The French Company of Applied Electronics (Sofrela) was founded in 1981 in Puy-de-Dôme. The company manufactured equipment for regulating and analyzing road traffic, but also a pedestrian signal and a repeater.
Several patents were also filed in 1985, then in 1991 for LED devices with E27 socket to be installed in lights to replace incandescent sources.
Sofrela was then taken over by SIAT, a company specializing in collecting traffic data, which was itself taken over by the Somaro group (now Aximum).
Sofrela pedestrian signals, repeaters and traffic counters were then marketed for some time under the EL-SI brand.
Today, only the Cigale counter is still marketed by Aximum Electronic Products.