Cross-system components are suitable for both the SI impulse system and the Dupline bus system. Compatible output signals (e.g. 24 V DC or potential-free relays) also allow these components to be used for other automation systems. In addition, these devices work completely independently. Bell transformers generate the output voltage for door signaling systems such as bells, buzzers or gongs. These short-circuit-proof, tested and certified transformers convert the 230 V mains voltage into protective extra-low voltage. Properties: short-circuit-proof thanks to PTC, tested according to EN 61558, certified by VDE and KEMA, marked with the ENEC symbol for use throughout Europe, type of installation: quick attachment to a mounting rail, installation position as desired, areas of application: bell transformers of the RK series are used to supply AC voltage to bell systems, for example. Locking systems and relay circuits used. Notes: After a short circuit, restarting is necessary by briefly disconnecting the primary side. With low load or idle, the output voltage may increase, only for short-term load. For continuous load, we recommend the use of safety transformers.