New Video

[MICKEY S UK]

If the sticking point now is the TEC driver this may be an option:

http://www.photonlexicon.com/forums/...iver-%29/page3 post #68 advertises a simple TEC controller.

Bbe is the maker and has produced great quality drivers and seems to have the skills to design and manufacture something suitable.

Dave lasershowparts says he has a design that need putting together.

I have looked at this myself which has been a good learning experience.

I have an arduino nano reading temp via NTC, reporting over usb serial to arduino IDE. It is PWM driving an led @ 250khz so brightness responds to temp. 250khz seems to be a good compromise frequency, needing maybe 6uh inductors to filter the PWM. Next step is to learn more about the TEC driver part. LCD screens/buttons for control are easy.


This thread covered a lot of ground-

http://www.photonlexicon.com/forums/...big+tec+driver

@Planters - Every video you make is facinating and the fact that you are a non commercial entity sharing knowledge is refreshing. If anyone here doesn't want to see tens of watts of red they're on the wrong forum. Loving your work.

[planters]

I knew it. There HAD been extensive discussions about TEC controller on this forum. I just couldn't recall where. I remember BBe and his drivers as well.
The controllers are indeed the sticking point. I have already laid out a significantly more compact beam path and although the P73s work, there might be better diodes for this application. I will check the line width of the Oclaro 700mW multi-modes, the Mitsu 300mW G71s and both Oclaro and Mitsu will probably be coming out with new high power diodes by Photonics West.

@Planters - Every video you make is facinating and the fact that you are a non commercial entity sharing knowledge is refreshing. If anyone here doesn't want to see tens of watts of red they're on the wrong forum. Loving your work.

That's why I do it. Thanks.

[JohnYayas]

I have watched a handful of your videos and although I am extremely impressed by your knowledge of the material, I am equally impressed by your craftsmanship.

[planters]

I have watched a handful of your videos and although I am extremely impressed by your knowledge of the material, I am equally impressed by your craftsmanship.

Thanks. One reason I put a lot of effort into the engineering of the system/components is because the effect may be small or there may be a skeptical audience and I don't want the property to be blurred by a sketchy optic or a shaky mount. Andy had questioned my choice of multimode diodes when Kvant does not use them. When you try to do things outside of the box you need a good foundation if you are going to draw others to join you with enough enthusiasm that really new things can be created.

[hakzaw1]

awesome thread one to sub/link forsho.

thanks

[tribble]

Others have sung your praises so eloquently above at this hour I can only find it in me to say I agree with all of them, another remarkable video of another remarkable effort, for which I thank you heartily! Fine, enviable work.

[lightlinked]

so could you put a second peltier at the other end to heat the array to maintain the thermal gradient when the diodes are off or at partial power? (during modulation)
You could proto a controller real quick with an arduino and the PID library plus some k probe amps + 2 power fets to control the peltiers.

[planters]

so could you put a second peltier at the other end to heat the array to maintain the thermal gradient when the diodes are off or at partial power? (during modulation)

Pumping each end was an early consideration, but it is now clear that the thermal bar technique is a bad idea. The mass of this bar makes thermal stabilization on power-up way too long a process. The gradient from one end of the bar has to be significantly larger than the gradient seen by the mounted diodes and this wastes the available gradient that could allow better spacing of the diode wavelengths or the addition of more diodes. Modulation will be in the kHz range and even the small brass diode mounts have way more than enough thermal inertia to bridge (stabilize or buffer) this modulation induced heating.

You could proto a controller real quick with an arduino and the PID library plus some k probe amps + 2 power fets to control the peltiers.

My son could. It sounds like you might be able too, but this is not an area in which I have much skill. A 4 channel or maybe a handful of two channel TEC controllers with 6-8A and say 24V, H bridge (bi-directional) heating and cooling is needed. I could take it form there and construct a compact, powerful, corrected red module using individual TEC stacks. My only issue is whether to go with the G71s or wait for Photonics West and the possibility of some newer and more exciting diodes from Oclaro and Mitsubishi.

[steve-o]

Another great vid Eric. This concept should indeed drive to multi watts of red. I don't know if the enthusiasm is waning due to cheap chicom projectors, or if we're just waiting for a 10w 638 diode. In the past (very) few years we have seen staggering increases in power of red, blue and now green diodes. It's amazing. The red 660 which we all used to have (because it was the only thing on the market back in the early days of diode lasers) had been replaced with 638 diodes which I remember dropping >$200 ea. for early mitsu 635nm 150mw multimode, so, while combining using WDM (which is fascinating and I really enjoyed your video of that method) it might just be simpler to wait until the laser diode power levels cap off and reach their upper limitation. I know that I'm tired of combining diodes just to find out that a new higher power diode is on the horizon, and all that fabrication/ hard work was for naught. On the other hand, if 10 watt diodes do appear we can all use your method to combine 3 for 30W of red to project on those mountain tops! That would be great

[planters]

On the other hand, if 10 watt diodes do appear we can all use your method to combine 3 for 30W of red to project on those mountain tops! That would be great

This reminds me of the response I made above about whether this was interesting. The reds will undoubtedly continue to evolve and the power will increase, but at least for me, new run of the mill projectors are not worth building. The CN manufacturers will get a hold of the latest diodes just about as soon as you will be able to order them and so the projectors from CN will remain similar to the ones we build if they are diode limited. Your projectors and my projectors will be better than the CN imports, but they take time. Techniques like multiplexing and my spatial filtering require out of the box engineering and additional expense, but could allow you or me to build literally the world's most powerful projector...literally. That is really exciting and makes me start visualizing new projects, new uses.