Any experience with these cheap Analog RGB modules on eBay?

[JohnYayas]

Can you elaborate more on the modulation issues? Seems like modulation of a diode laser would be pretty hard to mess up other than at the thresholds of lasing.

[james]

[cfavreau]

Thanks James!

Re: Lasing / modulation quality.

I found them to not be as linear as I would like a laser diode to be. For instance the greyscale frame that people sometimes test with begins with not all colors coming up at the same time (not quite white then) and there doesn't seem to be as many graduations. Adjusting for this in software helps a bit but doesn't cure the issue. For the price I cannot complain.

[TeraHertz]

Hitelmnstr, I believe I bought that exact RGB laser a few months ago for a DIY projector build. The module I received does feature analog modulation (see photo of a projection with the laser). I do agree with cfavreau though, the modulation isn't very linear.

If you are still considering buying the laser, I would reach out to the seller and explicitly ask for the analog version. The same seller mistakenly sent me a laser with a TTL modulated driver in a previous purchase, and when I reached out they said they have both TTL and Analog drivers for many of their models.

Hope this helps,
THz

[TeraHertz]

Actually, I checked my ebay history and I bought a very similar laser (100mW instead of 500mW), from a different seller. Here is the one I bought: https://www.ebay.com/itm/11371630413...53.m1438.l2649

I recommend specifically requesting the analog driver version, since in the photos you can clearly see that is a TTL driver.

Best,
THz

[cfavreau]

Here is a picture of the Ebay auction (from my past purchases page):

http://http://www.fab-favreau.com/st...seFromEbay.png (can't put a picture in this post for some reason... complains about too many characters...)


That picture is from the last 2 I bought. The seller does not have a 400mW module anymore however they do have a 1W one. The first 2 I bought I think I got from a seller called TechHood however the first time I bought an "Analogue" one it turned out to be TTL modulation however the second one I bought was in fact Analog modulation. I like the suggestion of contacting the seller first to make sure it is in fact Analog modulation.


Another thing that I saw that was different from seller to seller is how the mirrors are mounted. Some are just glued in place on posts and others are mounted on adjustable mounts (as pictured above). The adjustable mounts are glued too however it is much easier to realign those. Also note that even though the picture above shows the laser with no cover it did come with a cover.


I paid about $55 a piece for the Analog lasers.

[mixedgas]

Freddie M. had a degree in graphic fine arts.
Brian May has a PhD in Astrophysics.

Not quite the lazing he intended, but it works for me.

Gilmore and Mason have Pilots Licenses, hence "Learning to Fly" , which is mostly a Gilmore creation based on a concept by Nick Caro



Steve