AE Techron 7800 Series Operation Manual page 22

In Controlled-Current Mode, the load is part of the ampli-
fier circuit, and the relationship of the load to the amplifier is
critical. For proper and safe operation in Controlled-Current
mode, you must observe the following guidelines:
1. Properly attach a load before operating the amplifier.
2. DO NOT use a blocking capacitor. The load must have a
DC path.
3. Never leave the load open. If you feel the load must be
fused, which could lead to a potential open circuit, please
contact AE Techron Technical Support.
4. Make sure the load has some inductive component.
5. Provide appropriate compensation for the load.
6. If oscillation occurs, turn off the amplifier immediately.
Failure to follow these guidelines may result
in damage to the amplifier or load.
SW#2: Compensation (CC1/CC2)
When a 7800 series amplifier is used in Con-
trolled-Current mode, the current control loop is
tuned with an RC network on the Master amplifier
module. Place the Compensation DIP switch in the
Up position (default) to enable the factory-installed
RC network (CC1). This network consists of a 68.1
kΩ resistor in series with a 47 nF capacitor. Place
the DIP switch in the Down position to select CC2
network. This network is unpopulated, but can be
populated with a custom compensation network
to fit your requirements. For more information
on Controlled-Current operation and installing a
custom compensation network, see the "Applica-
tions" section of this manual.
SW#3: Low-Pass Filter
The Low Pass Filter function inserts a 50 kHz (3-
dB down) low-pass filter at the amplifier input to
ensure that signals above 50 kHz are not ampli-
fied.
Place the Low-Pass Filter DIP switch on the Mas-
ter amplifier module in the Up position (default) to
disable the low-pass filter. To enable the low-pass
filter, place the DIP switch in the Down position.
SW#4: Gain (20/6)
When the Gain DIP switch on the Master amplifier
module is in the Up position (default), the ampli-
fier's maximum gain will be 20:1. Placing the DIP
switch in the Down position will change the ampli-
fier's maximum gain to 6:1.
22
CAUTION
Information subject to change
7800 SERIES OPERATION – SECTION 4
SW#5: Electronic Gain Matching
NOTE:Do not change the setting of this DIP
switch. It is required for proper functioning of
the amplifier system.
The Electronic Gain Matching function serves to
minimize circulating currents when multiple ampli-
fiers are used in a parallel configuration. When
enabled, the Electronic Gain Matching function
progressively increases impedance from the volt-
age gain as current increases, up to a maximum
0.10-ohm increase. This allows the amplifiers to
operate in parallel without the use of separate
ballast resistors in multi-amp applications up to 20
kHz.
When this switch is in the Down position, Electron-
ic Gain Matching is disabled. When the Electronic
Gain Matching DIP switch is in the Up position, the
Electronic Gain Matching function is enabled.
SW#6: Master/Follower
NOTE:Do not change the setting of this DIP
switch. It is required for proper functioning of
the amplifier system.
When the Master/Follower DIP switch is in the Up
position (default), the amplifier will function as a
stand-alone amplifier or as a Master amplifier in
a multi-amp system. When this switch is in the
Down position, the amplifier will function as a Fol-
lower amplifier in a multi-amp system.
SW#7: Voltage Input (Low/High)
NOTE:Do not change the setting of this DIP
switch. It is required for proper functioning of
the amplifier system.
When the Voltage Input DIP switch is in the Up po-
sition, the amplifier can be configured for use with
alternate multi-amp connectors in a multi-amp sys-
tem (not available on 7800 series models). When
this switch is in the Down position, the amplifier
can be configured for use with standard multi-amp
connectors in a multi-amp system.
SW#8: DC/AC Coupling
When the DC/AC Coupling DIP switch is in the Up
position (default), the amplifier can receive and
amplify both DC and AC signal. When this switch
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