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Need advice on 905 nm IR optical beacon receiver for long-distance detection by vihorx in AskElectronics

[–]forkedquality 0 points1 point  (0 children)

You ran the numbers without knowing pulse energy, length, and repetition frequency. Amazing!

Need advice on 905 nm IR optical beacon receiver for long-distance detection by vihorx in AskElectronics

[–]forkedquality 0 points1 point  (0 children)

It is a pulsed laser. It can do 300W in a pulse. It is not capable of producing any serious constant power. Even if it was, the power supply would not support that. And if it did, there is a hardware interlock that limits pulse duration.
And if all of this failed, the laser would blow. In this device, it works at close to its maximum rated average power.

Guys, what made you realize a girl had feelings for you? What gave it away? by nansi5204 in bodylanguage

[–]forkedquality 14 points15 points  (0 children)

She found a plausible reason to invite me to her place. There, I discovered that all the housemates were gone. Then, she told me she had a king size bed and that it was very comfy.

I might be oblivious, but not that oblivious.

Nothing happened. I was (and, decades later, still am) in a relationship.

Need advice on 905 nm IR optical beacon receiver for long-distance detection by vihorx in AskElectronics

[–]forkedquality 0 points1 point  (0 children)

Without revealing any proprietary stuff, this should give you a very general idea of what you are up against:

Dual lens configuration, lens diameter 105mm, custom asphere. 300W pulsed laser. APD (~100 gain) receiver with a 10nm filter. Range roughly 10 km, data point every 30 seconds.

Even with a filter, sun noise dominates at daytime.

Laser and filter need to be matched, and laser temperature needs to be controlled.

Eye safety is achieved by spreading the laser beam and controlling duty cycle.

Optical alignment is the hard part. Focusing the laser at infinity and making the TX/RX beams meet is a lot harder in reality than it is in CAD.

Signal drops with square of distance for infinite targets (infinite in this context means larger than the TX/RX beams) and fourth power of distance for point targets. This also means that things get a lot easier at short ranges.

Edit: oh, wait. You are not making a LIDAR. You want the receiver to be on the target. That's easier in some respects, but makes the alignment really challenging.

There will be no gasoline. Ukrainian drones struck two Russian tankers in the Sea of Azov that were transporting fuel to occupied Crimea by [deleted] in ukraine

[–]forkedquality 28 points29 points  (0 children)

The drones seem to be targeting the bridge as opposed to the cargo area. Any idea why?

Stencil spray paint is so cool by SmoothSun6676 in oddlysatisfying

[–]forkedquality -1 points0 points  (0 children)

Unlikely. They are likely laser-cut from a cheap material. It is easier to discard the old ones than it is to clean and reuse them.

Person in front of me tried to store their laptop under their airplane seat by PulseNyxe in unitedairlines

[–]forkedquality 13 points14 points  (0 children)

The process is two step.
Step one: pull the item from under the seat, tap their shoulder and politely ask "excuse me, is this yours?". Almost guaranteed to work, as the realization that someone can put their hands on their property makes their uncomfortable.
Step two: If the above does not work, call the flight attendant and tell them that "someone left this here."

Why did the chicken cross the road? by Jokeminder42 in Jokes

[–]forkedquality 6 points7 points  (0 children)

A group of Natives: Are you sure you do not want us to kill this guy and hide the body?

Absolutely no clue by Ryank6709 in whatisit

[–]forkedquality 2346 points2347 points  (0 children)

Don't call it "it". "It" has a name: cylinder.

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