Airmar Acoustic Deterrent System—dB Plus II™ - Manual (Page 7)

5
Operation
Power-up
Before activating the system, scan the area around the pens for the presence of divers in the water. When
the area is clear of divers, turn the power switch to the “ON” position. Note that the projectors will start
transmitting at 20% of power and take approximately 70 seconds to reach 100% power. This unique
Soft-start 
safety feature allows both divers and marine mammals time to swim a safe distance away from
the projectors thus avoiding the possibility of hearing damage.
WARNING : Before a diver enters the water within 150 m (500') of a dB Plus II

system, always turn the
power switch to “OFF” and secure it in the “OFF” position with the locking pin attached to the diver’s
cover (see Figure 4). In addition, the high visibility diver’s cover must be securely fastened over the
transmitter , signaling the presence of a diver in the water. The pin and cover shall remain in place until the
area is clear of divers.
Normal Mode
The transmitter operates in the normal mode when the battery voltage is above 22VDC. It pulses each
projector sequentially for 2.5 seconds with a 2 second off period between transmissions. The total cycle
takes 18 seconds for all four projectors to transmit. The green light on the front panel of the transmitter
indicates
normal mode when it is illuminated (see Figure 5).
Power Save Mode
When the battery voltage drops below 22VDC, the transmitter will automatically switch to the power save
mode. This extends the off period between projector pulses to 6.5 seconds. Power consumption is cut by
50% while maintaining close to full sound output from the projectors. The total cycle time for all four
projectors to transmit extends to 36 seconds. When the yellow and red lights alternately illuminate on the
transmitter and the “Insufficient Power” alarm sounds, the
power save mode is active indicating that the
batteries need recharging (see Figure 5).
Caution: Do not run the system in the power save mode for an extended period of time. This will result in
less than optimal protection from predators. This feature is designed to allow for temporary coverage until
the batteries are recharged.
COVER
PROJECTOR PROJECTOR PROJECTOR PROJECTOR
POWER CABLE I/O PORT
FUSE
SERIAL No.
ON/OFF SWITCH
Figure 4. Bottom view of transmitter
locking pin
(from diver’s cover)
BREATHER
Figure 5. Transmitter panel
BATTERY STATUS ALERT
INSUFFICIENT
POWER
TRANSMITTER
OFF
CHARGE
BATTERIES
POWER
SAVE
BATTERIES
OK
NORMAL
OPERATION
MODE
Yellow Red Green