Blanking "speeds"

[mikkojay]

Hello All,
My name is Mike and I live in Omaha, NE. I have been "trolling" at this forum for quite some time now, reading into the wee hours when I should be sleeping! I'll save the formal intro for another time/place, but the topic of this thread is what made me come out of my shell. I am piecing together my first REAL system (hene and wobble motors as a kid). So far, I have some of carmangary's 30k scanners, and a LA Freak kit that I am anxiously awaiting in the mail. That leaves me in the market for a new laser(s).
The topic that has been keeping me awake as of late is BLANKING SPEED. I have read about the pros of analog VS TTL, so that is where I am leaning. The thing that has me stalled is that I cannot seem to find a lot of greens or reds, with analog blanking, that have a speed of >10k.
I am currently thinking of 100mw for green & 250mw for red, using analog control to balance the colors when doing graphics. I like this one:
MaXYZ Red on ebay
The blanking specs are great, but the thing that turns me off real fast on that one is lack of a warranty, but after reading the reviews, I would be comfortable dealing with them. Reputation seems to go a long way here.
Anyone know of a good green with the type of modulation I am looking for, or am I just being too paranoid over the significance of this spec? I just want things to be nice and tight when the light finally hits the wall.
Thanks for all the great info you guys have to offer- this forum is awesome!
~Mike

[buffo]

Hi Mike;

Welcome to PhotonLexicon! Always nice to see new members...

I am piecing together my first REAL system (hene and wobble motors as a kid).

Lots of people started that way (myself included), so no shame there.

I like this one:
MaXYZ Red on ebay
The blanking specs are great, but the thing that turns me off real fast on that one is lack of a warranty,

That seller is none other than our own Marconi, the guy that makes and sells the Maxyz modules. No doubt you've read a lot about his modules right here on PhotonLexicon. The lack of a stated warranty is due to the nature of a direct injection red laser diode. You can kill it INSTANTLY if you reflect the beam back into the diode at any significant power level. Because this is so easy to do, it's hard to offer a warranty. You end up going broke because of the mistakes of your users. Officially, there is no warranty for damage caused by back-reflection.

Now, having said all that, Marconi is normally pretty good about warranty repairs. A quick look under a low-power microscope will immediately show if the diode was killed by back-reflection. In those cases, Marconi will normally cut the user a break and offer to replace the diode at cost. Sure, you still pay shipping, but that beats buying another whole laser...

By the way, you do know that Marconi offers a discount (5 or 10%, I think) to PL members, right? Send him a PM and ask about it.

Anyone know of a good green with the type of modulation I am looking for, or am I just being too paranoid over the significance of this spec?

As a general rule (and I *do* mean general), a 10K analog blanking rate will work up to around 24Kpps, while a 15Khz blanking rate will be OK for 30kpps and up. However, my green is rated for 10Khz, while the blue is 15Khz. They both work well at 30Kpps, but the green is a bit slower. I notice it, but most people don't. The difference is very subtle.

You want at least 15Khz (faster is even better), but if you can't find a laser in your budget that supports at least 15Khz you can live with 10Khz... You may need to play with your color speed a bit though. There is also a delay circuit that you can incorporate into your projector that will compensate for different blanking speeds among your lasers. (I'm actually looking into installing just such a circuit in my projector.) Bill Benner of Pangolin is the one that came up with the design; search through the forums and you should be able to find his post where he linked to the Pangolin website to show the details of the circuit.

As far as a source for your green laser, have you looked at lasershowparts.com? The two guys behind that company (Dave and Aijii) are also members of PhotonLexicon and can answer any questions you may have about their lasers directly. Check out their listings - they've got some great deals...

Adam

[acrorezo]

Dear All,

I have issue with the power of my laser when I use the TTL/Analog blanking.

I have read "the retro-reflective blanking", is the best way if I don't want to lose power on a AOM. ( True, I have tried that, a waste power with the order 2 ... due to my bad technique to adjust Mr. Braggb )

But I can't find nowhere a simple scheme to explain how that work, how I can tune, good or entry range scanner for the blanking.

If somebody can just send a single line scheme to explain.

Thank you in advance

[steve-o]

What type/ kind of laser do you have?

[acrorezo]

I have a DPSS 532 nm, GL532H-1000, Scan-Pro 30K and LD2000 intro.

I don't know why I lose power when I do blanking with the LD2000 and this laser.

With the scope I see perfect squares 0-5 V and when I use a DC 5 V power supply on blanking analog/ttl laser I have the full power after 10 min. (warm up time).

I have asked Dave today about this problem.

[buffo]

Hi Acrorezo!

Welcome to PhotonLexicon. Here is a thread (with pictures) that shows you how to use a scanner and a retro-reflector to blank the beam.

Adam

[allthatwhichis]

Hi Acrorezo!

Welcome to PhotonLexicon. Here is a thread (with pictures) that shows you how to use a scanner and a retro-reflector to blank the beam.

Adam

2000th post!!!

[buffo]

Hehe... I didn't know you were watching that, Aaron! And you're right, that was number 2000. Sheesh - I've got to do something about this verbal diarrhea of mine!

Love the smileys dude...

Adam

[allthatwhichis]

Yea, you should really watch that... it looks to be a habit. You should look to me as an example of restraint...

[acrorezo]

Thank you very much Buffo,

It's exacly what I search.

But not found with the search function ...

Patrick