ACR&Artex Megaphone - Manual (Page 5)

5 Y1-03-0014 Rev. AC
FIGURE 1
BLOCK DIAGRAM
ACR/EM-1A, ACR/EM-1D PORTABLE SAFETY MEGAPHONE
SECTION 3 – MAINTENANCE
3.1 Cleaning
External surfaces of the megaphone may be cleaned with a soft cloth, dampened in a
solution of mild household detergent. Do not immerse in water or use strong solvents. Clean
electrical contacts with a cloth dampened with isopropyl alcohol.
3.2 Battery Replacement
The power supply used in the megaphone consists of six standard 1½ volt “AA” size batteries.
Current drain is minimal (1 mA) with the megaphone “ON”, and increases when the user
speaks into the microphone.
Battery replacement is accomplished by removing three set screws () while holding the
microphone and mouthpiece assembly (1) in place. The six cells, contained in three tubes
with two cells per tube, are immediately accessible and will drop out when the megaphone
is tilted. New batteries may be dropped into the tubes, observing polarity marking adjacent
to each tube.
Replace microphone and mouthpiece assembly (1). Align keyway and secure with the three
set screws ().
CAUTION: Observe polarity of cells carefully before replacement.
SECTION 4 – TESTING, TROUBLESHOOTING & REPAIR
4.1 Testing
Note: The megaphone consists of three major assemblies; the microphone and
mouthpiece assembly, the megaphone sub-assembly, and the horn and speaker
assembly. To locate a defect, follow the procedure outlined below:
1. Squeeze the handle. If a clicking sound is heard, the speaker is operating.
VOLUME
CONTROL
MICROPHONE
ASSEMBLY
AUDIO AMPLIFIER
SIREN CIRCUIT &
BATTERY MONITOR
MEGAPHONE
SUB-ASSEMBLY
BATTERY
PACK
(6 x AA)
LED
VISUAL
BATTERY
CHECK SPEAKER
ASSEMBLY
N.O.
N.C.
HANDLE
SW ITCH
ALARM
PLUG PIN
+ +
+ -
-
-
*