Bogen AFDS2 User manual

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. 0412
• 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 120V AC or 12V DC
• Standard 19-inch rack mounting
• Front panel made of #16-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.

Supervision Frequency: 40 kHz
Supervision Frequency Level: 5mV to 50mV into 47 kilohms
Input Impedance: Medium-Z 10 kilohms
Detector Input Signal @ 40 kHz: 2V
Detector Supervision Range: 2 dB (min.) to 12 dB (max.)
Failure Indicators: LEDs (visual) and tone module (aural)
Controls: Screwdriver-adjustable controls for oscillator level
and detector sensitivity
Remote Annunciation: Status terminal provides 12V DC / 100 mA in the
failure mode
Power Consumption: 120V AC, 15W or 12VDC @ 0.5A
Operating Temperatures: 14° F (-10° C) to 149° F (65° C)
Dimensions: 19" W x 3-1/2" H x 7-1/2" D
Weight: 8 lb.
Finish: Black enamel
Architect &
Engineer
Specifications
Technical
Specifications
50 Spring Street, Ramsey, New Jersey 07446, U.S.A.
201-934-8500 FAX: [phone]
Web Site: www.bogen.com
The amplifier failure detector and automatic substitutor
shall be a Bogen Model AFDS2, or equivalent, capable
of continuously supervising the operation of any main
power amplifier and its standby amplifier in a sound
system.
It shall be capable of detecting a loss of as little as 2 dB
in either amplifier and automatically switch operation
from main to standby amplifier, should the main
amplifier be at fault.The failure of either amplifier shall
be indicated by a corresponding front, panel-mounted
LED and an aural fault alert tone. It shall be possible to
silence the tone by depressing the SILENCE button,
which shall automatically reset when the failure is
corrected.
A 40 kHz signal, originated within the AFDS2, shall be
pulsed into the inputs of the main and standby
amplifiers and their outputs shall be continuously
analyzed; if either amplifier should fall below 2 dB*, the
AFDS2 shall be activated.
It shall be suitable for operation with, and capable of
detecting failure in, any 25V or 70V balanced or
unbalanced system.
The device shall be powered from either a 120V AC,
60 Hz line or a 12V DC source, with power
consumption limited to 15W or 0.5A, respectively.
Screwdriver-adjustable controls shall be provided on
the unit for setting the sensitivity of the device and the
level of the 40 kHz oscillator.
The unit shall be 19" W x 3-1/2" H x 7-1/2" D and
shall weigh 8 lb.The panel shall be fabricated from #16
gauge cold-rolled steel and shall be finished in black
enamel.
*Threshold is adjustable.