Combining Diodes with Different Power Ratings

[jjspike]

I will be posting questions as I come to dead-ends in my browsing. I cannot seem to find any threads that discuss mixing diodes, having the same wavelength (sames series), with different power ratings. For example, would I be able to combine 2 Mits 500mW 638s with 2 Mits 300mW 638s? If so, what would be the best way to accomplish this?

Cheers!

[astatic]

The quick answer would be, yes.

What would you need?
When the diodes run on a different current you need more drivers, Thomas alias Badpip sell drivers with 2 or 4 channels which could be setup for different currents.

Why would you mix diodes of the same wavelength with different powers?
I could imagine you would mix different wavelengths, some people do that to get a better color palette.
I do not get the point why you would do that?

[jjspike]

Thanks for your reply. I was wondering if this was a possible way of obtaining a more precise color ratio. I was thinking about using a 1 watt green with 2, 500mW and 2, 300mW reds. Please remember that I am totally new to this and still have to learn the ins-and-outs.

Cheers!

The quick answer would be, yes.

What would you need?
When the diodes run on a different current you need more drivers, Thomas alias Badpip sell drivers with 2 or 4 channels which could be setup for different currents.

Why would you mix diodes of the same wavelength with different powers?
I could imagine you would mix different wavelengths, some people do that to get a better color palette.
I do not get the point why you would do that?

[astatic]

When combining 2 x 500mw 638nm and 2 x 300mw 638nm you will get somewhere around the 1.3/1.4w 638nm (approximate), it depends on what kind of collimator optics your using and if your going to use correction optics which i think you will.
But what about blue?
If you want to have a RGB projector your going to need some blue also.
When having 1w 532 (green), 1.3/1.4w 638nm (red) and 1w 445/450 (blue) the colors will be off balance for white, you need a little more blue and a little less red to get a "balanced white", check some other topics to see where you lay your priority, more power or a better balance in colors.
It also depends where your going to use this projector for, as i see the powers it think it will be a show projector for beams and maybe some graphics, because a quality graphic projector needs nice an tight beams and doesn't need these powers.
They also need faster scanners which have smaller mirrors, and because you use high power multimode diodes the beam will be wider and so the beam won't fit the scanner mirrors anymore which results in allot of power losts.

But to point you in the direction for your red:
I know Dave has a set complete set for the mitsubishi 638nm wavelength:
- Collimator lens F2
- Diode mount
- a pair of cylindrical lenses with mounts

Give him a PM.

[jjspike]

Hi astatic,

I will be using a single M140 for the blue. I will dial-it-down a bit from the maximum current rating as I do not think that much blue will be required. As for scanners, I will start the DT40 wides as I do not want to upgrade a month down the road. I would like this for beam shows however the ability to project is a must. I am not too fussy about projection accuracy at this point however the time will come. Thank you for the optics link. I have seen these however I was unsure if they were for me. It looks like I am on the right track with some of my assumptions however I like the reassurance.

Thanks again!

When combining 2 x 500mw 638nm and 2 x 300mw 638nm you will get somewhere around the 1.3/1.4w 638nm (approximate), it depends on what kind of collimator optics your using and if your going to use correction optics which i think you will.
But what about blue?
If you want to have a RGB projector your going to need some blue also.
When having 1w 532 (green), 1.3/1.4w 638nm (red) and 1w 445/450 (blue) the colors will be off balance for white, you need a little more blue and a little less red to get a "balanced white", check some other topics to see where you lay your priority, more power or a better balance in colors.
It also depends where your going to use this projector for, as i see the powers it think it will be a show projector for beams and maybe some graphics, because a quality graphic projector needs nice an tight beams and doesn't need these powers.
They also need faster scanners which have smaller mirrors, and because you use high power multimode diodes the beam will be wider and so the beam won't fit the scanner mirrors anymore which results in allot of power losts.

But to point you in the direction for your red:
I know Dave has a set complete set for the mitsubishi 638nm wavelength:
- Collimator lens F2
- Diode mount
- a pair of cylindrical lenses with mounts

Give him a PM.

[swamidog]

dt40w's will actually do quite a decent job on graphics as well as beams.

for example: https://www.youtube.com/watch?v=eqqBG-F0BWQ

Hi astatic,

I will be using a single M140 for the blue. I will dial-it-down a bit from the maximum current rating as I do not think that much blue will be required. As for scanners, I will start the DT40 wides as I do not want to upgrade a month down the road. I would like this for beam shows however the ability to project is a must. I am not too fussy about projection accuracy at this point however the time will come. Thank you for the optics link. I have seen these however I was unsure if they were for me. It looks like I am on the right track with some of my assumptions however I like the reassurance.

Thanks again!

[Bradfo69]

I'll add a +1 for the DT40 wides too. LOVE them. (And I also have 6215's and Eye Magics.) You should be pleased with them.

I differ slightly on my estimates of power mixes for a crisp white but, we've probably all got our own opinions and they're all fairly close.

[jjspike]

Can I specify the mirror size when I order my DT40's as my home brew beams may not be the tightest?

dt40w's will actually do quite a decent job on graphics as well as beams.

for example: https://www.youtube.com/watch?v=eqqBG-F0BWQ

[Bradfo69]

I don't think so. The mirrors are: （X）5X10X0.8mm （Y）5X16X0.8m

DT 40 pros have two size options though. The trade off is scan angle. If you're more into beams, stick with the wides. They still have decent graphics performance when you need it.


DT40 pros with a large mirror option is your real sweet spot between the two though.