11. Information was transmitted via high-power frequency modulation. 12. The coil carries rated continuous power frequency currents, therefore this is the power inductor in this system. 13. For example, a copper foil or screen RF shield will be minimally effective against power frequency magnetic fields. 14. Near the end of life, fluorescent lamps can start flickering at a frequency lower than the power frequency . 15. These fuses open in less than one cycle of the AC power frequency ; circuit breakers cannot match this speed. 16. The Rome-Sulmona was the line for an experimental traction phase of 10, 000 volts and 45 Hz power frequency . 17. The Euroloop frequency was moved to a centre of 13.54750 MHz ( exactly half of the Eurobalise power frequency ). 18. The Independent Broadcasting Community relaunched Contact on a low-power frequency 106 MHz, before settling with its current frequency of 88.1 MHz. 19. The impedance of a line trap is very low at the power frequency and will not cause any significant voltage drop. 20. At the time, efficient high-power frequency conversion was expensive and heavy, so using standard 50 Hz mains power was the only practical system.
