Image showing direction sensor, a threaded metal cylinder with a cable from one end.

Direction Detection Ltd. make sensors to control trailer lights based on movement direction.

Operating Princple

Sensing is by means of a magnet on the vehicle wheel. A 50 Gauss south pole magnetic field triggers two hall effect switches, signalling the vehicle direction.

When neither sensor has detected a change within 10 seconds, the vehicle is assumed to be stationary.

Inputs & Outputs

The sensor operates from 8 to 24 volts and draws 10mA of current, along with whatever current is used to power the outputs.

Four current-sourcing outputs are available, controling white and red lights. When the vehicle moves, White lights are displayed in the direction of travel and red in the other direction. When the vehicle is stationary, red light are shown in both directions.

Each output sources 150 milliamps of current. If the sensor is used to power relay coils, flyback diodes should be fitted.

Durable and easy to mount

A durable, IP68 rated threaded stainless steel enclosure allows through-hole mounting, with two stainless steel nuts supplied.

The sensor is 25mm in diameter and 80mm long, with 50mm of M25x1.5 thread.

The sensor includes 2m of cable, supplied with conduit. Longer cables are avaliable on request.


A technical datasheet is available (235kb PDF)


Sensors can be supplied with custom branding, drop-shipped as spare parts, or fitted with longer cables. Suitable magnets can be supplied.


Sensors are held in stock for immediate dispatch. For more details or to purchase email

Direction Detection Ltd.
33 Hampstead Road, Bristol, BS4 3HL
Registered in England and Wales, Number 07538151

Copyright © 2010-2019 Direction Detection Ltd. All rights reserved.