fb3 blanking voltage

[badger1666]

any one know what fb3 blanking voltage should be, is it the same as qm2000 0 to 2.5v if so that explains why my lasers are running at half power, why is it not 0 to 5v most lasers i have seen and mine need 0 to 5v anyone got any ideas of how i can get 0 to5v from the fb3 i want my lasers running at full power not 50% all my lasers use robins drivers so want 5volts blanking so far my experiance of pangolin fb3 has not been much fun i had better luck with my old alphalite even if the software did keep crashing starting to wish i never sold it

[Lasermad]

"my old alphalite even if the software did keep crashing starting to wish i never sold it "

Arghhh you sold it ! SHOCK HORROR ....... alphalites should never be sold they shoul be pased around like family heirlooms , rick puts such loving care into building those boards by HAND !

PAUL

[DZ]

badger, how are you measuring the blanking voltage? If your reply is with a multi-meter, then that may be the problem. If you have an o'scope, take a look at the blanking signal with that. The output should be 0-5V, same as with the qm2K, not 0-2.5V. Measure with a multimeter will only give you an average, and if the output is changing in anyway, then you wont see 5V on the blanking line.

[badger1666]

The output should be 0-5V, same as with the qm2K, not 0-2.5V. Measure with a multimeter will only give you an average, and if the output is changing in anyway, then you wont see 5V on the blanking line.

if thats so what this all about then cut and pasted from pangolin web site
0 to 2.5v now i am confused will play with scope on monday at work

QM2000 Pinouts

Signal name

Pin

NotesX+1 -5V to +5VY+2 -5V to +5VIntensity/Blanking +3 0V to +2.5VInterlock A4Connected to pin 17 inside the QM2000R+5Red, 0V to +2.5VG+6Green, 0V to +2.5VB+7Blue (typically 476 nm), 0V to +2.5VDeep blue +8Violet (typically 457 nm), 0V to +2.5VYellow +9Yellow, 0V to +2.5VCyan +10Brightest blue (usually 488 nm cyan), 0V to +2.5VZ+11Depth Z (not intensity), -5V to +5VNot connected12Shutter13 0V to +5VX-14 -5V to +5VY-15 -5V to +5VIntensity/Blanking -16 -2.5V to 0VInterlock B17Connected to pin 4 inside the QM2000R-18 -2.5V to 0VG-19 -2.5V to 0VB-20 -2.5V to 0VDeep blue -21 -2.5V to 0VYellow -22 -2.5V to 0VCyan -23 -2.5V to 0VZ-24 -5 to +5VGround25

[badger1666]

"my old alphalite even if the software did keep crashing starting to wish i never sold it "

Arghhh you sold it ! SHOCK HORROR ....... alphalites should never be sold they shoul be pased around like family heirlooms , rick puts such loving care into building those boards by HAND !

PAUL

sorry paul it did go to another photonlexicon user very very cheap it made the last few quid i needed to get the fb3

[DZ]

badger, your right, it use to be that way. When it was a true ILDA standard connector. Now though, its the Pangolin standard projector, which is better anyway. I can't say for sure if its identical on the FB3, but for the QM2K, it use to be that, you could run differential signals for color, since no one seems to have any lasers that run differential color, he added the ability on the card to short pins 18-23 to pin 25, that way pins 5-10 would output 0-5V. On older cards if you leave pins 18-23 floating, you will only get 0-2.5V, now though, he has them internally grounded to it will only output 0-5V. Since I'm not completely familiar with the FB3, it could very well be that its only outputting 0-2.5V, but I'd be willing to bet that he has the same setup on the FB3 as the QM2K. Try measuring pins 18-23 to pin 25. If you get anything other than 0V, then you may have to ground pins 18-23 to get the full 0-5V swing on pins 5-10.

[buffo]

Badger;

I decided to do some checking on your behalf. But first, let me say that you can often get much faster results (like, immediate results) by either sending an e-mail direct to Pangolin, or by picking up the phone and giving them a call.

Also, while I know that it's upsetting when you have a new toy and it doesn't seem to work right, it's really bad form to immediately assume that what you bought is junk and start bashing the company. Many people here are running the FB3 and they all rave about it. So before you assume that it's really a piece of crap, you really should investigate the problem a little more.

Having said all that, I called Bill Benner this evening and explained your situation. And he confirmed what DZ has already explained to you: You *can't* measure a color modulation signal correctly unless you use an oscilloscope. All Pangolin controllers output a modulated 5 volt signal for color control. Using a meter to measure this signal will, at best, give you some sort of average reading that may or may not be the slightest bit relevant.

While Bill was not willing to speak for every other controller on the market, he did say that there are sound engineering principles behind this practice, and most, if not all, controller follow these principles.

Second, the FB3 color output is identical to the QM-2000. That is, you will have 5 volts between R+ on pin 5 and R - on pin 18 when red is supposed to be at full intensity. (The same goes for the green signals on pins 6 and 19, as well as for the blue signals on pins 7 and 20.)

Also, Bill confirmed that the negative color signals (pins 18-20) are already connected to ground (pin 25) internally on the FB3, just like they are on the QM-2000. So there's no need to run any jumper wires. If you have the positive blanking lead from your red laser connected to pin 5, and the negative lead connected to pin 18, you have it wired correctly, and your laser is seeing 5 volts whenever the controller is calling for full power.

Also, each and every FB3 board is tested by Pangolin before they are shipped (just like the QM-2000's), so it is *highly* unlikely that there is anything wrong with your controller.

Now, as to why you are not measuring full power: There are a number of factors that could be affecting this. The first would be the color balance controls on your software (LA Studio). Unfortunately, I'm not familiar enough with the software to give you step by step instructions on how to adjust this, but the settings are there. And if you have them set incorrectly, the FB3 will intentionally reduce the voltage on the color signals. (That's how color balancing works.) So this would be a good place to start looking.

Another issue may be with the frame file you are displaying. Especially if it is a frame that you originally created with the Alphalite software. I, too, started with the Alphalite, and while it had some neat features, it also broke all the rules when it came to standards. Thus, a file created in Alphalite and then imported into LA Studio may have the wrong color palette, or may have additional blanking points, or any number of other artifacts that could interfere with the apparent brightness of the image.

Finally, there may be issues with the driver you are using - particularly with regard to your green laser. This is an outside chance, but you may have hit upon the perfect combination of blanking rate and color speed that corresponds with a jellybeaning weakness in your driver.

Bottom line: Contact Pangolin about the problem. Send Bill the frame file you were using to test your lasers with. Explain in detail all the test conditions, especially with regard to how you were measuring the laser's power output. (I assume you have a power meter of some sort?) List all the settings you've configured in LA Studio. And if you have access to an oscilloscope, then include the voltage readings you measure with it. Bill said he will gladly take a look at your problem and help you solve it. (He's cool like that...)

My guess is that you've probably got your color palette set wrong. And if that's the case, it's a very simple fix. Unfortunately, while I have the LA Studio software (it's free for QM-2000 users), I haven't had enough time to really learn my way around it. So I can't offer you much advice on how to trouble shoot this. But Pangolin can.

And in the future, don't be so quick to throw in the towel and complain that your new toy is a piece of junk. After all, if it really was a piece of junk, do you honestly believe that all of us would be singing the praises of Pangolin hardware? Trust me, they make good stuff.

Adam

[badger1666]

my bad sorry to all that i offended
well i taken the project apart and going to start again but before i did ,i changed the driver on the green back to it original ttl driver and displayed a fb3 image of loads of colored circles flying about and paused animation so it displayed them still the circles are not complete most of the circle is there but fades to a tail before its complete and they sit there randomly flashing brighter i tried different settings and even tried the green on the red and blue blanking signal still the same does not matter what driver i use the red does not seem to do the the fading off to a tail is the same on any image that i display which explains why when playing a file in yellow i get weird results ,starting off yellow and fading to orangy red took the green out sat on the table for some hours working fine as soon as i show it to the fb3 it start playing up does not matter what driver it using ???
so i shall rebuild projector with everything isolated from chassis and star earth every thing and see if that helps i do have a picture of the the weird
color thing will post later i had only used pangolin files so far as all my other suff plays really fast as soon as i upload on to fb3 so its not the files if i make fb3 project a single dot on the wall that will sit there flickering
and randomly flash bright so i hope the rebuild works out
again sorry to bill i know he makes good stuff that why i got it, its just worked so well before
regards
chris green

[buffo]

i changed the driver on the green back to it original ttl driver and displayed a fb3 image of loads of colored circles flying about and paused animation so it displayed them still the circles are not complete most of the circle is there but fades to a tail before its complete and they sit there randomly flashing brighter

Hmmm... This really sounds like a jellybeaning issue with your green laser. (A fairly common problem, unfortunately. I suffer from the same problem at times with my projector, which is why I'm in the market for a replacement green laser that supports faster analog modulation.)

the red does not seem to do the the fading off to a tail is the same on any image that i display which explains why when playing a file in yellow i get weird results ,starting off yellow and fading to orangy red

Yeah, that's very common. Direct injection red diodes turn on and off really quick, and as a general rule it's easy to modulate them. But a DPSS green is really hard to modulate. You can get all sorts of artifacts and non-linearities in the power curve as you play with the modulation speed.

Still, there is hope. You may need to adjust your color speed setting rather than your palette settings though. Color speed is the setting that allows you to sync up the points that the scanners are drawing with the color signal sent to the lasers. Speeding it up or slowing it down even a little bit can have a large effect on the scanned image. This may help your situation.

took the green out sat on the table for some hours working fine as soon as i show it to the fb3 it start playing up does not matter what driver it using ???

Yep - classic jellybeaning. The laser works fine CW, but when you start to modulate it you get all sorts of wierd effects. The physics behind this phenomenon are complicated, but it's related to non-linear thermal effects inside the head (specifically, with the Vanadate crystal and the KTP crystal).

Interestingly enough, the guy that invented the DPSS laser once gave a lecture where he told the audience that it was *impossible* to modulate a DPSS laser directly. It had to be either on or off, and you'd need to use an AOM or some other device to modulate it externally. Of course, we now know that this is not strictly true, but it just goes to show you how difficult it really is to modulate a DPSS laser accurately.

so i shall rebuild projector with everything isolated from chassis and star earth every thing and see if that helps

No - no need to go that route just yet. There are other tests you can perform first. I'm sure Bill will have some suggestions.

i do have a picture of the the weird color thing will post later

Good. That will help a lot.

i had only used pangolin files so far as all my other suff plays really fast as soon as i upload on to fb3

Plays fast? How do you mean? It could be that you've got your scan speed set really high (higher than you had it set with your alphalite), and as a result the color signals are also running faster, and thus you've run up against the blanking limit for your green laser. You want your scan speed to be set at 30Kpps, assuming you've got 30K galvos that is. If you have 40Kpps galvos, I still suggest you run them at 30K. You'll get a wider scan angle, plus all the artwork is designed to be displayed at 30K anyway. Also, 30Kpps is about the limit of what the current crop of DPSS laser drivers can support in terms of blanking speed.

For what it's worth, I have a laser that blanks just fine if I'm running the projector at 20Kpps or slower. But when I crank the speed up to 30Kpps, the laser starts to jellybean and I lose power. At 40Kpps the laser runs at maybe 20% of it's rated power! So jellybeaning is a big problem.

One way to get around it is to always scan at 30Kpps or slower. Another is to play with the color speed settings. And finally, sometimes it's necessary to replace the laser with one that has better modulation characteristics. I need to change the green laser in my RGB rig for exactly this reason. It's OK when running TTL, but running analog causes it to jellybean terribly, and I get the half-circles and tails you mentioned above.

Since the Alphalite only supports TTL color signals, while the FB3 has true analog color, the problem may be that your green laser's driver is just not very good at analog modulation. Which means that the jellybeaning problem has always been there, but it wasn't as easy to spot with the Alphalite's TTL-only output. (Like I said, this is a common problem.)

if i make fb3 project a single dot on the wall that will sit there flickering and randomly flash bright

Funny thing: displaying a dot doesn't always mean that the laser is on all the time. Usually, there will still be blanking going on. (Wierd, I know, but that's the way projectors work.) Bill can elaborate more on this...

its just worked so well before

I understand your frustration, Chris. Give it some time, and I'm sure between the members here, and Bill and his group at Pangolin, we'll be able to come up with a solution. Hang in there.

Post some pictures, then give Bill a call at Pangolin once you've verified your voltage levels with an Oscilloscope for your own curiosity. He can direct you from there. However, my feeling now is that we're looking at a jellybeaning problem, and while there are a few settings you can tweak to make it better, the definitive solution is to replace the laser with one that supports better analog modulation.

Adam

[badger1666]

thanks for taking the time to explaain all that
so is it the laser its self thats the problem and not the driver because robins drivers are good to a very high frequency ? i did notice when setting up the output power of the green if i cranked it upto 1amp drive the beam jumped to three times the size what happening there ?
dave has some green 150mw analog lasers at a good price
http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWA:IT&ih=022
do you think this one will be ok
regards
chris green