Complex sentence: These have been replaced by high intensity white strobe lights flashing at a uniform rate of between 1 and 2 flashes per second, in some cases this requires electronic synchronization of appliances supplied from different sources.
Split into simpler sentences: These have been replaced by high intensity white strobe lights flashing at a uniform rate of between 1 and 2 flashes per second. In some cases this requires electronic synchronization of appliances supplied from different sources.