Data Sheet

• Monitors audio activity over a wide range of
input voltages
• Two sets of C-Form (both N.O. and N. C.) relay
contacts respond to audio activity
• Four levels of signals: microphone, 600-ohm
line, 25V, and 70V speaker systems
• Built-in balanced, low noise, high gain micro-
phone pre-amp
• Transformer-isolated, 600-ohm small signal
level output of detected audio available
• Works with self-amplified or central-amplified
paging systems
• Separate microphone pre-amp gain control
• Adjustable release delay: 0.25s to 25s
• Trigger threshold adjustment
• Relay active indicator light
• Accessories: PRS40C 12V DC Power Supply
(sold separately)
Features
Description
Specifications subject to change without notice.
© 2009 Bogen Communications, Inc.
54-8023-46B 1109
Voice-Activated Relay
Model VAR1
The VAR1 is a relay device that monitors audio activity over a wide range of input voltages and operates
two sets of C-Form relay contacts in response to detected activity. The VAR1 can be used to detect volt-
ages as low as signals directly from a microphone or as high as signals from 70V speaker systems. A
low-level output of the detected audio, transformer-isolated from the input, is also made available for use
with other equipment. The VAR1 can also be used as a balanced, low-impedance microphone pre-amp.
The VAR1 is ideally suited to provide a set of contact closures for paging ports of lower cost telephone
systems that do not have a set of AUX contacts to trigger paging equipment. An adjustable release delay
(up to 25 seconds) keeps the paging system from dropping out in the middle of a page.