Instruction manual

9-12
Section 9-7 - SAA
-
80S/SE (Supervised Audio System Amplifier/Signal
Circuit Module, 80 Watts)
Wheelock, Inc. Part Number: SAA-80S – 105495, SAA-80SE - 105496
The supervised audio system amplifier/signal circuit module, 80 watts (SAA) provides audio
amplification for the SAFEPATH
®
Panel. The amplifier can be selected to have either a 25V or a
70.7V audio output. The SAA-80SE (Export version) has only a 100V audio output. The amplifier
contains a switch mode power supply, a linear amplifier, and supervision circuitry.
The switch mode power supply is used to provide a constant DC voltage to the amplifier while the
input voltage is allowed to fluctuate over its operating range. The amplifier amplifies the low-level
600-ohm audio to 80 watts output. The supervision circuit monitors field speaker wiring integrity,
field strobe wiring integrity, and amplifier functionality.
The board of the SAA-80S can be field configured for either 25V or 70.7V output. The
configuration is done using a two-position slide switch (S1) on the printed circuit board. The
down position configures the amplifier to have a 25V audio output and in the up position
configures the amplifier to have a 70.7V audio output. See Figure 9-7 on Page 9-13for switch
location.
The board of the SAA-80SE is configured for a 100V output only. The two-position slide switch is
removed.
The amplifier supervises both the strobe field wiring and the speaker field wiring with a DC
current. The strobe field wiring is supervised with a reverse polarity technique, which applies a
DC voltage with one polarity to supervise the wiring and then reverses the polarity to energize the
strobes. The speaker field wiring is supervised with a DC current, which is removed when audio
is being played. Both field-wiring circuits are only supervised in the standby state. The amplifier
is supervised by monitoring the amplifier output for audio. The state of each of the three
supervision features is indicated via three LEDs on the printed circuit board. See Figure 9-7 on
Page 9-13 for LED locations.
There are two fuses on the printed circuit board, F1 and F2. Fuse F1 is the main fuse for the
entire board. F2 is the fuse for the strobe power. See Figure 9-7 on Page 9-13 for fuse locations.
Two UL LISTED 10K Ohm, 1W, EOLR Resistors are included.
Fuse
Rating
F1 10A
F2 3A
Nominal Specifications:
Rated Output @ 1kHz 80 Watts
Input Sensitivity 1Vrms
S/N Ratio 72dB
Frequency Response 275Hz to 6KHz
Input Voltage Range 24VDC
Supply Current (Standby) @ 24VDC 600mA
Supply Current (Full Load) @ 24VDC
(Including 2.0 Amps Strobe Current) 4.5A
Operating Temperature Range 0 to 49 Degrees C (32-120
Degrees F)