Studio Technologies 76B 2012 - Manual (Page 13)

Model 76B/77B User Guide Issue 3, August 2012
Studio Technologies, Inc. Page 13
for Surround
The Model 77B requires a minimum of
9 volts DC, 100 milliamperes maximum for
correct operation. (The voltage must be
measured directly at the Model 77B’s 9-pin
connector.) So the maximum interconnect-
ing cable length is directly related to the
resistive voltage losses associated with the
two DC-carrying conductors. As the Model
76B supplies 12 volts and the Model 77B
requires 9 volts minimum, this directly leads
to a 3 volt DC maximum drop due to the
interconnecting cable. Using Ohm’s law it’s
quite easy to determine whether the select-
ed cable will support the desired intercon-
nection length. Calculate the voltage drop
by multiplying the total resistance (in ohms)
of the proposed cable by 0.01 (the square
of the Model 77B’s maximum required cur-
rent). Remember to include the resistance
in both the DC + and DC – wires in the
figure for the total resistance.
AC Mains Power
The Model 76B is internally configured to
operate from nominal 100, 120, or 220/240
volts, 50/60 Hz. Units shipped to North
America are factory selected for 120 volt
operation. Units bound for Japan are gener-
ally selected for 100 volts while our friends
“down under” and in Europe receive units
set for 220/240 volts. Before connecting
the Model 76B to AC mains power, check
to be certain that it is configured to match
the local mains voltage. Look on the back
panel (adjacent to the power entry con-
nector) for an indication of the factory-
configured voltage. Note that an incorrect
configuration could prevent operation or
cause damage to the unit. Should it be
necessary to change the unit’s operating
voltage it must be performed only at the
factory, or by a factory-authorized service
technician.
The Model 76B uses an IEC-standard C14
inlet connector to mate with the AC mains
cord. The AC mains cord should have a
C13 socket affixed with the wire colors
conforming to the internationally recog-
nized CEE color code:
Connection Wire Color
Neutral (N) Light Blue
Line (L) Brown
Protective Earth (E) Green/Yellow
Safety Warning: The Model 76B does
not contain an AC mains disconnect
switch. As such, the AC mains cord
plug serves as the disconnection
device. Safety considerations require
that the plug and associated outlet be
easily accessible to allow rapid discon-
nection of AC mains power should it
prove necessary.
As soon as AC mains power is applied,
the Model 76B Central Controller’s power
LED will light steadily. The two data activ-
ity LEDs, control console and metadata,
may also light. The one or more con-
nected Model 77B Control Consoles will
go through a power-up sequence, lighting
Signal Pin Direction
Data + 1 To/From Model 77B
Data – 6 To/From Model 77B
Data Shield 2 To/From Model 77B
DC + 4 To Model 77B
DC – 9 To Model 77B
DC Power Shield 5 To/From Model 77B
Note: Connector type on Model 76B is 9-pin D-subminiature
female (DE-9F). Connector uses 4-40 threaded inserts
for locking with mating plug.
Figure 6. Connections between Model 76B and
Model 77B