Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!bionet!ames!amdahl!kelly From: kelly@uts.amdahl.com (Kelly Goen) Newsgroups: sci.electronics Subject: Re: Bad News- Lasers replace Radar guns Message-ID: Date: 20 Jan 90 04:38:41 GMT References: <7263@lindy.Stanford.EDU> <349@egrunix.UUCP> <4236@rsmas.miami.edu> <353@egrunix.UUCP> <4264@rsmas.miami.edu> Reply-To: kelly@amdahl.uts.amdahl.com (Kelly Goen) Distribution: na,global Organization: Amdahl Corporation, Sunnyvale CA Lines: 15 In article <4264@rsmas.miami.edu> EAKIN@rsmas.miami.edu writes: >In article <353@egrunix.UUCP>, besler@egrunix.UUCP (Brent Besler) writes: >> >> In general the speedometer in the cop car may be off a couple of MPH, and that >> can make big a big difference with regard to fines, etc. Radar gun aren't >> wired into a cops speedometer. They use a separate radar beam to determine >> the speed of the cop car relative to the ground. well you were only half right the early moving RADARS used a magnet and a hall effect sensor on one of the wheels for a speed pickup... I know because I used (15 years ago) to install these on OK HPD vehicles for a few short months.....the current tech I cant answer with certainty on but I suspect it is still the same....GUNPLEXERS cost 100 times as much as a hall effect sensor and the associated timing electronics... cheers kelly