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Speed Threshold Sensor Module

This is the STS, a circuit module that indicates whether a train's speed is above or below a configured threshold.

Description

A self-contained circuit board with two pulse inputs from train detection switches, two pulse outputs, and an onboard remote trigger that serves as an adjustable timer. The combination of the distance between the detection switches and the timer is used to define a threshold train speed. When a train reaches the second detection switch a pulse is emitted from either output depending on whether its speed is above or below the threshold.

The on/off switch on the module must be in the off position when not measuring a train.

I do not require attribution if you incorporate this module into a published layout, but if you do so please post a link in the comments so I can see it in action.

Setup

Train detection switches should be set to Start only and can be connected wirelessly via the white onboard Remote triggers.

Output can be transmitted wirelessly by deleting the wires to the output terminals and setting passwords for the AND gate outputs.

If traffic is bi-directional opposing traffic will generate false outputs. False outputs can be prevented by adding an on/off train detection switch and AND gate as shown. The on/off switch must be connected to the AND gate by wire, but wireless connection can still be used for the other detection switches and also between the AND gate's output and the onboard trigger.

The Trigger delay parameter of the orange Remote trigger can be thought of as a timer. You can set the timer to a fixed value and move the train detection switches to match the threshold speed, keep the switch positions fixed and adjust the timer, or try to adjust both simultaneously.

A rough formula for detection switch spacing (centre-to-centre), in cm as measured by smokestream888's Precision Ruler - 1 Metre mod:

Metric: spacing = (speed in km/h) x (timer value in seconds) / 3
Imperial: spacing = (speed in mph) x (timer value in seconds) / 2

E.g. for a threshold speed of 45km/h and with a timer value of 1s, a spacing of 15cm will get you close to target.

Flipping those around we also have:

Metric: timer = spacing x 3 / (speed in km/h)
Imperial: timer = spacing x 2 / (speed in mph)

See the attached images for a table of example spacing and timer settings for splitting the default notch speeds.

Multiple thresholds

Multiple modules can be stacked to test against multiple thresholds simultaneously, and can all share the same detection switches using different timer values as shown.

How to copy the module to your layout

Use the Bulk move tool (Room.6). Before selecting objects you will need to make the Details (circuitry), Terrain (baseboard), and Room (labels) layers editable. You should see a "Props selected" count of at least 35.

Click Copy and then Done in the tool dialog. Close this layout and open the destination layout. Grab and position another Bulk move tool, open its dialog and click Paste. Then save, close and reload the destination layout (the wiring will not work until this has been done).

Pasting the module into another layout does not create a dependency on this mod. Neither you nor any other user of your layout will need to be subscribed to this mod thereafter.