The device is designed for relay-operated automotive flasher modules to detect outage of flasher bulbs on cars and trailers. IT integrates two thresholds for outage detection. The first threshold detects outages of of 1 of 2 lamps. If the current drops below the first threshold, the IC switches to frequency doubling, just like standard flashers. The second threshold detects outages of 1 of 3 lamps, at which point the additional trailer pilot lamp is switched off, but without frequency doubling.
