Prism Signs Small


When you choose SWARCO's small prism signs you get the latest generation of prism technology.

Variable message signs using small prism technology are used as Highway Code signs, directions signs, pictograms, and lettering in general for inner city use, as well as interurban. Due to their extremely low power consumption, prism signs are also ideally suited for solar power supply: energy is almost only required if the prisms are to be rotated.


The variable display(s) of a prism sign consist of triangular rotating bodies with side lengths of 100 millimetres, seamlessly drawn from aluminum. The prisms rest on dustproof ball bearings, lubricated for life, in a torsion-free housing. The drive mechanism is powered by a heavy duty electric motor with overload protection. An rust proof adjustable worm drive serves for power transmission.


The attractive sign housing, which can be coloured according to individual requirements, is made of aluminum and corresponds

to protection type IP 54. The prisms are either mounted flush with the front of the housing („open“ design) or installed within the housing („closed“ design).

"Closed“ version:

In the case of the „closed“ version, the prism section is covered with a plexiglass panel-mounted flush with the front of the housing. It is typically internally illuminated at night,and an integrated heater prevents the front panel from fogging up. Similar to static traffic signs, the images are realized via non-reflecting foil (Type N) or in reflection class RA1.

Mechanical image return for additional safety:

As an additional option, SWARCO prism signs can be equipped with a spring powered mechanism ensuring the sign always returns to a predefined message in case of a power outage. Once power returns, the spring energy store is autmatically „recharged“. The mechanical return device, developed by SWARCO, is protected by a European patent (Patent No. EP 15 96 352 B1).

Actuation variants:

  • Commands and feedback via switching contacts
  • RS 485 serial protocol
  • Without controller (end switch and motor wired to terminals)
  • Motor protection and timing element

Anti-Frost Control:

If equipped with proven SWARCO controllers and temperature sensors, an ice preventing procedure is possible: for temperatures below 2°C, prisms are rotated by about 10° in a forward and reverse direction at a programmable time interval (normally, every 60 minutes). This prevents prism bearing freezing and the formation of continuous ice layers on the prism surfaces.

Sample variable message applications:

  • Speed reduction signs
  • Traffic jam warning (especially in construction zones)
  • Hard shoulder running, u Freight transport controls
  • Solar powered VMS