TrainSpotter
"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.
Features
- Small size (0.25" x 2.25")
- Simple, discrete under-track installation
- No adjustment needed!
- Release time of zero or 5 seconds (solder jumper), custom times available
- Two opposite polarity, open-collector outputs (40V / 250mA capable)
- Tolerant of ambient (background) lighting conditions - no false triggering
- 24" pre-stripped wire leads attached to the sensor
- Powered from 5V to 24VDC
- Optional mounting bracket available
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
Installation
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 needs 5 to 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.
Specifications
2.25"(L) x 0.25"(W) x 0.25"(H)
By default, the release time is zero, but can be set to 5 seconds by
shorting two pads (JP1) on the back of board. Custom release times,
including up to 23 minutes are also available - contact us for details.
The sensing distance varies with the reflectivity of the object being sensed, but is typically 1.5".
Documents
The complete gEDA design files are available on GitHub.
-
$19.00
- 6 or more $18.00
- 12 or more $17.00
- 24 or more $16.00
- 8 in stock
Available Options

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News & Application Notes
Using TrainSpotters and SoundBytes With Crossing Modules
One of the questions we get somewhat frequently is how to use the TrainSpotter infrared detectors and SoundBytes crossing bells with other vendors’ grade crossing modules. After all, we offer the most reliable IR detection for the model railroads in our TrainSpotter line, along with the widest variety of prototype bells in our SoundBytes. Who wouldn’t want to upgrade their grade crossings?
Today I’ve put together a guide for three of the more popular crossing control modules and show what can be done with each. Specifically, we’re going to look at Logic Rail’s Grade Crossing Pro/2, Azatrax’s MRX3, and Dwarvin’s Lamplighter Flasher, along with a cheap popular Chinese flasher module from eBay.

Dwarvin’s Railroad Crossing
If you’re in the market for a simple railroad crossing system, take a look at Dwarvin’s Lamplighter Flasher and Integrated Railroad Crossing. Dwarvin’s easy-to-use, fiber-based Lamplighter – which comes with our TrainSpotter detectors and SoundBytes bell module – makes a painless way to add crossing signals to your layout. Give it a look!
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…
Automatic Interchange
Iowa Scaled Engineering products were recently mentioned in one of the Model Railroader Video Plus episodes, featuring Tony Koester’s Nickel Plate Road.
In this video (subscribers only) you’ll see our CKT-IRSENSE and ACC-RELAY1 products used in an automatic interchange. Each time a cut of cars is picked up, a new cut of cars is automatically pushed forward. For those wanting more details, Tony has written an article about automated interchanges that appears in the December 2016 issue of Model Railroader.
DCC Auto-Reverser
We were recently asked to build a module that could automatically reverse a locomotive between two end points for use on a small point-to-point switching layout. The idea was to provide a means for continuous running of a train while working on the layout or to break in new locomotives without user intervention. The end result is described here, with instructions for building your own. At the current time, this is a mostly a DIY project, but if you want help building one, please let us know.
Auxiliary Power from a DCC Bus
While DCC is primarily meant to power and communicate with the trains on the tracks, there are circumstances where having some auxiliary power available would be nice without having to run an extra set of wires. Maybe powering a remote turnout, an IR sensor, some animation or building lighting, or a fast clock secondary display?
Adventures in Lighting: Part 2
Addressing some of the problems of the design in Part 1, a new lighting system for the pantry has been installed.
Simulate a Spring Switch
Spring switches are used by some prototype railroads to save the crew from having to re-align the switch points after passing through the switch. The switch is sprung in one direction (typically the mainline), allowing any train to pass through the switch from the frog end without manually aligning the points. When entering the mainline from a siding, this allows the train to continue on its way without having to realign the points to the main – the spring action takes care of this automatically. Modeling this unique feature can be easily accomplished with an IR sensor and switch machine.Read More...
Infrared Proximity Sensor
The CKT-IRSENSE is an inexpensive reflective infrared proximity sensor, designed primarily for model railroad use, utilizing the latest in proximity sensor technology. It can be used to trigger a variety of sound and visual effects as well as provide track occupancy status. The sensor’s small size (0.25″ x 2.25″) makes installation simple with only a single 3/8″ hole required. The technology used in the CKT-IRSENSE makes it highly tolerant of background lighting conditions, thus requiring no user adjustments.