The VRB-25 provides a range of up to 22NM with a 100 Watt lamp. It was designed to meet a United States specification for an accurate and reliable replacement beacon.
This beacon can operate in remote, solar-powered locations, on unattended sites, without a lighthouse for protection, and requires maintenance no more than once a year.
More than 600 of these lanterns are in service around the world, with over 300 in North America.
The two key reasons for the success of this rotating beacon are the precision optics and the reliable rotating mechanism.
The VRB-25 optical panels were designed and manufactured by Vega to maximise the light collected from a 12 Volt, 100 Watt pre-focus marine lamp.
The lenses are moulded from optical-grade acrylic resin, and produce a beam of light that is very true and parallel - as shown in the photograph at right.
The challenge is to make all the beams with the same intensity. These lenses are accurately matched to within 5% of each other. Red and green coloured lenses are available, and the beacon is available in 6-panel and 8-panel versions.
The main challenge is to build a rotating turntable which does not require any maintenance for 10-20 years, and consumes less than 1 Watt.
The VRB-25 uses centrally-mounted ball-bearing races with rubber seals to retain grease with wide temperature range.
The motor is "direct-drive" with no moving parts to wear or break. The magnets and drive coils are at a large radius to provide high torque at low speeds.
The motor is electronically-commutated and maintains its rated speed to within 3%. An optical speed sensor provides precise feedback to the PID controller. Speed range is from 0.5 rpm to 15 rpm.