tag:blogger.com,1999:blog-5096278891763426276.post5058576647529174357..comments2024-03-13T19:12:58.863+02:00Comments on absorptions: Voice over laserOona Räisänenhttp://www.blogger.com/profile/08764440174916554983noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-5096278891763426276.post-76725678755228185182020-07-23T03:41:18.246+03:002020-07-23T03:41:18.246+03:00Michael Fletcher's site is now at
https://73.f...Michael Fletcher's site is now at<br />https://73.fi/oh2aue/lasermod.htm<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5096278891763426276.post-29451393701401185642015-10-05T14:21:11.307+03:002015-10-05T14:21:11.307+03:00Hello Oona,
It is pretty inspiring and practical ...Hello Oona,<br /><br />It is pretty inspiring and practical project. <br /><br />When I saw your project I just thought about sending digital samples over serial port using couple of optocouplers and diods. Which will provide clear sound output as you can build isolated circuits. You may also send some commands over serial, like volume up and down. I think pcm data will be hard to send but maybe lossy format like ogg is going to be easier. There are already codecs available for teensy and arduino.<br /><br />The only issue is if the frequency of laser and photodiode is fast enough to reach high baud rates.<br /><br />Here is a schematic that I drafted there should be ground and V+ on diode side but I forgot to draw it.<br /><br />Just another pure idea for whom who interested in... :)<br /><br />https://drive.google.com/file/d/0BwBnfbrThVdBNXFDMDBVMVE0Sms/view?usp=sharingMehmet Burhan Tekbaşhttps://www.blogger.com/profile/13397081850303315816noreply@blogger.comtag:blogger.com,1999:blog-5096278891763426276.post-37690566610823873732014-08-17T00:14:48.708+03:002014-08-17T00:14:48.708+03:00When I was in my teens, I built a pair of "wa...When I was in my teens, I built a pair of "walkie talkies" using flashlights, LEDs and pieces of a solar cell. A 4PDT toggle switch handled the transmit/receive operation. A small amplifier (LM386) and a transistor preamp were the heart of the system. Bias the LEDS (4 in parallel) on, feed audio thru a capacitor, and that was it... Amplitude Modulated light! These units had a range of only about 50' but I didn't care... I had proved my concept! (They needed better optics! I was aiming the LED's at the reflector and also using it to crudely focus onto the piece of solar cell. The audio quality was actually quite good! When I fed music into it, the receiver was reproducing the full audio spectrum! :)<br /><br />BTW, did you know that an LED also works "in reverse"? That's right... it creates a tiny voltage when truck by light close to its own frequency! You can use an LED at the receiver end. I confirmed this in my own workshop, not too long ago, so I know it works. :) Happy tinkering! :)Willie...https://www.blogger.com/profile/17925264067870825081noreply@blogger.comtag:blogger.com,1999:blog-5096278891763426276.post-22162045777644520562014-02-03T03:59:17.454+02:002014-02-03T03:59:17.454+02:00A slightly lower tech method of this was done on R...A slightly lower tech method of this was done on Rough Science (series 4, episode 2 "communication"). Laser pointer, old radio and tin can... worked really well over about 100m in full daylight. Hard to find show but typically YT provides http://www.youtube.com/watch?v=e-wrF728ZNo<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5096278891763426276.post-60788920381040359242013-11-26T21:29:53.644+02:002013-11-26T21:29:53.644+02:00Another nice and easy way is having the laser dire...Another nice and easy way is having the laser directly modulated by the tx pin of a µController with a phototransistor at a level shifter connected to a computer's serial port.<br />Of course it needs some blocking from ambient light, placing the receiver in a pringles can and pointing the laser at the diffuse lid did a good job for me.Anonymoushttps://www.blogger.com/profile/14093707238143645325noreply@blogger.comtag:blogger.com,1999:blog-5096278891763426276.post-15416932282164364262013-11-26T05:00:29.151+02:002013-11-26T05:00:29.151+02:00oh you had to do it! the most freaky tune in all o...oh you had to do it! the most freaky tune in all of the known world!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5096278891763426276.post-56920880651219396222013-04-13T19:49:13.655+03:002013-04-13T19:49:13.655+03:00Nice touch using the Lincolnshire Poacher number s...Nice touch using the Lincolnshire Poacher number station as your signal. Anonymoushttps://www.blogger.com/profile/17685885178451464653noreply@blogger.comtag:blogger.com,1999:blog-5096278891763426276.post-32829841908738191632013-02-27T21:06:36.848+02:002013-02-27T21:06:36.848+02:00How cool is that! Thanks a lot for the link.How cool is that! Thanks a lot for the link.Oona Räisänenhttps://www.blogger.com/profile/08764440174916554983noreply@blogger.comtag:blogger.com,1999:blog-5096278891763426276.post-27032535095381334302013-02-27T14:18:55.794+02:002013-02-27T14:18:55.794+02:00I don't know if you are aware of this guys sit...I don't know if you are aware of this guys site, but it has a nice simple AM modulator for laser pointers with common easy to find parts<br />http://www.kolumbus.fi/michael.fletcher/lasermod.htm<br /><br />But your system is very neat and requires zero modifications to the laser source. Anonymousnoreply@blogger.com