Signal-light systems, especially for a series of emergency-phone stations distributed along the length of a highway, or the like

摘要

Emergency phone stations distributed at intervals of 1 or 2 km along a highway area and connected to a communications channel with a power line. Each phone station has a set of flash lamps which can be blinked in accordance with differing blinking schedules, and with a storage capacitor which stores flash energy. When a lamp is flashed, the storage capacitor discharges from the power line, the charging time- constant of each station being different due to differing distances from a central station. To impose an order on the network, central clocking is employed, with lamp ignitions occurring at each individual station being referenced to clocking signals common to all stations, so that the blinking schedules at all activated stations have a fixed phase interrelationship. This predetermines the times and sequences at which the storage capacitors will recharge. All storage capacitors are identical and are so selected that t.sub.0 /R.C.sub.ges =0.5 to 3, preferably 1.25, t.sub.0 being the charging time allotted, C.sub.ges being the combined capacitance of the maximum number of stations which can be simultaneously flashed, and R being the charging resistance to the most distant station. This transfers maximum energy to the storage capacitors. The recharging of each storage capacitor is discontinued when a predetermined amount of energy has been accumulated. Flash energies at the nearest and most remote stations are thus equalized.