@Mannyrock posted:

What does the operating voltage statement mean please?  Does it mean it can handle up to 24 V before it burns out?   Or maybe it takes 24 V of power input for the sensor to operate?  Or, something else?    I would be powering this with a DC transformer with a throttle control for output.

As to the 5 Amp rating, does this mean that it must have 5 Amps of power before it will operate?  Or, that it can handle up to 5 Amps before it burns out?  Or something else.

Thanks,

Mannyrock

Not a problem.  All questions are good questions.

1. It's designed to operate on 24 VDC.  It may work on somewhat lower voltage, it appears down to 5VDC; below that it may not.  On the other hand it will not survive if you apply much more than 24 VDC.
2. If you supply 24 VDC to it the relay (switch) inside the device will be able to handle a 5 Amp load.  It will pass 5 Amps through it, supplied externally, for an infinite time, but can't handle much more than that without giving up the ghost at some point, perhaps quickly.

Mike

What are you using the PIR sensor for?  Are you expecting burglars on the layout?

Thanks for the excellent answers Mike.  I plan to supply only 12 volts DC or so, so I think I will be OK.

Gunrunner, this sensor may be a more user friendly candidate for operating my layout accessories than the Evans fisheye.  It is already mounted in a cover that has screw holes and can be easily attached to a wooden or plastic post.   The double-strand electric wires going in out look the same as those on a phone charger, so they are flexible, multistrand.  They have plugs on both ends.   I'm not sure what gauge the wires are, but they couldn't be smaller than the 30 ga. wire on the Evans product.      I plan to cut off the plugs, strip the wires, and solder them to 22 gauge transformer power wires, assuming 22 gauge is enough for running  12 DC volts a distance of 5 feet.     

My little transformer has an output range of  0-17 V DC, and max output of 6VA.   

Mannyrock

@Mannyrock posted:

Gunrunner, this sensor may be a more user friendly candidate for operating my layout accessories than the Evans fisheye.

I think you totally missed my point!  This sensor is not going to react to passing trains!  It's a thermal sensor that looks for a temperature difference between an object in motion and the surrounding background.  It's specifically designed to detect warm bodies, i.e. people.  Note the sensing range is 15 feet!

Gunrunner,

Thanks, I understand what you are saying.  Yet, three months ago, when I was first investigating the Evans Design sensor, many people on this Boad examined the online pictures and descriptions of it on the Evans website and were certain that it operated on temperature differences as well.    And yet, the thing works fine when my train passes by, as long it is situated not more than 1.5 to 2 inches from the side of the track.

You may want to check it out on the Evans website, and see if you agree as to it being a temperature sensor.  The fisheye geodesic lens on the Evans sensor looks identical to the fisheye geodesic lens on the different sensor I am considering, and in fact, it looks like virtually all of the lenses on the inexpensive motion sensors sold on Amazon.

Sorry I don't know much more about this issue.

Thanks,

Mannyrock

If it works for you, that's all that counts I guess.  I personally don't want a PIR sensor with a 15 foot range controlling signals, every time I walk past it, it's likely to trigger. There are lots of better ways to trigger signals, one of many being the Untrasonic sensor.

HC-SR04 ultrasonic sensor for outdoor layout block detection

This sensor can even be adjusted so that with two adjacent tracks, it'll only trigger on the closest one!

Wow Gunrunner, thanks for all of those recommendations.  If I can ever get these sensor things worked out, I plan to have 4 or 5 of them on my layout.

One interesting thing I found about the Evans sensor, was that if I mounted it, and glued a 1.5 inch section of pvc pipe over top of the sensor eye, so that the eye was "looking" down through a narrow tunnel, and then I positioned the sensor/pipe two inches high next to the track, but then tiled the sensor/pipe so that it was pointed at a downward angle, such that it was pointing at a spot on the layout table ten inches on the other side of the track, then the sensor would act as a "focused beam" and not trigger when I walked around the table or worked on the table, so long as I didn't interrupt that  beam.  Waiving my hand in that beam would, however, definitely trigger the sensor.

I sure learned a lot from that $8.00 sensor, but it has eaten up a great deal of time, with no successful finished project so far.

Thanks again,

Mannyrock

Just a strange follow-up thought.  Evans says that the Evans sensors are made to operate trackside accessories.  It would be curious to me if the switch only operated when someone (warm) passed by the sensor, as opposed to when a motorized unit passed by it.  But then again, this is all Greek to me.

"I am just a simple unfrozen Caveman lawyer.  I am frightened and confused by your strange and mysterious ways." :-)