peter s asked:
need t o connect a laser trip wire to send a signal to a transmitter then that signal to send to a reciever over 200 mtrs which will then sound a alarm
need t o connect a laser trip wire to send a signal to a transmitter then that signal to send to a reciever over 200 mtrs which will then sound a alarm
go to radio shack you will need a relay that picks up the lazer light and switches the radio frequrncy on to the transmitter
If the range were only 150m or less you would be able to do it with DECT (cordless phone) modules. However for 200m the cheapest and dirtiest method would to be to buy two mobiles phones. One set to ring the other at the laser end when the laser trips and pushes the call button and the other remote with the ringer speaker attached to the alarm circuitry. To do it any other way over this range would probably require expensive radio gear and perhaps a licence.