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Application Tips & Recommendations
•
The Duet Plus will provide enough ring volume
for most office environments. In fact, the Duet
Plus is often used in warehouses and noisy
locations without external speakers. For LOUD
ringing, connect an 8 Ω speaker to the SPKR
terminals. The Duet Plus does not provide
maximum power to the internal speaker.
•
The Duet Plus contains a protective device
that clamps all power supply voltages above
27 V. The power supply provided by Algo was
selected specifically for the Duet Plus but if an
alternate power supply is used, ensure that it
does not supply more than 27 V at a load of
50 mA.
•
More than one Duet Plus may share a
common set of dry contacts for activation. The
detection circuit was specifically designed for
maximum life of the control contacts and up
to 50 units could safely share contacts. Also,
the test button was designed to trigger only
the unit being tested to permit singular testing.
BUT if the relay terminals on two or more
Duet Plus units are wired such that they are
reverse to each other, then two or more units
will warble continuously. Connect the units one
at a time to avoid this condition and maintain
similar polarity.
