Instruction manual

Page 6 of 12
1.2 Rear Panel
1.2.1 Line cord socket: The power amplifier is powered from the AC line using a standard
power cord terminating in an IEC320 socket in the power amplifier chassis.
1.2.2 Power/circuit breaker (mains): The PA8HF amplifier uses a
magnetic-trip circuit breaker to protect the amplifier. This switch should be
‘OFF’ during the time the shaker test system is being connected. When
switched ‘OFF’, all A/C power is removed from the amplifier, including
standby power. The circuit breaker is not the power switch and should be
switched to and left ‘ON’ after all test connections are complete. Use the
power switch or an external control voltage to power-up or power-down the
amplifier.
1.2.3 Output connector: There is a four-pin SPEAKON connector providing output to drive the
shaker or matching network.
1.2.4 Input connector: A BNC coaxial connector located on the rear panel provides the input
connection for the power amplifier.
1.2.5 Piezo filter switch: This is a toggle switch located on the rear panel. This switch allows
the user to enable the 500 Hz (-3 dB point) high pass filter required when driving piezoshakers
using matching networks. When the switch is in the “IN” position, the 500 Hz high pass filter is
selected. When the switch is in the “OUT” position, the 0.5 Hz high pass filter is selected.
Note: The piezo filter should be set to the “OUT” position when driving electromagnetic shakers
(such as the F3, F4, F5B, or the F10). Check the position of this switch if you have low output
from your electromagnetic shaker.
1.2.6 Auto/local switch: In “local” position either the front panel power switch or
an external voltage controls the power-up of the amplifier. “Auto” is used when the
amplifier is powered from a switched power outlet. The ‘POWER’ switch and / or
control voltage will function normally after the initial power up.
1.2.7 External/local switch: To power-up the amplifier using an external control
voltage, supply a 4V to 12V AC or DC control voltage to the ‘IN’ terminals of the
control voltage connector. By selecting the switch to the “external” position, the
amplifier will power-up only when the control voltage is present (on). Immediately
following power up, the control voltage will appear at the ’OUT’ terminals of the control voltage
connector for the control of other equipment. The removal of the control voltage (0v) causes the
amplifier to turn ‘off’ and the control voltage at the ‘OUT’ terminals will be interrupted. In the
“Local” setting, the amplifier will ignore the control voltage, and power up only by using the front
panel power switch. If a control voltage is present at the ‘IN’ terminals it will still be available at the
‘OUT’ terminals after the power-up sequence.
1.2.8 Ground terminal: The ground terminal in the lower right corner is available to ensure
proper ground of the test system components. Matching network ground connection can also be
made to this terminal.