Kongsberg Autronica KRS-1
Buzzer and power control unit
7225-020.0004
Kongsberg 792.141.00.044 Control unit bridge alarm

The upper card is KRB-1/1, lover card is KRS-1

The buzzer unit contains besides buzzer control also pulse forming net work for buzzer
start generated direct from the main alarm in the engine rom, togeter with-
internal powr control in KR-20 and from external point (engine room).
Buzzer start pulse generated by the main alarm relay in the engine is also fed to an
eventual discordance unit (KRD-1) for detection of double signal line for acoustic signal.
Internal power failure is not giving buzzer start pulse out on common buzzer start (p6).
Power failure in engine room (normally closed contact) is fed to buzzer unit across pin
no.11. This will give buzzer start pulse, and the same time buzzer start is given from
main alarm relay in engine room accross pin no. 8 (normally closed contact).
All other acoustic alarms are given from the alarm channel's buzzer start (p6).
Buzzer signal is steady for responsibility change alarm, and intermittent for all other alarms.