Optical Sensor needed

[Papa-LF]

Adding another item to my display, and need an optical sensor that will close a relay. I basically need a "Through the beam" sensor. Found a number of expensive devices on-line, but was hoping not to spend $100 on it. It needs a seperation of about 4 to 6 inches, and the type with a reflector will work just fine.

Any ideas?

[Guest guest]

what about the safety sensor devices for garage door openers? Might take a little hacking to make it work, but would assume you would get the "beam broken" signal you need, and then interface to a relay.

I see replacement units online for under 40 bucks...

[Steven]

Garage door sensors use a 2-wire circuit, through which both power and signal pass. You'll have to do some electronic detective work to figure out how to separate the power from the 'beam interrupted' signal.

[MikeH]

Papa-LF wrote:

Adding another item to my display, and need an optical sensor that will close a relay. I basically need a "Through the beam" sensor. Found a number of expensive devices on-line, but was hoping not to spend $100 on it. It needs a seperation of about 4 to 6 inches, and the type with a reflector will work just fine.

Any ideas?

See if this will work for you.

http://booityourself.blogspot.com/2010/09/foot-trip-sensor-for-halloween-scare.html

[Steve Constantino]

Try this.

http://www.automationdirect.com/adc/Shopping/Catalog/Sensors_-z-_Encoders/Photoelectric_Sensors/High_Performance_AC-z-DC_(Cutler-Hammer_Enhanced_50_Series)/Polarized_Retroreflective_(1451E_Model)/1451E-6513



I get stuff from here all the time.

Steve

[Greg Young]

If you are planning to use this sensor outside, under varying conditions, save yourself a lot of time and grief from false sensings by using PIRs (passive infra red sensors). I have used these to trigger aspects of my display since the early 1980's. They work much more reliably than photocells/interrupted beam applications..
These can be had for under $20.
Greg

[Papa-LF]

Greg Young wrote:

If you are planning to use this sensor outside, under varying conditions, save yourself a lot of time and grief from false sensings by using PIRs (passive infra red sensors). I have used these to trigger aspects of my display since the early 1980's. They work much more reliably than photocells/interrupted beam applications..
These can be had for under $20.
Greg

Greg, wouldn't be using this to detect movement or motion - would use it to detect something passing through a confined area inside a device. Don't think that would work for this application, but I am very open to you proving me wrong if you have another idea.

Lowell

[alaskastudio]

I use these all of the time in photography to trigger my flash head.
http://hiviz.com/kits/instructions/spg-du-manual2.htm

I personally use the SPG2 kits as it has the holder included for the IR LEDs. The SPG1 kit has separate IR LEDs that you can build your own holder for. Everything runs off of 1 9v battery, and the above kit also includes a timer to delay in milli-seconds to help fine tune the trigger.

Here is there price page, and if you don't mind building it (directions are included) they are about $20.

http://hiviz.com/kits/guide.htm

I hope that will work for you. They also have sound activated triggers too.

[Greg Young]

Papa-LF wrote:

Greg Young wrote:

If you are planning to use this sensor outside, under varying conditions, save yourself a lot of time and grief from false sensings by using PIRs (passive infra red sensors). I have used these to trigger aspects of my display since the early 1980's. They work much more reliably than photocells/interrupted beam applications..
These can be had for under $20.
Greg

Greg, wouldn't be using this to detect movement or motion - would use it to detect something passing through a confined area inside a device. Don't think that would work for this application, but I am very open to you proving me wrong if you have another idea.

Lowell

Hi Lowell:

I skimmed too quickly, and missed the 6 inch part! I was thinking you were talking about external triggers.....

For inside of a device you can get a small IR emitter and sensor that will do the job very nicely! (I've used them in small areas.. in the old days to detect cars on HO rail yards that were hidden from view).

Nice to hear from ya'!

Greg

[Papa-LF]

Jeff Millard wrote:

Lowell,

I tried to reply earlier this morning but the I got that dreaded "Bad Requests...Error 400" and lost the post. An engineer I work with suggested magnets and reed switches to do what you're describing. Like those used in alarm systems and door chimes. They're pretty accurate, and simple. You know the Mythbuster Jaime creedo... Keep it simple.

Jeff

Jeff, I think that Error 400 has fried your knogen - looking at yur avatar - yep true story ! LOL

Actually, simple is good, but in this case magnets and reed switches wouldn't work - ( too bad I have a bundle in my junk box in the garage - used to install security junk - er aaa stuff)

Didn't want to reveal too much of this project, but what the heck - the item being detected to trigger an event is $$ falling down a slot in the new donation box - will then trigger my old fireworks ball and a Thank You sign on my roof. I picked up a CTB16D (stand alone) from Robin that will receive the signal from the trigger and start this piece of the show... http://www.papasplace.us/video/08LOR/July4_Pledge.wmv

I figure it this way, since I stepped up my fund raising for Cystic Fibrosis this year, if I make giving into the donation box fun it will bring in more kids wanting to light the lights, thus more money for CF for the kids so they can breath, and hopefully find a cure so they can live longer..

With that thought in mind, I will purchase a good photo sensor setup so it works right all season. Its personal. Someone I cared about very much died from this disease. A guys gotta do what a guys gotta do...
http://www.automationdirect.com/static/specs/perectfg.pdf

[zman]

Great idea Lowell, we may have to talk about this one a bit more on the side. I like the idea of drawing attention to the donations. It will no doubt do what you need it to do. Now I need to see how I can rig something up on my box.