Application Notes

This application diagram depicts an aircraft internal communication system (ICS) cabin call switch that can initiate a call and indicate system state. The switch can take external input signals of different voltage levels and invert them to provide active system state indication.

System Soft Power Startup

This application diagram depicts a power distribution control system with a staggered startup using incremental time delay components. This design provides a custom sequential startup pattern such that certain units are powered up before others and serves the dual purpose of protecting power supplies from transient spikes associated with multiple units being powered up at the same exact time.

Audio Switching

This application diagram depicts an annunciator that selects and indicates the active audio source as determined by the position of the built-in alternate action switches. The switches control external relays which allow signals of the selected audio source to be sent to downstream systems.

Load Shed

This application diagram depicts a power converter annunciator with ON/OFF, fault, and overheat status indicators. The indicator senses power signals from an external mechanical relay to determine the ON and OFF indication states. Discrete signals from the converter are used to indicate fault and overheat conditions.

Power Transfer

This application demonstrates a multiple battery power system with the ability to monitor battery voltage and automatically complete a battery switchover should primary battery voltage (BATT 1) drop below defined levels. The automatic switchover assures battery power is always available when charging is required on the primary battery. When the primary battery is fully charged, switchover can also be forced by manually latching an alternate action switch toggling between battery systems.

Dual Transponder Control and Monitoring

Dual transponder control and transponder monitoring via an ARINC 429 data bus is a common aircraft installation. Annunciators are used to report dual transponder status and an ARINC 429 decoder is typically used to provide discrete outputs to illuminate annunciators and advise of transponder status.