No New Projects?

[mixedgas]

^ They're nice!
I was using a very very similar one today on a InSb detector.

I've got three of them. Two bigguns and a littleun.

Steve

[planters]

Thanks Steve! PM on the way. And by the by, we need to discuss this whole yellow thing.

Another issue I've thought about is what happens when you use more than the 3 primary colors in a projector? Take orange for example. If the RGB mixes some predetermined ratio of red and green to produce orange and now you incorporate an orange laser, does the program back off and run only the one source or does it combine true and synthesized orange to produce the output. What about reddish orange? Is any green used? And in these examples assume the lasers all have different maximum output power. Seams like a real mess or am I making this too complicated?

[White-Light]

Planters don't know what software you have but it isn't a problem in Beyond if you have it as there are more than 3 available colour channels. You can also set each colour up as pure or mixed even the primary colours.

[planters]

White-light,

Please re-read my post. I have Beyond and although I have build #546 and although this only supports 3 colors, that is not the question. I know there is a version that has or will be released that supports 6 colors, but that is also not the point. Let me set this example. 2W 635nm, 150mW 590nm and 2W 532nm and I want a 600nm equivalent color projected. How do you mix these? Do you blend the 2w lasers to produce 610 nm and pull this down to 600nm with the 590nm? You see there are an infinite number combinations of these three colors for the "same" output. How is this adjusted? How is the vast difference in PO between the lasers imported to the program?

[White-Light]

Planters, without giving too much away, that's where Beyond is clever. You can adjust the colour of any specific colour even the primaries then the others are calculated in between.

[masterpj]

A lot of this will depend on the outcome of some final testing that will be done this week and next week. The initial goal was to produce a driver that could deliver a maximum of 10 amps at up to 8.5 volts across the diode. This may have been overly optimistic, since the driver also needs to be rock-stable at very low currents (such as when driving a blu-ray diode at 100 ma, for example). The testing that will be done will determine if this is actually attainable or not. (Marc Rubin has modeled it in PSPICE, and it looks fine, but the proof is in the hardware...)

Also 10 amps requires *huge* traces. Look at the picture above and you can see that the ouput traces are pretty big. In fact, the distance between the pins on the output transistor is the limiting factor on how big those traces can be. We are reasonably certain that this layout can physically handle 10 amps. So as long as everything else works out, we should be OK. But worst-case, if we have to de-rate the current, we should be able to handle 8 amps for sure. (Which should be just enough to handle your IR-pump diode needs, Eric... )

The driver will run off either 5 or 12 volt supplies. 5 volts will be idea for reds and IR diodes with low forward voltage drops. 12 volt supplies will be required to power 445 blue diodes, blu-ray diodes, and the new 520 nm green diodes, because of the much higher forward voltage drop across the laser diode.

Of course, when running off a 12 volt supply (especially at high currents) you will need to be mindful of the power loss across the output transistor! There will be a lot of heat generated there, and if it's not properly managed, you will cook it. (There will be detailed information on this in the datasheet included with the driver.)

I have put several drivers on my oscilloscope and fed them square waves. I was quite surprised to see how much noise was present even on very popular hobbyist drivers. I think I understand why I've had so many failures over the years! I'll try to get some pictures next week to explain this further. But yeah, if you are running a diode right at it's limit, all it takes is a little noise and POOF! And there is more than just a little noise on the drivers I've tested.

Also, I should point out that this is not a new problem. Francesco Van Loon did a lot of research for Pangolin on this subject back in 2009, and my understanding is that every driver he tested exhibited problems of one sort or another. And he didn't test just hobbyist drivers. He also tested several commercial units that were quite a bit more expensive than anything you'd find for sale here on PL. But they all had flaws. That's what lead Bill to design this new driver in the first place.

All we have really done is to modify it slightly to support much larger output currents, and also to support higher forward voltage drops across the laser diode. The "guts" of the circuit is still all Bill's design; we left that part alone.

Also, I do need to thank Bill for agreeing to allow us to use his design. Without that, we never would have started this project. In addition, Mar Rubin (Kecked), Mo Ayoub (Daedal), and David Zurcher (DZ) have been very helpful in bringing this project to the finish line. Believe it or not, Mo and I first started talking about this nearly 3 years ago! We re-started the project in earnest back in October of last year, and it's taken us this long just to get to a working prototype.

But we are almost there. Just waiting on a few final components to arrive in the mail, and then we can start testing. Assuming all goes well, then by the end of next week we should be able to send the first batch off to be manufactured.

Adam

That driver sounds really promising.
Any estimate on its price? (like it wont cost more then ..... )

Regarding P3: I like this driver, however I'd love to see a version with the option of beam surpression.

Maybe introduce a P3+ or just add the beam surpression option to the newer batch of Flexmods if possible (whatever is easier and cost efficient).

[norty303]

2W 635nm, 150mW 590nm and 2W 532nm and I want a 600nm equivalent color projected. How do you mix these? Do you blend the 2w lasers to produce 610 nm and pull this down to 600nm with the 590nm? You see there are an infinite number combinations of these three colors for the "same" output. How is this adjusted? How is the vast difference in PO between the lasers imported to the program?

I would imagine that you set each colour appropriately in the advanced settings, using the mix you prefer.

So to simplify, if you want orange, and you have an orange module, use mostly orange, and add green/red mix to increase intensity (if you need it). Of course, you could choose to use just red/green mix and no dedicated orange module (but that would be silly)

I think the answer is 'the choice is yours how you get from A to B'.

This is why there are 3 tabs in the advanced settings, for high power, low power, etc. You can colour and intensity match, so you don't get big brightness spikes across the spectrum, or you can say to hell with the variations, I just want it as bright as possible everywhere.

[mixedgas]

In older six channel Pango products, it was just hook up and go. All colors just added more power.
Having one more color in the color gamut expands the color triangle area by about 20-25%, even if the power is low.
Most of us Ion guys love adding 568 yellow-green, 575 yellow, or 457 violet.

The violet really, really, expands the gamut. True yellow is a close second.
I imagine a 600ish color will also really, really, expand the Gamut.

I've seen 2 watt yellow-orange OPSLs used as the sole laser source in a outdoor beamshow. After seeing that, there is no reason to return to 532, ever.

Get LSX and avoid having mysterious color mathamagic....

Steve

[norty303]

Get LSX and avoid having mysterious color mathamagic....

Can you explain what you mean by that a bit Steve?

From my dablings with the Beyond advanced colour settings it's not really rocket science.
If you're not interested in even brightness levels across all colours, you just pick a colour you want to project, and then dial that in by increasing/decreasing the component colours until it looks right to your eye.
Once you've done this for the core colours, it transitions smoothly between them, using the setups you've done.
If you want to balance the brightness of the colours, you have to compare the outputs for the colours you've set up (I expect there's a test frame to make this easy - I haven't got that far yet).
In my head, its the most logical way of doing it. Until you tell it how much of each colour to mix, how does it know that 40% 532 and 100% 650 = 'that nice amber'?
I would imagine LSX needs 'telling' in the same way.

Does LSX have algorithms to know relative brightness of the used wavelengths, and you type in the power of each module, and it auto-compensates? Otherwise I can't see how it would know what to attenuate, and how far.

[planters]

Norty,

Well stated. Furthermore, what if you want a particular color that could be achieved by either mixing a pair of primaries or it could be generated entirely or in part by a single laser. Does it look better one way or the other? I've heard that more input colors will give a richer color saturation. If so how does that look in practice and if it does look better then the balancing in the color settings should probably max the nearest laser and add the bracketing lasers to make up any brightness deficit. It also suggests that the biggest gains will be by finding colors that nearly split the available primary colors.