Model Train Technology MTT PRECISION DETECTOR User manual

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MTT PRECISION DETECTOR™ -Trackside
1mm precision up to 150mm
OPERATIONS MANUAL
Version 4.2a
Works with Z, N, HO and O Scale

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The Model Train Technology™ PRECISION DETECTOR™ –
Trackside is designed to provide an adjustable, multifaceted
and precise way to detect trains on one or more parallel tracks
with the least amount of work to install and operate. At last,
there is no need to adjust or calibrate for changing or difficult
light conditions. The detector is housed inside an 3D printed
electrical box that is mounted from the top of the layout. We
think this is easier than banging around under the layout to
install brackets and drill holes in the track. It’s also more
prototypical because the real track detection of modern
railroad IS housed inside electrical boxes along the trackside.
We provide two types of base mounts, one with holes for
screws or glue, or a minimally sized base that matches the
footprint of the electrical box cover. The PRECISION
DETECTOR™ sensor board slides into the base bracket and then
the box top slides over that.
After we had our share of frustration with IR (infrared)
detectors that are susceptible to ambient light, particularly
florescent, some LEDs and mercury bulbs found at large train
shows, we searched for a smaller, faster, more precise
technology that would also be impervious to poor light
conditions. The sensor we chose, along with our software, will
detect the location of a train car anywhere within a 150mm

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(5.5”) range with 1mm precision without regard to lighting
conditions.
This means you can put the sensor near the track, or you can
hide it away in a nearby building or in the side of a hill. You can
also use the PRECISION DETECTOR™ to alert when a train has
reached the endpoint of track inside a hidden yard. In other
words, aimed down the track from the endpoint, not across it.
In this example the detector will only “see” the train on the
track its’ aim down – and not the adjacent track.
Summary of Features:
• Long, precise sensor range (1mm up to 150mm)
• No more adjusting for varying light conditions.
• Adjustable detect ranges (N & HO and O gauge)
• Auto-calibration mode for precise range setting
• Detect one parallel track and ignore the others
• Adjustable time-out (0-60 seconds)
• Reversable Signal output (INVERT)
• Two mounting options
• Electrical box integrated design
• Includes a 2mm screwdriver.

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HO PRECISION DETECTOR™ sensor board
Yellow Signal Wire
(OPEN DRAIN TO GND)
12VDC
SELECT button
SWITCHES
Timeout Adjust
Indicator LED
Range Adjust

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N Scale PRECISION DETECTOR™ sensor board
Range Adjust
Indicator LED
Light
Timeout Adjust
SELECT button
12VDC
Yellow Signal Wire
(OPEN DRAIN TO GND)

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The board can be powered with a 12VDC supply which is what
the MTT Power Module outputs. To make sure all the
detection works properly we designed a low-cost Power Center
Module that comes with a power supply.
To operate properly the Signal Controller and the Precision
Detector must be connected to the same power source.
A single push button has replaced the DIP switch. This makes it
easier to set the configuration settings and you don’t need
glasses! Simply press the SELECT button according to this chart:
The detector can be set to detect an adjustable Wide Range
from 5mm up to 150mm. Anything within the range you set
beginning at 5mm - will trigger the detector.

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The second mode allows you to select a narrow sub-range
anywhere within the 5-150mm range. If you select N Scale the
detection range will be 10m WIDE and that 10mm range can be
“placed” anywhere inside the 5 to 150mm range. Anything
closer or further will not be detected.
Detection Range Width:
N Scale 10mm
HO/O/S scale 15mm
All you do is push the SELECT button to fit your scale and adjust
the location of the sensor to meet your specific needs.
In addition, there is a second trim potentiometer (trim pot) that
allows you adjust how long the trigger stays “tripped” after the
detector is clear. We provide a 2mm screwdriver for adjusting
this. (I can’t tell you how many times I needed a small
screwdriver for this kind of thing and could not find it and
didn’t want to buy another jeweler’s kit.) If you buy a lot of
detectors, you can return the extra screwdrivers. We will reuse
them.
The default setting with the trim pot adjusted all the way to the
left (counterclockwise) is under 1 second. With the dial

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adjusted all the way to the right (clockwise) the timeout period
is either 30 seconds or 60 seconds depending on the timeout
option selected via the pushbutton.
If you are using the PRECISION DETECTOR™ with our MTT
Signal Controller you will most likely want to leave the setting
to 1 second and let the Signal Controller manage the timing. If
you are using our Sound Module, then use the PRECISION
DETECTOR™ timing to adjust when to stop a sound after the
train has passed. An example would be a crossing bell sound.
With our Fiber Lighting Controller and a gate crossing use the
PRECISION DETECTOR™ to set the timeout so the lights and
sound stop at the same time.
The PRECISION DETECTOR™ provides a DIGITAL signal output
(LOW) which is the kind used by many model railroad electronic
controls that you would normally hook up such as sound
modules, Light Controllers (like our Fiber and LED Controllers)
and Block Signal Controllers. This detector can be configured
to switch a relay that has a digital input option, but it cannot
power or switch the relay itself. (see the example at the end on
how to connect a relay)
Once installed on the layout, the supplied electrical box cover is
designed to protect and hide the electronics. We recommend

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using Gem-Tack® glue to fasten the mounting plate to the
layout surface. The advantage of using this particular white glue
is that you can remove it if you need to. Don’t use “super
glue".
On the board is a blue indicator LED. This will flash four times
when power is first turned on and thereafter will light when the
detector is triggered. (INVERT mode will have the light ON
when not triggered and OFF when triggered)
The Precision Detector software has been updated to include
a new feature called Auto Calibrate. This make setting the
exact distance for detection to a rail car extremely simple.
STEPS:
1. To activate the saved calibration, the trim pot for ranging
must be set to zero. Turn the trim pot with the
screwdriver all the way to the left (counterclockwise).
The trim pot for the HO sensor is on the left and for N
scale it is the lower of the two.
2. If this is the first time to use calibration, the saved setting
may also be zero.