Communications Systems LBB 1938/20 Plena Power Amplifier
LBB 1938/20 Plena Power Amplifier
www.boschsecurity.com
The LBB 1938/20 is a powerful 480 W power amplifier in a 3U high 19”case for rack mounting or tabletop use. LEDs on the front panel show the status of the amplifier: power, audio output level, and supervised functions. This
Functions
Dependability
The amplifier is protected against overload and short circuits. A
The unit operates both on mains power and on a 24 V battery power supply for emergency back up, with automatic switchover.
For emergency and evacuation use, the following functions are monitored: mains presence, battery present, pilot tone presence, amplifier operation.
Front panel LEDs indicate the status of supervised functions. The LEDs of pilot tone supervision and
u480 W power amplifier in a 3U high 19”housing
uEN 54‑16 certified and EN 60849 compliant
u70 V / 100 V and 8 ohm outputs
uDual inputs with priority switching
u100 V input for slave operation on 100 V speaker line
battery status can be switched off for general public address use. Failsafe (normally energized) relays are provided for each supervised function. These relays are always active regardless of the switches on the rear panel.
Input
The system has two balanced inputs with priority control, each with a
Gain or level control is located on the rear of the unit to avoid accidental setting change. A meter with LED- bar shows the output level.
Output
The amplifier has 70 V and 100 V outputs for constant voltage loudspeaker systems and a low impedance output for 8 ohm loudspeaker loads.
The LBB 1938/20 has two separate priority controlled 100 V outputs for zones that only need announcements made via the priority input, and for zones that will not get any announcements made via the priority input.