fragile

You can say that again. supa fragile. On my first solar panel build, I turned a few cells to dust...with NOTHING. no pressure, barely touching them and poof.

 

Hi, I played with some of the cds spares I have from this project (spare part are profit, at least thats what mechanics say ) and the resistance I get with them illuminated is a range of 479-549 ohms (bounces a lot) and greater than 2000k when dark

 

You can use a green filter to be sure only green get through. That way ambient light won't have as much of an effect.
It should smooth your response.

 

I am also playing with a red laser because I can easily get a body and continuous (switched) laser in the form of a laser lever, with an adjustable tri-pod. I just don't know what the output of the laser level is. (as I said in an earlier post, the visible difference between the red and the green is astounding, the green is much brighter and a bigger dot) I don't know if that affects wavelength (the green is 520 nm and .5mw power)

 

Where do you get color filters?

 

You can use a clear piece of plastic and a magic marker if you have to. I've used the "blank" protective CD that comes in multi-packs of cds.. the spool packs. And use a green Crayola marker. The more 'coats' the darker the filter.

But you can buy lighting gels online. Even photography filters.

 

One other question I have with using PV cells instead of CDs is the target area. With the cds, I have to be so precise, I would like a target a little bigger, I think a gust of wind could knock this out of line. Is there a way to rig a commercial Laser detector (Think Cobra or whistler radar/Laser detector) to act as my detector and switch the timer? They are fairly inexpensive (40 bucks or so) but may need a larger power supply. Also the problem occurs that we solved with the optocoupler curcuit, I would need the switch to be open when illuminated (detecting) and need to close the switch in abscence of the laser light. Any thoughts?

 

As far as filters go, wouldn't the light be diminished by a filter? I need all the signal I can get. I was actually thinking of a reflector cone around the cds. What do you think?

 

Where do you get color filters?

any semi transparent green film would work, (similar to that red tape people use to put over their tail lights instead of replacing the broken lens, but green of course)...... there is also a type of plastic used to wrap fruit baskets and such, I see it mostly around the holidays though......


Is there any of those CDS' that fall below 200 ohms when lit, and hit around 2 megs or more when dark?

and as for the "dot" size, it could make a difference in intensity if one beam has a wider dot than the red, the smaller the dot, means the more focused the light beam is, sometimes those lens apertures can be turned (the lens holder is usually threaded on and locked into place with a dot of locktite thread locker or something) you could try turning it one way or the other to see if you can change the dot size by adjusting its focal point....... I retro fitted a Laser pointer with a DVD burner Laser diode and I was able to manually focus the beam this way to where I could pop balloons across the room with it

 

One other question I have with using PV cells instead of CDs is the target area. With the cds, I have to be so precise, I would like a target a little bigger, I think a gust of wind could knock this out of line. Is there a way to rig a commercial Laser detector (Think Cobra or whistler radar/Laser detector) to act as my detector and switch the timer? They are fairly inexpensive (40 bucks or so) but may need a larger power supply. Also the problem occurs that we solved with the optocoupler curcuit, I would need the switch to be open when illuminated (detecting) and need to close the switch in abscence of the laser light. Any thoughts?

We seem to be cross posting a lot tonight

If the receiver unit has some kind of LED indicator to indicate weather the laser is on or off, this could be used to tie in the optocoupler circuit to trigger the timer (remove LED and connect optocoupler's input directly to where LED was, 2 wires basically, and we could get rid of the transistor and only have to use the optocoupler to protect each device...)...... if not, with a handy multimeter (and a pot of coffee ) you might be able to find a "spot" on the inside to tie the optocoupler circuit into.......

B. Morse

 

Did you see my latest posts? (BY the way, you sound like a fun guy at parties(I can just see someone standing by a ballon and you explode them and the jump out of thier skin, could you heat a champaign bottle hot enough to get it to POP?)

 

I think the detector has a visual alert when detecting the presence of laser energy (led display) I don't have one here to look at but from what I've seen there is an audio that can be silenced and a visual alert.

 

Did you see my latest posts? (BY the way, you sound like a fun guy at parties(I can just see someone standing by a ballon and you explode them and the jump out of thier skin, could you heat a champaign bottle hot enough to get it to POP?)

Yes I seen your latest ones, I just answered one of them, anyway, the laser diode I used was not that powerful so probably wouldn't heat a champagne bottle enough to pop it...... I have been salvaging laser diodes from DVD burners to try and make a Laser Engraver for my CNC machine I am just waiting to tear into a Lightscribe DVD recorder to see how powerful those are (powerful enough to laser etch a design onto a CD!)

 

I think the detector has a visual alert when detecting the presence of laser energy (led display) I don't have one here to look at but from what I've seen there is an audio that can be silenced and a visual alert.

That would be great if it had either one, it would make it simple to "hack" it and connect the counter module..... That may be the best way to go for now to get a stable setup. (Why reinvent the wheel, when you can borrow one )

 

I don't think I need that much power. Anyway, what do you think of a aluminum foil reflector cone around the cds? Inside my detector casing I don't get much ambient light, if I make the cone real small, all the laser light should get captured and reflected into the cds, hopefully alleviating my aiming problem.

 

This cross-posting kind of gets confusing, Would I need to wire a curcuit with the optocoupler from the audio or visual alert outputs?

 

What about adding another laser pointer? That should double your intensity, hopefully solving the problem.

 

I don't think I need that much power. Anyway, what do you think of a aluminum foil reflector cone around the cds? Inside my detector casing I don't get much ambient light, if I make the cone real small, all the laser light should get captured and reflected into the cds, hopefully alleviating my aiming problem.

You could give that a shot. It should work in directing the beam / light onto the CDS....

 

The problem I am seeing has more to do with the accuracy needed shooting the CDS. The unit works fine, as long as the laser is pointed exactly right, but outside, with environmental conditions, I think i will need a bigger target, not as affected by jiggle. Maybe a silicon photodiode laser light detector (Optek part number OP913SL)

 

The problem I am seeing has more to do with the accuracy needed shooting the CDS. The unit works fine, as long as the laser is pointed exactly right, but outside, with environmental conditions, I think i will need a bigger target, not as affected by jiggle. Maybe a silicon photodiode laser light detector (Optek part number OP913SL)

I noticed the "jiggle" with my setup too, a little hand shaking at 50 + feet turns out to be a laser show across the room! Maybe a wider CDS would work, the optek part you posted above only has a .115" x .115" area, which is still pretty small...... maybe a lens of some sort, possibly a collimating lens to direct the light more onto the CDS.........