Dependable, Nice-looking Detector
These track occupancy detectors work very well to activate any sort of trackside signal or other accessory. They are relays that make and break current flow, and the current is totally independent of the track voltage so a transformer can be set to provide optimal voltage depending on the needs of the particular accessory.
The operator simply attaches a power and a ground wire from an AC transformer to the + and – wire screw connections on the detector. Then to route power to an accessory as a train passes, attach a wire from the NO (Normally Open) screw connection on the detector to the accessory and, of course, run a ground wire to the accessory as well. That ground wire can be attached to the COM (Common) screw connection on the detector or just splice it in to the ground wire coming from the transformer. When a train passes, the Normally Open switch inside the detector closes, sending power to the accessory.
Now, let's say that we want something to turn off when a train passes but be on at other times. Run a power wire from the NC (Normally Closed) screw connector on the detector to the accessory. When a train passes, that internal detector switch will open, breaking the current flow to the accessory.
If using an accessory such as a Post War Era-style semaphore, we need the light to be on at all times but we want the blade to operate only when a train is detected. This can be done, but I confess that I had to experiment for a while but finally figured out all the connections—and you can, too! Then, of course, I had to add a dwarf signal to go from red to green in conjunction with the semaphore (the railroad had added a new signal but had left the old one still operating). This necessitated some additional experimentation but now works great with the single ITAD detector.
The MTH 45-1028 detector is light weight with a plastic case but has provisions for attaching it to the layout surface with two screws. As other reviews note, it has adjustments to increase or decrease the sensitivity with which it senses the presence of a passing train and also the length of time it will continue to operate after the train has passed by. It is independent of the track both physically and electrically so it works with every brand of track.
As with all IR detectors, consistent operation is somewhat dependent upon room lighting and upon reflectivity of the passing train. However, I have used IR detectors from other O gauge train manufacturers, and my experience is that the MTH 45-1028 detector is the most reliable of all. In fact, I am replacing IR detectors from other brands with these MTH units.
As has been noted by other reviewers, if there is a weakness in this product, it is the lack of comprehensive instructions. I drew simple wiring diagrams for the accessories to be controlled by the detector, labeling each wire as to power and ground, and indicating which needed to connect to the NO and the NC terminals on the detector made the wiring go much easier. Remember: model railroading is FUN (even the wiring)!
One last thought: If using these ITADs to operate crossing signals, you may want two of them if your layout has trains operating in both directions, placing one “upstream” and one “downstream,” of the crossing so the signal will activate in time regardless of the direction of the train. And, yes, two or even more of the ITADs can be wired together in parallel, though again there are no instructions for doing so, but that's a straight forward wiring situation. Just be sure to keep your power and ground wires identified and separate!
Verified purchase: YesCondition: New