1Housingdrive enclosure at the rail head
2Railtrack with toothed belt loop
3Motorquiet gearmotor driving the belt
4Carriergrippers on the leading curtain edges
5Light sensordawn / dusk lux reading
6Computerlogic + holiday-mode randomizer
7Clockreal-time clock, survives power cuts
8End stopsfully-open / fully-closed detection
9Power supplymains adapter with battery backup
10Remote interfaceholiday mode switch, manual override