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photo cell sensoring

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  • Member since
    February 2010
  • 191 posts
photo cell sensoring
Posted by bnsf0823 on Monday, November 21, 2011 4:17 PM

I have an ho scale layout with a reversing loop at the top and bottom of my layout.  I recently installed tortois switch machines on my turnouts that are controlled by a stationary decoder ds64.  I want to use photo cell sensoring to activate the switches so i don't always have to control the switches on my reverse loops.  what is the best way to make this happen.  The autoreversing units i have are psx-ar.  quesions:

-were is the best place to buy photo cells for between the rails

-what is the best detection device to use for this situation and were can i find it

-i would like to sometime down the road enter into the world of transponding, does anyone have good sights to look at besides digitrax to explain a little more about transponding and how it works.

-will the psx-ar act as a detection unit and connect to the photocells and the switch machines

 

Thanks, scott

 

  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Monday, November 21, 2011 7:36 PM

This doesn't really answer your question, but I use infrared LEDs and detectors pointing across the track instead of photocells between the rails for the simple reason that if you turn off your overhead lighting for any reason a photocell will trigger.  With IR it doesn't matter whether you're running in full sunlight or total darkness.

 

  • Member since
    February 2010
  • 191 posts
Posted by bnsf0823 on Monday, November 21, 2011 7:50 PM

i like that idea what are ways that you use to hide the leds on the sides of the track.  what do you run the led's to?

  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Tuesday, November 22, 2011 10:19 AM

I'm using Fairchild QEE123 Side-Looker Infrared LED (http://www.fairchildsemi.com/ds/QE/QEE122.pdf) and QSE113 Side-Looker Infrared Phototransistors (http://www.fairchildsemi.com/ds/QS/QSE113.pdf) connected to the TDP/NJI ABSMaster Automatic Block Signal Controller and the Logic Rail Technologies Grade Crossing Pro systems.

The LEDs and detectors are mounted in vinyl or brass rectangular tubing such that they are at coupler height.  The tubing is painted to look like a wooden post beside the track and is relatively inconspicuous.

I purchased the LEDs and detectors from Mouser Electronics.

Here's a link to the Logic Rail Technologies IR detector documentation.  My emitters and detectors are mounted as shown in Figure 1b of the Logic Rail document.

http://logicrailtech.com/ATR%20IR%20application%20note.pdf 

If you look closely, you can see a set of the LED/sensor pairs near the block signal mast on my home layout in the first picture at http://members.cox.net/cacole2/cw3_019.htm 

 

  • Member since
    July 2006
  • 8 posts
Posted by wshelhorse on Wednesday, November 23, 2011 7:01 PM

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Scott I’m a little confused.  The psx-ar is a reversing unit that you wire to your tortoise switch machine.  When the unit detects the short it changes phrase and reverses the tortoise switch machine thus lining the switch for the train coming out of the loop.  That’s the whole purpose for the psx-ar unit.

  • Member since
    February 2010
  • 191 posts
Posted by bnsf0823 on Sunday, November 27, 2011 10:40 AM

so what you are saying is that i don't need a photocell to enable my reversing loop to be able to allow the train to go through the reversing loop with out my controlling the turnout entrance of that loop?  all i need to do is hook up the psx-ar to the tortoise switch machine and this will automatically line up the turnout for the train to complete the loop?  Do you have a detailed instructions on how to wire the psx-ar to the tortoise or have a good sight to go to.  and a recommendation on what kind of soider to use and what iron temp iso i don't melt any of my components on the psx-ar/. 

Thanks, scott

  • Member since
    March 2010
  • From: Sherwood Park, Alberta, Canada
  • 252 posts
Posted by CNR378 on Sunday, November 27, 2011 11:02 AM

A manual should have been included with your PSX-AR. If not here is a link

http://dccspecialties.com/products/pdf/man_psxar.pdf

Peter

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