How long does a laser pointer last?

I park my truck in the garage every night, but it's a tight squeeze with all the crap I've got in there. I was thinking of buying a couple of those cheap laser pointers on ebay, and setting them up to point at specific spots on my truck when I am in the right place. /ubbthreads/images/graemlins/smile.gif To make the wiring less complicated, I would like to just leave them on 24/7...but how long do they last? Do they burn out eventually, or are they more like LEDs?

just use a tenis ball hung from ceiling easier

LOL raggie !!
you're right after all ..
bernhard

It's STILL a good question though... and one that is now bugging me.

I would think the way to over come the issue would be to set up the laser with a motion detctor at the enterance to the garage. That way when you pull in it comes on for a minute or two then shuts off. I have seen low voltage lights set up this way at home centers for around $40. They would already have the converter you need to drop down to DC voltage for the laser. Plug in the motiondetector and then run small gauge wire to the laser. You would see the wire but if you paint it to match the wall it might look ok.
Patrick

They make laser things such as this specifically for this purpose...

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Patrick Hayes said:
set up the laser with a motion detctor

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Then you have a relatively expensive motion detector that is always on, so that your cheap laser pointer isn't always on. That only makes sense if you know that the laser pointer won't last long if it's always on.

So the question remains,
"How long does a laser pointer last?".

What kind of flashaholic would I be with a TENNIS BALL hanging from my ceiling? /ubbthreads/images/graemlins/twakfl.gif /ubbthreads/images/graemlins/tongue.gif

Yeah, I thought about a motion detector, but I would like to keep this relatively simple. If the laser lasts, say, 100,000 hours like an LED does, there would be no need for it. However, I have no idea how long a laser pointer lasts...

How about wiring to the light circuit that comes on when the door goes up or down?

And the question remains.

Besides, there are a number of other projects that could call for a laser diode running 24/7. Aquarium lighting, mini-"light shows" (have a reflective surface on a speaker cone and have the beam reflect off of that on to a ceiling)...

The problem is, how much time and money are you going to invest only to find out the diode craps out after a hundred hours?

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JJHitt said:
The problem is, how much time and money are you going to invest only to find out the diode craps out after a hundred hours?

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Yep, that's why I'm asking. /ubbthreads/images/graemlins/smile.gif I just bought 3 pointers, $8 shipped...

In my experience, the button cell pointers rely largely upon the internal resistance of the batteries to limit their current. Hooking one directly up to a power supply of the same output voltage as the open-circuit voltage of the batteries (4.5 volts for 3 cells) isn't that good an idea for this reason. The laser diode has a junction (light emitting surface) about the size of a bacterium, so it's pretty easy to let all the magic smoke out of one.

Laser pointers that run on AAA cells or larger are more forgiving, and would likely have the right resistor or power regulation circuitry in them, making them more suitable candidates for connecting directly to a power supply.

As for laser diode life, I don't know that, and I've never had one go out except in cases where my own stupidity caused it to. Not much help in that department, sorry. /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/jpshakehead.gif /ubbthreads/images/graemlins/frown.gif

Like someone said, they make these. I've seen 'em at Costco. Don't remember how much. But it's designed specifically for parking your car in a garage.

But, the tennis ball really is the best. I've been in over a hundred garages where they were in use and I used it when I reparked their car. I remember the first time I asked a customer what in the hell THAT was for?

Ditto the electric eye device at Costco...I thought they were $40 or less...

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Sigman said:
Ditto the electric eye device at Costco...I thought they were $40 or less...

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And laser pointers are $2 a peice. /ubbthreads/images/graemlins/smile.gif And how much fun would it be to buy something like this premade? /ubbthreads/images/graemlins/twakfl.gif

Well, certainly an interesting project!!

Some manuals for older (1996-1998?) red laser pointers I used to have stated 8000 hours.

The laser in a CD player has a lifetime ´round 2500h...not that much, is it?

well 2500 aint realy that bad .id guess other stuff would ware out first.like tracking of the puh

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The laser in a CD player has a lifetime ´round 2500h...not that much, is it?

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If his lasers last 2500 hrs each, then his $8 purchase should last one year. Not bad.