Hi All
i am new to this forum and to electronics but not to laser jammers. I have wanted to build one of these for months maybe i can help you help me.
Here is what i know
As described in earlier posts the police gun fire an IR signal at the car and calculates the speed using dopler shift.
The IR signal is a galium arsenide laser diode at 904 nm
The jammer sits in the car grill or number plate and detects the incoming IR signal. This triggers the jammers IR diode to emit on the same frequency thus killing the police signal and setting off an alarm to tell the driver of the speed trap.
The jammer will jam for 5 seconds and then allow the police to get your speed. This should give you enough time to slow down to the legal limit. If the police cannot get your speed at all, they will know you are jamming them.
The jammer will then reset after 60 seconds ready for the next trap.
These Jammers are not illegal in the UK as they have legitimate uses (eg opening garage doors, gates etc.) and it is not illegal to transmit light in the UK.
HOWEVER if you are caught jamming a speed trap you
COULD be charged with 'obstructing a police officer in the course of their duty'
ALTHOUGH most of these speed traps are manned by civilians
Please dont get me wrong im not some crazy guy who wants to drive at 100mph every where. i just feel that if the police are going to become more covert and underhand in the persuit of normal drivers and extra revenue, then normal drivers have to defend their wallets and their licenses: Those people who live in the uk will know what im talking about :x
Any plans or idea anyone has will be appreciated here
post any further questions you may have.
Regards
The Pilgrim
P.S. laser diodes available here
www.lasermate.com/GRImodule.htm