RGB Mixer setup

Alright guys, I've been thinking about this for a while and I think I'm ready. I still need to save a little bit more but what do you guys think?

Green laser: 250mw 532nm DPSS Green Lab Laser Module With TTL - eBay (item 120692620405 end time Apr-01-11 18:17:19 PDT)
Blue laser: Real 1W 445nm laser module/focusable/TTL [OL-445-1W] - $186.00 : Welcome to O-Like.com, Your source for laser products
Red Laser: 1W/1000mW Red laser module/TTL and Analog modulation [OL-R-1W] - $369.99 : Welcome to O-Like.com, Your source for laser products
Mirror: RGB laser systerm combine optical lens /2pcs in a pack [OLRGML] - $25.00 : Welcome to O-Like.com, Your source for laser products
Mirror holder: RGB laser systerm lens holder/frame/2pcs in a pack [OLRGBF] - $7.99 : Welcome to O-Like.com, Your source for laser products

I was thinking to just mount it all on a sheet of MDF.

You're just going to leave them on full power all the time?

No, since they all have modulation I can mix the power outputs of each correct?

Prototype said:

You're just going to leave them on full power all the time?

Click to expand...

You'll need a DAC and software to take advantage of the modulating capabilities of the lasers.

Sorry but I don't understand. I just wanted a simple setup where I can turn a knob for different power outputs for each. Would this not work?

If you used LM317 style drivers I think it would, but with lasers with modulating drivers, they're usually controlled via a DAC and software.

I know that the blue has a knob for power output. I don't know about the red and green.
I thought that was what Analog modulation meant...

There are two kinds of modulation when considering a projector setup. Analog and TTL. Analog modulation takes an input of 0-5v on the modulation port which then depending on the voltage sets the lasers intensity. Consider a color palette in a program like photoshop. When choosing a color you can actually see the RGB ratio that makes up that specific color, the same principle is applying to analog modulation. The advantage with analog modulation is that you (in theory) can create millions of colors. In real life however its a different story. Not all lasers work well with analog modulation. The threshold for lasing and max output, without damaging the laser, may not be far enough apart to actually have a well working intensity span.

TTL modulation usually takes 0-5v as well, however when 0 is supplied the laser is turned off and when 5 is supplied the laser is turned on. Well it can be less than 5, but as a rule 0 turn it off and at a given value > 0 the laser is turned on. This kind of modulation works well, but it will only give you the possibility of 7 colors: Red, Green, Blue, Yellow, Purple, Cyan and White. To get a white beam the intensity needs to be set on each laser to make a correct ratio between the colors. As a rule of thumb its somewhere around 1 x green, 2 x red and 3-4 x blue. Example 100mW green, 200mW red and 300-400mW of blue/violet. What you should be looking for is a constant current (pot adjusted), voltage regulated driver with either TTL or analog modulation.

Regarding the mirrormounts you have choosen from O-Like.. I thibk it can be hard to adjust the beams to combine perfect when using those mounts. You have no possibility to adjust any of the axis which means that your adjusting will have to be done at the laser module. This will be difficult to setup and adjust.

Best regards

You can do what you want to accomplish.. RGB color mixing, using knobs to set levels, with TTL modulated lasers by building fairly simple drive circuits to control the modulation pulses. It will work fine so long as your not waving the beam around. The knobs would basically control pulse width. Not moving it will work fairly well. If you start waving it around, the pulsing would probably be fairly evident though.


To do what you want, it would be easier if you used lasers that supported analog modulation. Then all you would need would be a 5V source and 3 potentiometers.

All of them do have analog modulation I believe. So this setup would work?

Also, do you have tracking info for my lens'? :san:

qumefox said:

You can do what you want to accomplish.. RGB color mixing, using knobs to set levels, with TTL modulated lasers by building fairly simple drive circuits to control the modulation pulses. It will work fine so long as your not waving the beam around. The knobs would basically control pulse width. Not moving it will work fairly well. If you start waving it around, the pulsing would probably be fairly evident though.


To do what you want, it would be easier if you used lasers that supported analog modulation. Then all you would need would be a 5V source and 3 potentiometers.

Click to expand...

If they support analog modulation, then yes it would work. And no I don't. The cheap no frills shipping is first class mail, though for the distance, I don't see why they shouldn't be there tomorrow or thursday. Friday at the latest.

Ok thanks, I ordered like 14 from rayfoss a few weeks ago and they still haven't arrived. :yabbem:

qumefox said:

If they support analog modulation, then yes it would work. And no I don't. The cheap no frills shipping is first class mail, though for the distance, I don't see why they shouldn't be there tomorrow or thursday. Friday at the latest.

Click to expand...

qumefox said:

To do what you want, it would be easier if you used lasers that supported analog modulation. Then all you would need would be a 5V source and 3 potentiometers.

Click to expand...

^^^^^^^^^^^^^^^
This
And avoid those mirror "mounts." You're going to want them more adjustable than that. Especially if you are going to mount it on MDF, the laser positioning and the mirror positions are going to "drift."

I would recommend that you use a good aluminum plate for the base in place of the MDF. The MDF will "flex" AND the plate is part of the heat sink

You are spending $900 on lasers. Don't scrimp on the components that will let you use them correctly

With 1W of 650nm you are going to need;
~270mW of 532nm
and
~230mW of 445nm

Those numbers are figuring efficient (and correct) dichros

Peace,
dave

Thanks dave,
What can I buy for mirror mounts?
Also, I thought that the ratio for RGB was 4:1:2
I was planning
1W red
250mW green
500mW blue.

daguin said:

^^^^^^^^^^^^^^^
This
And avoid those mirror "mounts." You're going to want them more adjustable than that. Especially if you are going to mount it on MDF, the laser positioning and the mirror positions are going to "drift."

I would recommend that you use a good aluminum plate for the base in place of the MDF. The MDF will "flex" AND the plate is part of the heat sink

You are spending $900 on lasers. Don't scrimp on the components that will let you use them correctly

With 1W of 650nm you are going to need;
~270mW of 532nm
and
~230mW of 445nm

Those numbers are figuring efficient (and correct) dichros

Peace,
dave

Click to expand...

bhwollen said:

Thanks dave,
What can I buy for mirror mounts?
Also, I thought that the ratio for RGB was 4:1:2
I was planning
1W red
250mW green
500mW blue.

Click to expand...

That is the ratio for 473nm blue. You're getting a 445nm blue.
My numbers are from Chroma.

You are going to want something like this:

Thorlabs Adjustable Iris, 1 inch Mirror Mount and Base - eBay (item 270715022360 end time Mar-13-11 14:12:34 PDT)

It would be even better if they were three-way adjustable, but that is the first I came across when quickly searching eBay

Peace,
dave

I understand now. So with the lasers I listed if I just play around with the power I would be able to get white correct? Also what is a better alternative to MDF. Are those Combining mirrors good? or is there a better alternative? Sorry for so many questions. You just know everything :bowdown:

daguin said:

That is the ratio for 473nm blue. You're getting a 445nm blue.
My numbers are from Chroma.

You are going to want something like this:

Thorlabs Adjustable Iris, 1 inch Mirror Mount and Base - eBay (item 270715022360 end time Mar-13-11 14:12:34 PDT)

It would be even better if they were three-way adjustable, but that is the first I came across when quickly searching eBay

Peace,
dave

Click to expand...