Abstract: The invention relates to a burglar alarm arrangement, which can be installed in a mechanical lock, which mechanical lock comprises at least a lock cylinder (204), a lock frame (208) and a turn knob (214). A burglar alarm arrangement according to the present invention can be installed in a mechanical lock without a need to change keys, rekeying the lock or without adding code systems. Additionally, the burglar alarm arrangement can identify an authorized opening of the door by use of the key or the turn knob, and deactivate the alarm system for that time. The burglar alarm arrangement comprises an alarm system and first means (206) and second means (212), which first and second means (206 and 212) are functionally connected to the alarm system.

Abstract: The invention relates to a burglar alarm arrangement, which can be installed in a mechanical lock, which mechanical lock comprises at least a lock cylinder (204), a lock frame (208) and a turn knob (214). A burglar alarm arrangement according to the present invention can be installed in a mechanical lock without a need to change keys, rekeying the lock or without adding code systems. Additionally, the burglar alarm arrangement can identify an authorized opening of the door by use of the key or the turn knob, and deactivate the alarm system for that time. The burglar alarm arrangement comprises an alarm system and first means (206) and second means (212), which first and second means (206 and 212) are functionally connected to the alarm system.