Euro Manufacturing and Marketing Ltd

UK Manufacturers of

Battery Management Systems,

DC-DC Voltage Converters and DC-DC Battery Chargers

This Speed Switch offers a direct equivalent to the LS – 20 – B (3178)

This Unit was designed to switch selected equipment (such as Beacons / Side Cameras) On at a specific Road Speed.

The switching on speed is set by selecting a combination of up to 6 switches, giving 64 options between the limits of 2.5km/h (1.6mph) and 102.5km/h (64mph).

The switching on speed can be Factory set or adjusted during installation.

The output on this unit is normally off and switches on at the set speed, it is capable of switching 10A.

The tri state Override input can control the output as follows:

Open = normal operation

Switch to positive = output on

Switch to ground  = output off

Output Current


Switch On Delay (Speed Increasing)

1 second

Switch Off Delay (Speed Decreasing)

< 12ms

Switch point Setting (See Table)

6 Way Switch

(64 Combinations)

Pulse Input

V low < 1.5V

V high > 5.5V

Pulse Duration > 1.5ms

Override Input Resistance

> 5k to ground

Override Input


Operation normal

< 1V

Output Off

> 4.5V

Output On

Case Style

Din Pack, Vertical bracket


94 x 61 x 45 mm




1 x 6.3mm Hole

Case Material

Black ABS

Bracket Material

Aluminium Alloy

 Note: All road speeds assume 4 pulses per metre

Note: Pin 1 and Pin 6 should be wired directly to the appropriate Pins on the Tachograph as indicated.

For example on the DTCO 1381 Tachograph:

· Pin 1 of Speed Switch to Tachograph Plug B Pin B8

· Pin 6 of Speed Switch to Tachograph Plug A Pin A6

Setting Information

E1048 12v + 24v Digital Speed Switch

E1048 12V / 24V Digital Speed Switch

Cross Reference LS – 20 – B (3178)