Figure 1-1. Audible alarm BZ-204( )IFSS-9(V).
1-9.
Description
The audible alarm is comprised of an outer and an inner
housing (fig. 1-1), the latter of which contains an
acoustical sounding device (speaker), a battery
(emergency power), electronic circuitry (power supply,
associated interconnecting electrical hardware. The
double-housing configuration affords both weather-
resistant and tamper-secure characteristics for the
contents of the housing.
1-10. Acoustic Alarm Device
The acoustic alarm device is a 25 watt, 16 ohm, per-
manent magnet, submergence proof speaker. The
speaker is mounted to the back panel of the inner
housing. The mouth of the speaker horn is oriented
toward the acoustical port provided in the housing.
1-11. Power Supply
Ac input power is routed into the audible alarm
Figure 1-1. Audible Alarm BZ-204 () FSS-9(V)
1-13.
Tabulated Data
through a 3-terminal board strip (L1-1), a toggle switch
(ON-OFF) and a 0.5 ampere cartridge type fuse (tubular
Environmental conditions (operational)
fuseholder), into the ac power supply, dc battery trickle
Temperature range ....................... -20'F to 150F.
charger and the audible ramp generator-amplifier
Humidity ........................ Up to 95 percent relative
package. An electronics package comprised of two,
Adverse weather..................................... All types
stack mounted printed circuit board assemblies in a
Environmental conditions (non-operational)
removable chassis is located in the lower right area of
Temperature range .......................-30Fto 1650F.
the inner enclosure. The package provides circuitry for
Humidity ....................... UP to 95 percent relative
part of the power supply and the audio generator-
Shock .......................... 20 gs, 11 ms duration and
amplifier. The power transformer is located at the lower
bench handling
left within the inner enclosure. A 24-volt, 2.5 amp-hour,
Vibration ....................... Transportation conditions
immobilized electrolyte, hermetically sealed battery
Weight (with battery in-
provides the emergency backup power for the audible
stalled) ............................................. 29.5 pounds
alarm. The battery is mounted within and along the left
Dimensions
side of the inner housing. The battery weighs 6.0
Height............................................. 15 1/4 inches
pounds.
Width ........................................... 12 9/16 inches
Depth ............................................. 6 5/16 inches
Color
1-12.
Difference Between Models
Housing ............................. Gray per Federal Std.
595, color chip 26492.
The information in this manual applies to all audible
Power requirement
Primary power ............................... 115-volts -a.c.
alarm units beginning with Serial Number 0001. All
Secondary power.................................... 24 V dc.
units are physically and functionally the same, with all
Alarm ........................................................... 145 dB.
components being interchangeable.
1-2
