How would you like to talk over a laser beam? In about 15 minutes you can set up your own laser communication system using a cheap laser pointer and a few parts from RadioShack. The audio signal from a microphone varies the power feeding the laser, so that its brightness changes, following the shape of the original sound wave. At the receiving end, a solar cell or photo-resistor converts the oscillating light signal back into the original sound.
The communication is completely private, with no wire connection to tap into. Only you will be able hear what comes over the secret laser link.
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All of the component specifications listed appear correct to me.
What problems were you having?
This project is based on this one:
“http://sci-toys.com/scitoys/scitoys/light/light.html#laser_communicator”
and the kit can be found here:
“https://www.scitoyscatalog.com/product/LASERVOICEKIT.html”
The second link has the transformer you need.
Scitoys.com ships all over the world.
The whole kit is available here:
http://www.scitoyscatalog.com/product/LASERVOICEKIT.html
The transformer by itself is available here:
http://www.scitoyscatalog.com/product/XFORMR.html
Check the voltage required by your green laser, and the voltage actually delivered.
You’d still want the transformer to mix the signals.
But a pair of resistors would probably work also.
Can I use the audio output transformer with these specs?
AC resistance @10khz : 2KΩ-0-2KΩ (primary), 95Ω (secondary)
Inductance @10khz : 19.2mH-0-19.2mH (primary), 0.88mH (Secondary)
Turns ratio approx : 22:22:1
DC resistor approx : 39Ω-0-39Ω (primary), 1.5Ω (secondary)
If I understand you, you suggest to lower the full output of the radio by using resistors ? Right you are old chap ! What is your location ? I am calling you from Antwerp Belgium. So long !
Can I use some cheap earphones in place of the crystal earpiece? I have a pair that I don’t need and that’s easier than finding a place that carries the crystal kind…
I’m Confused. I can’t get the simple input circuit to work. When I add the transformer in series with the batteries the laser pen no longer works. Works A-OK if I short the transformer while it’s in the circuit. All versions of this experiment reference a 4.5v battery source but my pen is 3.0v. Does the laser type (4.5v vs 3.0v) or battery voltage make a difference? If so, you’d think this would have been mentioned along the way…
Thanks for help, Mike
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Hi, is the current in this setup AC or DC?
you can see the batteries so it is dc
I have problem, I did the laser communiucator but it noesn’t work, which is the problem?
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