LASERs

Just came across these
http://www.mpja.com/Mini-LASER-Head-635nm-5mw/productinfo/19566%20LZ/
Think it'd be good for the transmitter in a laser harp or similar? Thinking like a ceiling to floor installation, or perhaps a 2D grid across the floor.

Supply Voltage: 3VDC
Current Drain: <40mA
Output: 5mw
Wavelength: 650nm
Aperture: 3mm
Lens: Glass
Shape: Dot
Connection: 2in. Wire Leads
Compact Size: Dia: 6mm L: 15mm Wt: .001

Body+board is 6mm diameter, 15mm long

LASER-Red.jpg

Seems pretty powerful (5mW). You can probably blind the cat with this thing. Any particular project in mind?

I'd suggest paying the extra dollar or two (or less?) and finding a module with a focusing lens. It doesn't appear that this one has one. Without the lens it's a bit of a luck that gives you a nice dot or a wide blob.

These numbers are saying the focus will be poor?

"3mm Aperure
0.8m Radians Divergence"

Didn't really have a project in mind, just thinking out loud about possibilities at the moment.
We do have 4 cats, I'll have to keep that in mind.
Maybe one of those boxes you can wave your hand in to make different sounds to be pet safer. Left/right, up/down, in/out.
Not sure what the algorithm would be, maybe in/out would be volume, and the left/right could be notes low to high, with octaves rising as you move low to high. Finger could be one note, more fingers more notes, either in same octave, or across octaves.
So I guess 13 up/down, 7 left/right, and 7 in/out?

What is the duty cycle of one of these LASER modules? Can they be on for hours at a time? Can they be switched on and off very fast?

Don't know, all I have is what's in the first post

This be a good receiver?
http://www.mpja.com/IR-NPN-Photo-Transistor/productinfo/17756%20QT/
Like having the output side of an optoisolator, the 2 pins would be the collector/emitter?

The wavelength is pretty far off. The first post show 650nm for the LASER and the link you posted shows the sensor to be sensitive to 880nm. Being pounded by a LASER, it probably won't be able to ignore it. :wink:

That's what I was thinking. I can't locate a datasheet for it tho to see how much it would drop off,

Any particular reason (aside from price) that you like that specific sensor? It's certainly small, and it ain't ugly I'll give it that. But your LASER module output is visible red, right? It doesn't look like there is any visible light filter over the die, so that seems to be a positive sign that it might work for you.

No reason, it just happened to be there.

CrossRoads:
Don't know, all I have is what's in the first post

This be a good receiver?
http://www.mpja.com/IR-NPN-Photo-Transistor/productinfo/17756%20QT/
Like having the output side of an optoisolator, the 2 pins would be the collector/emitter?

For a 5mW laser, I think almost any photodiode can be used :slight_smile: I have a 1mW one and I can just pick one photodiode in my college days and make a light trigger (for camera/flash) out of it.

I think some high power laser is pulsed, so maybe that is something to check.