V690 Automatic Voice Alert Device
AVAD (Automatic Voice Alert Device) is a highly versatile
voice alerting system. It stores pre-recorded human speech in
digital form and operates under microprocessor control to assemble
messages from words and phrases, held in the store. AVAD’s voice is
not synthesized and can be in any language, male or female,
providing the right degree of stress and urgency for each
situation. The quality of speech is so good that the speaker’s
voice remains recognisable and highly intelligible even under
stressful environmental conditions, such as noisy cockpits and
armoured fighting vehicles.
The message priority order, repetition rate
and volume are preprogrammed to individual customers’ requirements
to give the maximum information to the operator without disrupting
performance of his primary task.
AVAD incorporates the benefit of research,
conducted by the British Medical Research Council from which
psychologically engineered attention tones have been derived and
approved by the CAA.
This one compact unit integrates and controls
all the voice messages and audio tones required in any complex
system. Automatic message priority regrading is available where
required recognising the fact that message priorities may vary from
situation to situation. The unit may be ‘keyed’ from most types of
sensor and will accept a wide range of trigger voltage levels. It
also has built-in test and continuous self-monitor facilities for
added user confidence.
AVAD can replace all existing discrete audio
warnings thus reducing the installation cost and complexity of new
projects. It is also simple to retrofit.
Advantages of AVAD
- High Quality human speech
- Faster crew/operator response
- High intelligibility in noise
- Appropriate message emphasis
- Microprocessor control of message format
- Any voice in any language
- Low disruption, noise penetrating attenson
tones available
- Message priority sequencing with regrade
capability
- Mix of tone and voice outputs
- Continuous self-monitoring
- Simple to re-programme
- Simple, low cost installation
Technical Description
V694
The AVAD V694 is designed to integrate and
control audio alerts, be they voice or tone, and is activated by
‘keying’ signals from remote system sensors and/or push buttons.
The message format is completely flexible and, for example, in
civil aviation circles, AVAD conforms to ARINC 577 ‘Audible Warning
System’ and ARINC 726 ‘Flight Warning Computer System’.
Approximately sixt-four seconds of
pre-recorded human speech can be digitally encoded and stored as a
vocabulary of messages, phrases, words and tones. Messages can be
constructed using words and phrases drawn from unit memory under
software control, allowing the total duration of all message
outputs to exceed the vocabulary capacity by a considerable amount.
High quality reproduction is achieved with an advanced digitised
speech technique and selective analogue filtering within the unit.
Up to 16 message channels offer +ve or OV keying. The unit will
respond to single an multiple keys. Four analogue channels can
respond to variable d.c. voltage inputs offering a sensitivity of
up to 256 logic switching steps across the input range. A
stabilised 5 V d.c. output is available for use as a reference for
an external potentiometer. Typical variable readouts might be
aircraft height, voltages or pressures.
Unit operation and vocabulary store may be
defined by the user, (programme software allows control of each
message cycle). Each message has Normal, Regrade and Test priority
values assigned to it. The output sequence is then controlled by
the regrade and test inputs. The audio outpurs are provided: one at
telephone/headset level and the other for driving a loudspeaker
direct. The nominal level of each output can be set by individual
preset potentiometers offering 20dB range with the relative volume
of each message or message repeat under the control of operating
software. The complete message format, including a repetition rate,
pauses, message inhibit/de-inhibit, and tones may be similarly
controlled.
A key input is provided which will inhibit any
message in progress without affecting other keyed messages. The
message thus inhibited would normally remain so until its sensor
input is removed and reapplied. Alternatively, the inhibit may be
removed after a specified time, if the warning message keyline
remains activated during this period.
Full test/reset facilities provide fast
checking of unit operation. Correct operation of the microprocessor
and amplifier circuitry and control programme status are
continuously self-monitored. In the event of a fault condition both
audio outputs are automatically inhibited and a ‘fail’ output is
provided to activate an indicator to warn of unit failure.
V695
The V695 is a smaller 7 channel unit with
microprocessor control offering all the programming flexibility of
the V694 and storage capacity of 8 seconds.
V691
The V691 is a single output device ideal for
applications where only one warning such as ‘fire’ or ‘pull up’ is
required. A second keyline may be used to provide a ‘system
enable/disable’ input. The output repeats continuously when
keyed.
V696
This unit offers similar facilities to V691
but the message is output once only in response to valid keys.