Good idea, Joerg. Where do I get onesie-twosie IR sensors that will trigger
at 3 meters or better?

Jim



"Joerg" wrote in message
om...
Hello Jim,

Since you said this is a road with very little traffic can't you just rig
up two IR sensing paths?

Hello Jim,

Good idea, Joerg. Where do I get onesie-twosie IR sensors that will trigger
at 3 meters or better?


No idea but one source might be remote controls and the corresponding
receiver diode in the set or from a stereo. I bet that Radio Shack will
have something if there still is one in your area (our became a cell
phone store). You'd need a crude reflector on the other side, piece of
metal or white board.

Another source might be if someone replaces their garage door opener.
They usually come complete with the child protect barrier and most
people will throw out the old one.

Thing is, you need at least two sets. The LEDs could be running all the
time and you just have to sense the receive elements.

There is yet one more method: Two coils next to the road, each with
oscillator. On fence posts, wherever. A car will de-tune it or, if set
on the edge of the stable feedback range, would stop the oscillator
momentarily. In contrast to the IR method and the Doppler method this
can be made pretty weather proof from cheap wire.

Regards, Joerg

http://www.analogconsultants.com

Joerg wrote:

Hello Jim,

Good idea, Joerg. Where do I get onesie-twosie IR sensors that will
trigger at 3 meters or better?


No idea but one source might be remote controls and the corresponding
receiver diode in the set or from a stereo. I bet that Radio Shack will
have something if there still is one in your area (our became a cell
phone store). You'd need a crude reflector on the other side, piece of
metal or white board.

Another source might be if someone replaces their garage door opener.
They usually come complete with the child protect barrier and most
people will throw out the old one.

Thing is, you need at least two sets. The LEDs could be running all the
time and you just have to sense the receive elements.

There is yet one more method: Two coils next to the road, each with
oscillator. On fence posts, wherever. A car will de-tune it or, if set
on the edge of the stable feedback range, would stop the oscillator
momentarily. In contrast to the IR method and the Doppler method this
can be made pretty weather proof from cheap wire.

Regards, Joerg

http://www.analogconsultants.com
Actually inductive loop detectors (buried or not) require fairly good wire
to last more than a year. Plus you have to provide a roadside cabinet and
detection electronics, and power therefore. of course you can space them
carefully and detect speed that way also.
--
JosephKK

On Sun, 08 Jan 2006 20:00:17 -0800, RST Engineering wrote:

Good idea, Joerg. Where do I get onesie-twosie IR sensors that will trigger
at 3 meters or better?


Look at garage door opener safety electric eye thingies. ;-)

Cheers!
Rich

Jim



"Joerg" wrote in message
om...
Hello Jim,

Since you said this is a road with very little traffic can't you just rig
up two IR sensing paths?

...try Philips . they manufactured once a module working in the X band
for security detectots, doors openers and suchlike. if I remember
correctly iwas named CL-8XXX.

On Sat, 07 Jan 2006 11:28:12 -0800, RST Engineering wrote:

Back in the '60s and early '70s I did some work with Impatt and Gunn diodes,
building a little self-detecting doppler for speed sensing. However, 35
years have passed and my notebooks for that stuff are somewhere in a dusty
archive along with my venerable sliderule.

Is there a cheap source for onesies-twosies of a radar front-end that will
give me doppler audio as a function of a large metal object's speed at a
range of 20 meters or so? I don't need to go into production on this thing,
just build one. A surplus source would be ideal.

It seems that the little kids on our rural country lane have all become
teenagers at once and are trying to outdo the others in how fast they can
drive daddy's car up and down the lane. We've lost one dog this week and
unless I can put up some sort of a siren that goes off when they exceed some
agreed upon limit, the carnage will continue.

Just call your local cop shop, and find out where they get their radar
guns - if these kids are posing a threat to life and limb, the cops might
come out and do it for you.

Good Luck!
Rich

On Sat, 07 Jan 2006 11:28:12 -0800, RST Engineering wrote:

Back in the '60s and early '70s I did some work with Impatt and Gunn diodes,
building a little self-detecting doppler for speed sensing. However, 35
years have passed and my notebooks for that stuff are somewhere in a dusty
archive along with my venerable sliderule.

Is there a cheap source for onesies-twosies of a radar front-end that will
give me doppler audio as a function of a large metal object's speed at a
range of 20 meters or so? I don't need to go into production on this thing,
just build one. A surplus source would be ideal.

It seems that the little kids on our rural country lane have all become
teenagers at once and are trying to outdo the others in how fast they can
drive daddy's car up and down the lane. We've lost one dog this week and
unless I can put up some sort of a siren that goes off when they exceed some
agreed upon limit, the carnage will continue.

Get a piece of baling wire, and tie two garbage cans together, one on
either side of the alleyway, with the wire about 18" (1/2M) off the ground.

That should slow the little *******s down! :-

Good Luck!
Rich

"Rich Grise, but drunk" wrote in message
news
Get a piece of baling wire, and tie two garbage cans together, one on
either side of the alleyway, with the wire about 18" (1/2M) off the
ground.

That should slow the little *******s down! :-

Yeah, it would. You should see what pranks like that do to motorcyclists.

On Wed, 11 Jan 2006 16:30:17 +0000, Mike Young wrote:

"Rich Grise, but drunk" wrote in message
news
Get a piece of baling wire, and tie two garbage cans together, one on
either side of the alleyway, with the wire about 18" (1/2M) off the
ground.

That should slow the little *******s down! :-

Yeah, it would. You should see what pranks like that do to motorcyclists.

But, on your motorcycle, you wouldn't go racing down an alley like that.
At least I know _I_ wouldn't! I drive kinda like this guy:
http://www.abiengr.com/~sysop/images/Safe-Car.gif ;-)

Cheers!
Rich

"Rich Grise" wrote in message
news
On Wed, 11 Jan 2006 16:30:17 +0000, Mike Young wrote:

"Rich Grise, but drunk" wrote in message
news
Get a piece of baling wire, and tie two garbage cans together, one on
either side of the alleyway, with the wire about 18" (1/2M) off the
ground.

That should slow the little *******s down! :-

Yeah, it would. You should see what pranks like that do to motorcyclists.

But, on your motorcycle, you wouldn't go racing down an alley like that.
At least I know _I_ wouldn't! I drive kinda like this guy:
http://www.abiengr.com/~sysop/images/Safe-Car.gif ;-)

Even if I did, the prescribed penalties amount to a few dollars, not skin
grafts, limbs, and brain tissue. Fun is fun, and talk is talk. But let's not
forget that life isn't a cartoon peopled with faceless stunt doubles.