It just so happened that [Kevin] was in the middle of constructing a DIY residential elevator ... [Michael] built a control board that uses little more than a handful of relays and microswitches ...

OM-120 is a multiple output extension module which controls up to 12 output relays. It can be used as elevator controller with BioStar 2 system. Max. 31 units can be connected to a master device via ...

The V300 output control interface contains 12 latching Form-C relays, which can connect up to 12 devices controllable by simple contact closures, such as logic inputs for process equipment, HVAC and ...