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Vertical range of block detection sensors

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  • Member since
    December 2021
  • 3 posts
Vertical range of block detection sensors
Posted by rbwhale on Monday, December 27, 2021 2:04 PM

Due to space limitations in our new house I am going to build a N scale layout on a door-sized layout made of a slab of two inch pink insulation foam. I want to use block detection senssors to operate a few signals but the current sensing detectors will be on the bottom of the 2 inch thick foam. Will they still operate this far under the track (Kato Unitrack)?

None of what I have read deals with this issue, so I would appreciate any advice you guys could provide.

Thanks

  • Member since
    December 2015
  • From: Shenandoah Valley
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Posted by BigDaddy on Tuesday, December 28, 2021 4:08 PM

Welcome to the forum, your initial posts are delayed in moderation. 

RR_Mel our IR guru needs to comment.  He doesn't limit his placement to underground.  https://tinyurl.com/y6mqj5ow

Oops - Sign you are talking about current sensors.  Since I don't use either, I probably shouldn't comment at all, but that doesn't stop other forum members on other subjects.

My understanding is they work by having the feeder wrapped around a sensor on a board.  They pretty much have to go under the layout so 2" of foam isn't going to be a problem. 

 

Henry

COB Potomac & Northern

Shenandoah Valley

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  • From: lavale, md
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Posted by gregc on Tuesday, December 28, 2021 4:11 PM

rbwhale
current sensing detectors

do you mean electric current and transformer detector, or infared optical sensor?

greg - Philadelphia & Reading / Reading

  • Member since
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  • From: Bakersfield, CA 93308
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Posted by RR_Mel on Tuesday, December 28, 2021 4:44 PM

Welcome

rbwhale

 I want to use block detection senssors to operate a few signals but the current sensing detectors will be on the bottom of the 2 inch thick foam. Will they still operate this far under the track (Kato Unitrack)?

 

Thanks

 

Current sensors are in the block feeder wires not under the track.

I use reflective type optical IR sensors under the track, above the track and across the track where my track is hidden.

 The IR sensor above is a FC-51 sells on eBay for under $1 in bulk.

EDIT:

More info about under the track.

I remove the Sensor and Emitter LED from the FC-51 module and remote them under the track.

I model in HO, easier then N.  I made the drilling jig above to drill the holes between the ties.  For hidden detecrors I simply bend the sensor and emitter wires 90° toward the rolling stock.

 

My Blog Post on my Detectors:

 https://melvineperry.blogspot.com/p/blog-page_49.html

Mel


 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
Turned 84 in July, aging is definitely not for wimps.

  • Member since
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  • From: lavale, md
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Posted by gregc on Wednesday, December 29, 2021 7:38 AM

here's one type of current detector circuit

greg - Philadelphia & Reading / Reading

  • Member since
    May 2004
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Posted by 7j43k on Wednesday, December 29, 2021 10:13 AM

I am using this optical detector:

 

https://www.iascaled.com/store/ModelRailroad/BlockDetection/CKT-IRSENSE

 

It has yet to fail at its task.

 

I believe the top has to be at tie-top height, though experiment might prove otherwise.

There may well be other versions of the concept.  But generally I think you're going to want the critter pretty near the tie-top surface.

Current detectors can be placed "anywhere", so it would seem that's not the OP's question.

 

 

Ed

  • Member since
    February 2002
  • From: Westchester NY
  • 1,747 posts
Posted by retsignalmtr on Friday, December 31, 2021 9:24 PM

I use NCE BD-20 current detector to operate signals and crossing flashers. There is no distance limit, although the feeder length should be only as long as needed in the case of DCC. The track feeder wire passes through the coil on the sensor between the bus and the rail. They do work well to operate relays to control signals. Mine just hang under the layout held in place by the feeder wire or the DC power wire powering the detector. no adjusting the position for operation.

 

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Saturday, January 1, 2022 11:26 AM

Just poke a stiff piece of wire down through the foam where you want the detector, then mark the location, drill up through the foam from the bottom, and glue in a plastic tube.

The IR device can then be 'saboted' as desired and slid up or down as desired for calibration and then clamped at the bottom.

Use two holes and tubes if your emitter and receiver are both below track and you use 'bounce' rather than occlusion to signal occupancy... you can angle the tubes slightly if you want.

  • Member since
    February 2008
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Posted by maxman on Tuesday, January 4, 2022 12:00 AM

RR_Mel

Welcome

 

 
rbwhale

 I want to use block detection senssors to operate a few signals but the current sensing detectors will be on the bottom of the 2 inch thick foam. Will they still operate this far under the track (Kato Unitrack)?

 

Thanks

 

 

 

Current sensors are in the block feeder wires not under the track.

I use reflective type optical IR sensors under the track, above the track and across the track where my track is hidden.

 The IR sensor above is a FC-51 sells on eBay for under $1 in bulk.

EDIT:

More info about under the track.

I remove the Sensor and Emitter LED from the FC-51 module and remote them under the track.

I model in HO, easier then N.  I made the drilling jig above to drill the holes between the ties.  For hidden detecrors I simply bend the sensor and emitter wires 90° toward the rolling stock.

 

My Blog Post on my Detectors:

 https://melvineperry.blogspot.com/p/blog-page_49.html

Mel


 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
Turned 84 in July, aging is definitely not for wimps.

 

Mel:

Several questions:

Is all the stuff shown on your circuit diagram part of the FC-51, or are they additional components that you have to add?

Exactly which FC-51 did you use.  I looked at your link to the FC-51s you had in another post and it took me to a page that had many different items, all apparently related to FC-51.  I don't know what the differences are.

I'm not knowledgeable about a lot of electrical stuff, but know enough to recognize that there seem to be three connection points to the circuit.  Two are ground, and the third is labeled VCC.  I assume that this is the power input.  Is this a three wire line from the power supply (positive, negative, and ground), or a two wire connection (positive, negative, and the other an internal ground)?

What is the power supply requirement?

And finally (I think), what is that 6-sided retangle at the right below the switch and the tubular X thing?

 

Thanks much.

Dick

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Tuesday, January 4, 2022 1:15 AM

The FC-51 is shown as purchased.

Pin 1 is power in, +5 volts.
Pin 2 is ground or -5 vollts.
Pin 3 is activated switched ground.

An LED with a series resistor of 500Ω to 1000Ω
Connected between +5 volts and pin 3 will illuminate upon activation.

I don’t have a clue what the X thing is, in my post?  I don’t have a switch in my post.

Send me your phone number and time to call.  I can walk you through it.

 
Mel



 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
Turned 84 in July, aging is definitely not for wimps.

  • Member since
    February 2008
  • 8,877 posts
Posted by maxman on Tuesday, January 4, 2022 6:50 AM

Mel:  Thanks very much for the reply. 

The switch and the X thing I refer to are shown on the circuit diagram below the picture of the FC-51 included with you post. The X thing is just to the right of a similar thing identified as, I think, 10X.  Possibly they are resistors?

If these are part of the FC-51 I don’t really need to know what they are.

I’ll have to google what an activated switch ground is.

I will try to contact you later this week or next, medical appointments and snow allowing.  Are you able to receive PMs?  I’m in PA, so there is a several hour difference.

Thanks again.

Dick

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Tuesday, January 4, 2022 8:56 AM

My email is in my profile.

Mel


 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
Turned 84 in July, aging is definitely not for wimps.

  • Member since
    February 2008
  • 8,877 posts
Posted by maxman on Tuesday, January 4, 2022 11:53 AM

RR_Mel
My email

Got it, thanks.

Dick

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