BASIC ELECTRONIC Circuits for lasercom


1) Simplest RX/TX I know of.. All RadioShack Parts. Add your own laser
pointer. A real working system, will go >1 mile with NO lenses.
http://www.qsl.net/wb9ajz/laser/data/cheepo.txt

Outside view of the MCW TX system
Inside view of the modulator
Circuit diagram of modulator
Some laser pointers, pigtails added to a couple for example

2) Next best easy way..
this company sells 2 kits... (they are not on the website)

One is a "laser simulator" (a 555 with a bright LED) easily changed to
drive a pointer instead. And.. Change timing cap to make it 800hz
instead of 1hz.
about $5

Other is a "laser target" (a IR PIN with audio amp) in the cct the audio
amp drives some LED's that light when you hit it.  Instead you hook up a
speaker and sound comes out! from above laser simulator.
about $8

http://www.halted.com



Essentially the key items to use are:

0) none of these are gonna set any records.. but with a 8x10 fresnel you
will make 20 miles or more with a 2mW laser pointer.

1) TX: 555 timer circuit in astable mode (oscillator) interrupted with
pin 5.

2) RX: either of 2 ccts:  a phototransistor (cheepo.txt) or a PIN
feeding into an audio amp. (you can buy pocket audio amp at RS for $12)



Examples of a PIN diode receiver:
Outside view
Inside view


Examples of a Burr-Brown OPT210 receiver
OPT210 mounted in foil, wrapped by electrical tape, and mounted on the back of a lens cover.
This facilitates use on telescope or on binocular optics.

Examples of a IR PMT
View of a side on PMT with integral voltage generator and divider
The PMT is mounted on an angle backet to allow it to be put into a lens system.
See section on basic lenses!


A complete professional voice IR communication system!!!! for only $19
A laser diode can be used to replace the IR diodes!