and yields better results...

I would suggest including pictures of the internals though so that members can compare their own components so they know if they are working with known or untested units.

I remember reading somewhere that the crystal sets should all be the same as they are mass produced to one set of parameters for these pens (I could be wrong on this). I know alignment and quality will vary but that is just an obstacle I think we will have to live with.



EDIT: These are the models I am referring to

http://cgi.ebay.com/5mW-532nm-Green...ultDomain_0&hash=item2c5bd24beb#ht_3420wt_952

 

[Helios]

I thought there would be more interest in this.

 

[qumefox]

I've probably ripped apart a dozen of these. from pretty much the same seller (IQS I believe) and i've seen at least 5 different drivers. Same goes with the 405nm pens. Like most cheap chinese products. What parts they're made from varies week to week depending on who's selling the parts the cheapest.

Though there's a certain driver i've found in one of the 405nm pens i've dismantled that i've been trying to track down the source of, since it'd be perfect for another project i'm working on. It was a boost converter that from what I can tell by the information I can dig up on the controller IC, can do up to 500mA and up to 6V.

 

[rhd]

I think the level of interest is a reflection of economics.

Sure, we might gain the ability to reliably get 30 or 40 mW from a $6 pointer, and that would imply 6x or 8x over spec.

But we could also just BUY 30 or 40mW for $9.

I think the potential gain just isn't significant enough to attract attention. In fact, I think the process of trying to get just 0.5x over on higher power pointers might be more compelling?

 

[Helios]

I think the level of interest is a reflection of economics.

Sure, we might gain the ability to reliably get 30 or 40 mW from a $6 pointer, and that would imply 6x or 8x over spec.

But we could also just BUY 30 or 40mW for $9.

I think the potential gain just isn't significant enough to attract attention. In fact, I think the process of trying to get just 0.5x over on higher power pointers might be more compelling?

It seems like it would be a great project for beginners though. What better way to learn about test loads, diodes, batteries even DPSS systems than to tinker with optimizing a laser that if destroyed only costs $6. 50mW of 532nm doesnt get my blood boiling either (I just paid for my 300mW in your GB today) but it might be fun for new enthusiasts or even simply lead to a better forum wide understanding of DPSS systems. Maybe what we find here can be used with high power units. Maybe we can take some model of underspec 100mW and turn them into 150mW using the same sort of technique and testing. These are all hypotheticals because very few people mess with DPSS because no one has any data evidencing advantages of doing so.

I think DPSS needs to be brought into the realm of the DIY hobby and what better way to start than using the worlds most inexpensive DPSS units.