Good, of the shelf laser

[buffo]

Great job Max!

To sumarize then: the Flashback 3 is a controller. The EasyLase USB is a controller. They do the same thing - they receive signals from the laser show software on the computer (via a usb cable) and send analog signals to the scanner amps, and blanking signals to the lasers. That's about it in a nutshell. The FB3 *also* has the added feature that allow it to run independent of the computer and to display files that are stored on the memory card, but it's unlikely that you'll be using it like that...

If you mount the controller in a box that sits between your computer and your projector, then you need to run a 25 pin cable between the controller and the projector. (When you hear people talking about an ILDA cable, this is the cable they're talking about.)

If you mount your controller inside your projector, you won't need an ILDA cable. You'll solder the wires to a 25-pin plug inside the projector and just plug it into the output of the controller like Max explained.

Re: the green dot to the left of the first dichro in the picture you linked to... The dichro isn't perfect. Although it will transmit 95% of green light and reflect 99% of the red, you are always going to have some losses. The green dot is the 5% that didn't get transmitted and was actually reflected by the dichro. Yeah, that power is lost. Such is life. (Look very closely and you'll see antother greenish-yellow spot to the left of the second dichro where the beam reflects off that face too.)

Adam

[mliptack]

Thanks Adam for filling in where my knowledge isn't as good as I would like it to be, or simply where I skipped accidentally.

Graham, I hope I am simplifying this for you, let me know if you need any clarification. I will have to take some more pictures of my projector, I dont think I have posted any since I did my revamp on it (which was just basically just a wiring overhaul to clean it all up). Next up either the 200-300w blue or the 1 watt green!

[laserLips]

That's all excellent information guys, thanks a lot. Everything IS much clearer now cheers.

I'm really excited about starting this project and glad I've found such a supportive community.

Feel some what embarrassed asking these questions but I find it much more rewarding than searching through endless technical documents.

Was thinking about how expensive blue lasers are....Max,200-300 mw....that's gotta cost...

If I left the blue out for now would the the R and G make it an RGY laser?
Does the FB3 software take care of modulating the two lasers to make the Yellow?

Right thanks again guys for all the information. I'm going to search for my enclosure. I'll get a reasonably big one so I can fit other bits and pieces in later. I'll let you know when I've got one in mind...
Have a great day all.
Graham

[laserLips]

Oh and Max let's see some pics...

[buffo]

Feel some what embarrassed asking these questions but I find it much more rewarding than searching through endless technical documents.

Happy to answer questions... Don't be embarrassed. However, sometimes you can pick up a lot of knowledge by reading past threads where other people have asked similar questions. Not quite as booring as reading technical documents...

Was thinking about how expensive blue lasers are....Max,200-300 mw....that's gotta cost...

Yeah; well over a couple grand just for 200 mw. Blue is expensive.

If I left the blue out for now would the the R and G make it an RGY laser?

Yes. If you have lasers that support analog blanking you'll get a smooth range of colors from red to orange to gold to yellow to yellow-green to green. If you only have TTL blanking you'll get red, yellow, and green.

Does the FB3 software take care of modulating the two lasers to make the Yellow?

Yes. All controllers take care of modulating the lasers to give you whatever color the ilda file specifies.

In some cases, the software allows you to apply color correction to the modulation to adjust your color balance as well. This lets you tweak your colors so the yellow you see on the screen more closely matches the yellow displayed by your projector, for example.

For sure the Pangolin LD-2000 system supports this. Not sure if there is any form of color correction included in the FB3 software though. (To tell you the truth, I don't even know if Mamba Black has color correction either - and I actually own that software! Just goes to show you how much time I've been spending on my Pangolin system lately...)

Adam

[laserLips]

Adam, you say that I'll get a wider variation of colours if my laser support analog blanking, is this the same when I'm using an RGB system?

Adam you say "Blanking is easily accomplished by simply modulating the driver circuit". Can you elaborate on that? How do I modulate teh driver...Can the software do that for me?

Still hunting for some laser cases...seen some for about £2000.
Grahan

[wes]

Adam, you say that I'll get a wider variation of colours if my laser support analog blanking, is this the same when I'm using an RGB system?

yes.

ttl blanking is basically full on,or off so you can only "mix"colors at full intensity,limiting the resulting color pallet.
analog blanking allows you to vary the intensity of each color and thus get far more color possibilities.

Adam you say "Blanking is easily accomplished by simply modulating the driver circuit". Can you elaborate on that? How do I modulate teh driver...Can the software do that for me?

yes,the software does that.
but there are more details to it.
some analog lasers are faster than others.
and there is also a thing called rise time which is how long the laser takes to recover from low to full intensity.
people build delay circuits so all the lasers r,g,and b rise together and no "lag" is seen.

also,you need a regulated source of voltage for the modulation circuit.
going over rated voltage on the modulation circuit will fry your lasers.
you'll need more detail than i can provide on this question.

Still hunting for some laser cases...seen some for about £2000.
Grahan

jeze louise!!! you could build a whole projector for that price!!

[buffo]

you say that I'll get a wider variation of colours if my laser support analog blanking, is this the same when I'm using an RGB system?

Yes. Analog blanking will always give you more colors. So if you have a RYG system, analog blanking will give you a wider range of colors between red and green. For a full RGB system the difference is more pronouced when using analog blanking. You literally have millions of possible colors at your disposal. (By comparison, TTL blanking in an RGB system will only give you 7 colors.)

you say "Blanking is easily accomplished by simply modulating the driver circuit". Can you elaborate on that? How do I modulate teh driver...Can the software do that for me?

Ok - let's back up a bit. "Blanking" means turning the laser (or lasers) off so that the scanners can move to a new position without "drawing". If you use the pen and paper analogy, blanking is when you lift the pen off the paper.

Blanking is controlled by your software. The software reads the ILDA file and interprets which points need to be blanked. That information is sent to the controller. The controller then produces a signal on the blanking lines for each of the three colors (red, green, and blue) to tell the lasers when to turn on and off. This signal needs to be timed exactly right so that the lasers turn off just as the scanners are getting ready to move to the next spot. The software and controller work together to keep everything in sync. You don't need to do anything...

If you have analog blanking on your controller, then the blanking signals for each laser consist of a variable voltage (from zero to +5 volts) that corresponds to varying power levels from zero to full power. If you have TTL blanking, then the signal is either at zero or 5 volts, corresponding to off and on (at full power).

The METHOD by which your projector uses this blanking signal to actually blank the beam is up to you. If you are using a gas laser, your choices are limited. You can't turn the laser off and on very quickly because of limits on the power supply design and the physical limits of an ion laser tube, so you have to figure out some way to physically block the beam. You can use a 3rd scanner to do this (with a flag or mirror that rotates into the beam path to block it), or you can use an AOM or PCAOM. AOM's and PCAOM's both use a crystal to diffract the beam away from the output hole in the housing. The crystal changes it's refractive index slightly based on the input from the AOM/PCAOM driver module. So you connect the blanking signal from your controller to the input on the AOM driver, and it controls how the crystal refracts the beam to either let the beam pass through or to stop it. Again, you don't need to do anything. The driver is designed to accept the blanking signal from the controller.

Now, if you are using a solid state laser, you can still use the two methods above to blank the laser, but there is also a THIRD method that is *much* easier. You can modulate the diode driver itself. Remember that a solid state laser is going to have an electronic circuit that controls the current to the diode (or to the pump diode in a DPSS laser). This circuit can be switched on and off *very* fast. It can also be "throttled" up and down. You can control this circuit with the blanking signal from your controller.

When you buy a solid state laser, the specs should list whether the driver supports analog blanking or just TTL blanking. Again, analog is preferred, because it gives you a wider color pallette. But remember that BOTH your controller *and* all of your lasers need to support analog blanking for this to work.

Adam

EDIT: HA! Wes beat me to it by 1 minute! Good jub dude...

[laserLips]

Thast great thanks guys. Fully understood.
Iv'e looked but not sure weather LaserShowParts CNI laser offer analogue blanking.....it does say that Modulation isAnalogue, so does this mean that they do support analogue blanking.....does anyone if the FB3 supports Analogue blanking.
Graham

[buffo]

The terms modulation and blanking are used interchangably. So if you see a laser that supports analog modulation, that means it supports analog blanking, and vice versa. The CNI lasers that they sell at Lasershowparts.com are quality lasers that will serve you well.

The Flashback 3 controller does indeed support analog blanking, so if you decide to go with that controller you'll get the full color pallete we've been talking about. (For the record, the EasyLase USB controller that Mamba Black uses will also give you analog blanking; it's just more expensive...)

One final word: Sometimes you'll hear people talk about analog color... That's the same thing as analog blanking or analog modulation.

Adam