The PS-6 is the primary power source for the FC-72 series fire alarm control. In addition to supplying the system with 4 amperes of filtered and regulated DC, the PS-6 contains a solid state battery charger which is capable of float charging sealed lead-acid batteries, or (optionally) charging nickel cadmium batteries. The automatic high rate circuit has a controlled output to 0.9 ampere, and the end of charge voltage is automatically regulated by a solid state switching circuit. Failure of the primary power input, and/or the 24VDCpower supply output will automatically transfer the FC-72 control to its standby batteries. This will cause both audible and visual system trouble conditions.
The battery monitor circuit indicates both system trouble and battery trouble conditions if the standby batteries are disconnected, or deteriorate to 85% of rated voltage. The “brown-out” circuit detects low AC input and automatically transfers the system to battery standby. Options available are an ammeter for monitoring the charging current, and a voltmeter indicating the power supply voltage.