The ZSP100-BS series of access control power supplies are solutions that combine the functions of a power supply and an enclosure for Bosch access control units. The devices have been designed to provide full 24 V DC power supply functionality, along with space for modules and the access control system controller. As a result, they serve as a practical and compact power supply centre, facilitating the installation and maintenance of the entire system. The unit includes a voltage converter, additional space for batteries and signalling circuits that allow operating parameters to be monitored. The system provides information on, amongst other things, battery status, overloads and circuit faults, and also enables the measurement of battery circuit resistance. The power supply unit complies with the requirements of the EN 54-4 standard, and its reliability is confirmed by a Certificate of Constancy of Performance issued by CNBOP-PIB. The ZSP100-BS has been designed for continuous operation in demanding conditions, giving installers and users the assurance that the access control system will remain fully operational in critical situations. By combining the power supply and housing in a single unit, these devices provide a modern and effective solution for Bosch access control systems.