LRAD
450XL
GENASYS INC.
Manual Part No.: 112343-00 Rev. E
32
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Try connecting to a different USB port on the computer. Some systems such as laptops with
docking stations and USB hubs may give intermittent USB device recognition errors.
11.0 System Tests
The following tests may be performed periodically to verify system performance and integrity.
11.1 Driver Resistance Test
Each of the two drivers in the LRAD Head Unit should measure a DC resistance of approximately
4.5 Ohms +/- .5 Ohms. If a driver were to fail, it would typically measure open, although a short
may be possible as well. Perform the following steps to check the Driver Resistance:
•
Remove the Amplifier Module and disconnect the speaker cable from the back of the Head
Unit to expose the pins on the connector inside the Head Unit.
The pin layout for this connector is shown below.
Figure 22: Head Unit Speaker Connector
•
Using a standard handheld Ohmmeter, check the resistance between pins 1 and 2. It should
measure approximately 4.5 Ohms. Perform the same check on pins 6 and 7. Note any pair
that measures open, short, or out of range.
•
Replace any faulty Driver following the Driver Replacement Procedure in the Repairs and
Spares section of this document.
Pin 1: Driver 1+
Pin 2: Driver 1-
Pin 3: GND
Pin 4: Not Used
Pin 5: GND
Pin 6: Driver 2+
Pin 7: Driver 2-
1
2
3
4
5
6
7
