• TrainSpotter with Remote Sensor

TrainSpotter with Remote Sensor



"I was having problems with the sensors for my grade crossing flashers... As soon as I replaced the sensors with the ISE sensors, all the problems went away and the crossing signals have worked flawlessly."Jason Klocke.  View Jason’s spectacular CGW layout here.

The TrainSpotter makes detection of locomotives or rolling stock easy and reliable.  Just place the sensor where its invisible light beam will reflect off the object of interest and you're done - no time-consuming or frustrating adjustments!  Based on modern silicon technology, this reflective infrared proximity sensor is tolerant of ambient (background) lighting conditions, be it completely dark or under full lights, with no false triggering.  Combined with a discrete under-track installation, this low-profile sensor solves many of the challenges that plague other optical detector products.

This version comes with the sensor separated from the control board and is ideal for space constrained applications.  The control board also includes terminal blocks for easy connections.


  • Small size (Sensor: 0.25" x 1")
  • No adjustment needed!
  • Simple, discrete under-track installation
  • Variable release time up to 23 seconds (or 23 minutes with Long Delay option)
  • Two opposite polarity, open-collector outputs (40V / 250mA capable)
  • Tolerant of ambient (background) lighting conditions (no false triggering)
  • Terminal blocks for connecting power and outputs
  • Qwiic Connect compatible sensor with 18" cable
  • Powered from 5V to 24V

Typical Applications

  • Activate grade crossing signals
  • Trigger sounds
  • Build an automatic interchange
  • Indicate end-of-track in hidden staging yards
  • Detect block occupancy for signal systems
  • C/MRI track occupancy inputs


The detector is designed to be installed up through the benchwork in a 3/8 inch (10 mm) hole.  Because the sensor itself is so small, only a single hole is required and no complicated drilling jigs are needed.  The sensor can be secured in the hole using a variety of methods such as hot glue or by using a bracket.  An example mounting bracket can be found here.

Electrical Connections

The CKT-IRSENSE-2PC needs 5-24 volts of clean direct current (DC) power to operate.  Two opposite polarity outputs are provided, both of which are “open drain” (otherwise known as “open collector”) and act like a switch to the ground or negative lead.

Logic level outputs can be generated by connecting a resistor to pull up the output to the positive supply.  Other devices, such as LEDs or relays can also be driven directly and the outputs from multiple sensors can be connected in parallel to combine them into one signal.


By default, the release time is programmable from 0.1s to 23s using an external resistor or the onboard potentiometer.  A long-delay option is also available with release times from 6s to 23 minutes - contact us for details.

The activation time is preset to 0.1s.

The sensing distance varies with the reflectivity of the object being sensed, but is typically 1.5".


The complete gEDA design files are available on GitHub.

User Manual

Base Schematic

Sensor Schematic

  • $25.00

  • 3 in stock

Available Options

Related Products



"I was having problems with the sensors for my grade crossing flashers... As soon as I replaced th..


Modular Signal System Cascade ABS Signal Module

Modular Signal System Cascade ABS Signal Module

DiscontinuedThis product has been discontinued.  When existing stock is depleted, we will not b..


Single SPDT Relay Module - 5V Coil

Single SPDT Relay Module - 5V Coil

Single SPDT relay for controlling higher-power loads.  5V coil voltage...


Single SPDT Relay Module - 12V Coil

Single SPDT Relay Module - 12V Coil

Single SPDT relay for controlling higher-power loads.  12V coil voltage...


DCC Block Detector

DCC Block Detector

Isolated, reliable, easy-to-install, single-channel DCC block detector.  Compatible with a wide..


Reflective Infrared Proximity Sensor with Qwiic Connector

Reflective Infrared Proximity Sensor with Qwiic Connector

This device is a simple infrared proximity sensor with a 3.3V compatible I2C interface.  It is ..


News & Application Notes

2018 Optical Detector Roundup

Many of you already know that Iowa Scaled makes both kinds of detectors – an optical detector known as the CKT-IRSENSE, and a current detector known as the CKT-BD1.  When discussing detectors a few months back, Michael and I thought it would be interesting to compare ours with the various other products on the market and figure out who really has the best stuff.   In this installment, we’ll look at six of the most popular optical sensors on the market, comparing and testing them, and try to give you a fair and honest comparison between all your options.  We’re a weird company, and just to prove it again we’re going to say some nice things about other peoples’ products, and some bad things about ours.  Read on…



Write a review

Note: HTML is not translated!
    Bad           Good