LOC3 Dual Laser Occupancy Detector


The LOC3 provides provides occupancy detection for two independent staging yard throats, solving the problem of knowing when trains have entered or cleared this vital track. Check out these features!

A laser beams light onto mirrors, reflecting several times across a yard throat and into a photocell. The laser and mirrors can be positioned to provide complete coverage of the throat.

Important Notice – User Manual

The 44-page, fully-illustrated user manual is available online only. A printed copy is not included with the LOC3. Please download it here. (3.8MB PDF, right-click, save...)

The manual contains complete instructions for assembling the LOC3 kit and checking-out the completed unit. I recommend looking it over as you consider whether to order the LOC3 as a kit or fully-assembled.

What to Order

One LOC3 can monitor one or two yard throats. Order the LOC3 as a kit that you solder together, or already assembled and tested.

You need one laser module for each yard throat. There is no requirement to buy the laser modules from me if you have another source, but if you do order them here, you are assured that they work with the LOC3.

You can order laser modules separately (or as separate items on a LOC3 order), but you'll save money if you order a LOC3 with lasers. See the details here or here.

Order the items you want by clicking the buttons below. To buy more than one of an item, change the quantity in the shopping cart.


When done adding the items you want, go to your shipping cart and click the Checkout button to pay with a credit card, or Checkout With PayPal to pay through your PayPal account.

If using a credit card, you'll see a screen like this. Make sure the Credit Card option is selected, then enter your billing and shipping information, and click the Review and Continue button.

When done checking out, you will see a screen confirming the transaction, and later will receive an email.

LOC3 kit – $50.00
LOC3 kit with two lasers – $75.00

The kit includes the circuit board and all electronics parts.

Note: This photo shows only a representative assortment of parts, not everything that comes in the kit.

Get a $5.00 discount and save postage by ordering the LOC3 kit with two laser modules, or you may order them separately.

LOC3 Kit Choice

Assembly instructions are in the user manual. This manual also contains valuable information on how the LOC3 works, and how to install it on your railroad.

LOC3 assembled and tested – $80.00
Assembled LOC3 with two lasers – $105.00

The LOC3 is completely assembled and tested, ready to install on your railroad.

Get a $5.00 discount and save postage by ordering the assembled LOC3 with two laser modules, or you may order them separately.

Important! Please read this Output Type Selection Guide before ordering an assembled LOC3. Then select Isolated outputs or Direct outputs in the drop-down list below.

Assembled LOC3 Choice
Output Type

Even though the LOC3 is assembled, you'll still need the user manual to learn how it operates and how to install it on your railroad.

Laser module – $15.00

A laser module that is tested and verified to work with the LOC3.

Note: This photo shows a typical laser module. Size and style may vary slightly.

Red laser modules are fairly standard. If you buy your own elsewhere, they probably will work with the LOC3. But you know they will work if you order them here.

Updated September 7, 2016