Automatic Failure
Detector/Substitutor
Model AFDS2
Description
Features
Specifications subject to change without notice.
© 2004 Bogen Communications, Inc.
Part No. 54-7584-07B Printed in U.S.A. 04
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2
• Supervises both main and standby power amplifiers
• Automatically transfers operation to standby
power amplifier
• LEDs and fault alert tone notify user of a 2 dB* or
greater drop in either amplifier’s output
• Automatically restores operation to main power
amplifier when trouble is corrected
• Rear-panel screwdriver-adjustable controls for
setting the oscillator level and the detector levels
and sensitivities
• Operates with 25V or 70V constant-voltage
systems, balanced or unbalanced
• Screw terminal or phono jack connections
• Operates from
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20V AC or
1
2V DC
• Standard
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9-inch rack mounting
• Front panel made of #
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6-gauge cold-rolled steel,
finished in black enamel
The Bogen Model AFDS2 Automatic Failure Detector and Substitutor provides continuous electronic
supervision of the main and standby power amplifiers in a sound system, and substitutes the standby power
amplifier should the main power amplifier’s output drop by as little as 2 dB*.The changeover is almost instan-
taneous with virtually no loss of signal, thereby assuring uninterrupted performance.This device is a critical, high-
ly desirable component in systems with a dedicated emergency announcement amplifier.
The AFDS2 pulses a 40 kHz frequency into the inputs of the main and standby power amplifiers and continuously
analyzes their output. If the 40 kHz level from either amplifier should fall below 2 dB*, a fault alert tone will
sound, indicating a failure. Front, panel-mounted LEDs indicate which (main or standby) amplifier has failed.The
fault alert tone may be silenced by momentarily pressing the SILENCE button; however, the LED will stay on for
the duration of the malfunction and the SILENCE button will automatically reset when the failure is corrected.
*Threshold is adjustable.
