EVER KILLED A DIODE?? see this..

[GBD]

most all the Pros use these in thier PJs
They must be stupid like me --uh?

I never insulted you nor called you stupid, I was just pointing out another cheaper approach of protection.

If I where to adhere to your argument though, the fact that I use TVS diodes must make me stupid, makes computer designers stupid, makes motor drive manufactueres stupid, make automotive engineers stupid make (insert billion other electronic related material here)... and so on so forth.

I can tell you right now that a crowd analogie is not very effective here, as Im not just suggesting some random piece of equipment with a psuedoscientific approach, Im going by what is an industry common, and has been proven to work in applications that far more demanding then laser projectors, and some which definatly require just as much if not more protection and design.

But if you pay 50 to100$ for a diode
$8 seem little to protect it

While in that logic it would make sence (like RHD pointed out earlier with the projector analogie), I still ask, why bother spending more then you have to? Im sure you could put the extra money towards bettering your projector elsewhere or whatever you wish to do. Granted its your money and you are to use it as you see fit, but that doesn't excuse the fact that others should know of the alternative rather then let one company monopolize a device at whatever price they wish to pull out of thier ass. Hence competition and consumer choice.

a lasorb and laserbug would not fit in pen or most handheld host lasers.
I think mainly lab builders will want these. I like the ability to swapout a diode without a soldering iron. makes testing WAY easier to.

The info at the Lasorb site about ESD is informative just disregard the sales pitch there. I suspect not all got 100 on the quiz//maybe?

Thats another reason why I like TVS, I can literly solder the thing onto the diode's pins. plenty of room there. While true, some parts of thier site is informative about ESD, however it is (obviously) baised towards thier product, Ive yet to see a store that promotes the products of others above its own. most of those stores don't stay in bussiness very long. So I'll agree with you there, sift out the baised content and you might learn something if you are completly new to the concept of ESD however a part of research is to aquire information from multiple sources, then logically formulate your own conclusions.

At the end of the day, you have to realize that Im not here to shit on your thread with baseless acusations and pseudoscience. I just demand to know why as a consumer why aren't more cost effective and practical alternatives aren't openly accepted and discussed, rather then get slammed down while pangolin flexes thier laser muscles for everyone to see.

Sounds alot like Lasercommunity and their horse blinds set only on wicked products. Id hate to see the forum come to that.

Cheers.

 

[hakzaw1]

I just went back and reread my OP.

I inadvertanly posted a different link from the one had wanted to post.

I didnt know til just now that I had linked the order and price page.

If you will please see the link I meant to share you may cut me a little slack.

If nobody read any of the other stuff there I would have not cared.

I honestly did not post it to sell my 10 lasorbs. I did not know it even existed until last nite.


I learned some new things reading that link but sadly not enough to fully understand your post GBD- but I never claimed to be a wiz ..Im not the dullest knife in the electronics drawer but for sure not the sharpest. So I agree with all you said..hopefully some day I will understand it.

 

[rhd]

I don't know why, but I'm just super-skeptical that there is anything in a Lasorb that is a non-standard component. When you read their website, it sounds like they're phrasing things (especially descriptions about their product) to direct you away from any specific knowledge of what's inside.

I'm sure they work - but I'm also sure that they don't contain anything that couldn't be sourced from Mouser/Digikey for one-tenth of the price.

 

[Bionic-Badger]

Yeah, that site seems very strong on marketing, and weak on benevolent info. The quiz is not very useful, especially as the situations seem very contrived. Who is going to attach a long copper braid to the inputs of a laser diode except only in the most temporary of circumstances? The different ESD protection approaches are a little more useful, but are generally simplistic or assume that someone will not do some more research into appropriate ESD protection--especially considering the cost of a LASORB.

I think LASORBs are probably just a variant of this ESD protection circuit Sandia National Laboratories investigated for preventing ESD from accidentally triggering laser-diode ignition systems:

http://prod.sandia.gov/techlib/access-control.cgi/2003/032100.pdf

It provides protection against even severe human body generated ESD (25kV, 120A peak), the same kind of EDS the LASORB company purports to prevent. It combines a TVS as well as RC circuits and transistor gating to prevent transients shorter than 7.5us from arriving at the diode. The document is a more useful diode protection document because it goes over what exactly goes into protecting a device against ESD, such as gating current for durations longer than ESD lasts (1-2us or so), while still being useful for active switching. Even the operation of the protection circuit sounds a lot like the LASORB's operational description.

The next time I place an order I'll get some of those parts and do some tests. PHR-803Ts are so cheap these days that we can use those for the test diode since 405nm diodes are pretty sensitive.

 

[hakzaw1]

I appreciate all the comments here. I can see a big need for DIY ESD protection. I, however, completely lack the skills and time to go that route. Pangolin seems to be a very savvy company promotion-wise. They apparently sell a lot of Lasorbs. No doubt they have the largest share of the lasershow software market. I have met Bill Brenner twice and he is a hard guy to not like. I truly wish when growing up I had gotten into Heathkits and learned more about electronics instead of building go-carts from lawnmower motors. Cant go back and change that. shoulda..coulda...woulda.

 

[BShanahan14rulz]

it's better now, since kits are cheaper. I remember when I was a kid I picked out a little blinky LED kit out of a catalog. $30 for two alternating red LEDs.

About 2 years ago I bought a variable pulse rate stroboscope, including flashtube and pot and project enclosure, for $15.

I say go for it. It is a good stress reliever too

back on topic, this is how it is with everything. You can go out and learn it yourself, or just buy a product that does what it needs to for a bit more money. I see nothing wrong with the business.

What I do see is a lacking of information about what exactly we should be using to protect our diodes. Everybody says use a capacitor, but I doubt that a lasorb is just a capacitor. Never seen people say "Oh, just throw a TVS and rectifier on that sucka'."

I'm glad to hear that TVS are used widely for esd protection, perhaps they are harvestable components from other devices? Or are there too many different variants with too many different parameters?

 

[GBD]

What I do see is a lacking of information about what exactly we should be using to protect our diodes. Everybody says use a capacitor, but I doubt that a lasorb is just a capacitor. Never seen people say "Oh, just throw a TVS and rectifier on that sucka'."

I'm glad to hear that TVS are used widely for esd protection, perhaps they are harvestable components from other devices? Or are there too many different variants with too many different parameters?

TVS are widely used in the industry indeed, but the varaince in parts and application is definatly huge, like I said earlier, Ive seen them used from computers to industrial VFDs that drive 800 horse motors. The sheer range of application makes it a bit unsuitable as a part to extract from a specific product.

That is more or less like asking what appliances you should gut to get a specific valued resistor or a capacitor from. This makes it cheaper and easier to simply order the part with your exact design specs in mind rather then to try and harvest it. This can't be said about everything though, like our beloved Crapio diodes, but I think we can already call those parts application specific.

Regarding the anti-parralel rectifier in addition to the TVS, I think it might be even better to employ Schottky diodes instead of rectifier diodes. Main reason comes to my mind is the responce time can be increased, noting that rectifier diodes have a recovery time to worry about if they are subjected to repetative transients. schottky diodes on the other hand, have no recovery time at all, there is nothing to recover from in the first place from the nature of the diode, should yield a switching time well below and faster then rectifier diodes (<500pS for those smaller diodes, a few nS for the higher power ones). Aside from that rapid responce, these diodes have an even lower forward voltage then thier rectifier counterpart, which is even nicer.
So it makes me think that a TVS/schottky would be an even more potent mix then just a rectifier diode.

Or, you can have an active controlled version of the above which employs the circuit mentioned in bionic badger's post, in addition to TVS, it is a superiour method, but the original point of a two part system in the first place was something compact that could be soldered right to the laser diode itself.

Makes me wish I had a DSO with logging capabilities instead of my POS analoge scope, I would love to see some responce/clamping time charts for myself rather then just what the part's datasheet and other assorted literature offers.

 

[Bionic-Badger]

If you look at the diagram itself at the end of the document, the whole design is pretty small, not larger than a LASORB at least. Only the MOSFET might be large, and only because we need higher currents than the laser ignition system would. For a portable system a TVS is probably sufficient; the MOSFET was added to prevent catastrophic damage to the TVS causing an open rather than a short.

 

[Bluefan]

Makes me wish I had a DSO with logging capabilities instead of my POS analoge scope, I would love to see some responce/clamping time charts for myself rather then just what the part's datasheet and other assorted literature offers.

I have a HP 54111D oscilloscope and a HP 8118A pulse generator, if you're curious enough to have something measured, I'm curious too. I've only once heard of a TVS before, I think it was even on this forum.

 

[rhd]

A little update -

The boards should arrive in a week or so. I ordered 15 (or maybe 30, I can't remember), and I have the parts from DigiKey to build all of them.

Before this "Protector" thingy (that's what I'm calling it) will be of any use to the community, we need really critical enthusiasts to bang on it a bit. If anyone wants to play around with the resulting thingy (and has the ability to actually evaluate it's effectiveness to some degree), let me know and I'll send you one.

The first "Protector" is for either RED or BLURAY diodes. It has a solder bridge to select which of the two diode's you're using. It also has the convenience of added through-holes for each diode lead.

And again, the deal with these is that basically I'll just post the files up for anyone to reproduce the boards (presuming we establish that there's some value to this * thingy*, and it works, etc)

Testers / Recipients / Brutal Critics:
- GBD
- rocket689
-
-
-
-

 

[Johnyz]

Nice PCB! I think it would be possible to enhance the design even more for protection during experimenting - e.g. a Zener diode to protect the driver in case the diode fails, backward current protection, etc.

 

[rhd]

The large diode is a reverse polarity protection diode.

 

[hakzaw1]

Very nice!!!

 

[Bluefan]

I'm interested in testing one of these, what are the possibilities of getting one?

 

[kiyoukan]

okay so im about to get a large amount of boards ran nearing the 1,000 i got some st drives boards being made then i got hopefully another driver have these been fully beta tested?
I might want to throw them on my panel im getting made.

 

[rhd]

okay so im about to get a large amount of boards ran nearing the 1,000 i got some st drives boards being made then i got hopefully another driver have these been fully beta tested?
I might want to throw them on my panel im getting made.

Nope, not at all. I'm still waiting on the 30 pc run from DorkBot.

You're welcome to the PCB file though, if you'd like to make them. That's the idea with these, they're total Open-source(?) - basically free for anyone on the forum to work with, develop, play with, change, etc. I can send you the BRD file if you'd like.

Where do you get your PCBs made? Is it cheaper than Dorkbot?