Dolby Laboratories CP650, Руководство по установке

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Dolby
®
Model CP650 Installation Manual Installation
2-5
2.5.2 Remote Controls
Three types of remote controls can be used with the CP650. A maximum of three
remote units (in any combination) can be used.
The Cat. No. 779 CP650 Remote Control Unit duplicates the front-panel format
selection, fader, and mute functions of the CP650.
The Cat. No. 771 Remote Fader Unit duplicates the front-panel main fader knob
and level display of the CP650.
A customer-supplied 100 k
ȍ
linear pot , wired as a variable resistor, can also be
used. Minimum pot resistance corresponds to a front-panel fader setting of maximum
(10).
Details on how to connect any of these remote controls to the CP650 are shown in
Chapter 8.1 and in the
Installation Wiring Input and Control drawing located at the
end of this chapter.
2.5.3 Solar Cell Reader Boards
Most new projectors sold around the world incorporate a reverse-scan LED analog
soundhead reader. In addition, many existing projectors are being upgraded to include
this superior method of playing back SVA soundtracks. The Dolby Cat. No. 655 solar
cell preamp board is an example of this kind of upgrade. The output of the solar cell
in this system is at a lower level than a normal incandescent exciter lamp solar cell. In
order to provide the correct signal level for the cinema processor, this small preamp
board is mounted in the soundhead. Some care needs to be given to the wiring
between the board and the CP650 in order to avoid grounding problems and to
provide immunity to RF interference. In principle, this means separating the audio
ground connections and the RF shielding screen connections.
The 0 V point (audio ground) must be connected from the inboard reader board to the
CP650 by a separate wire (or wires) along with the audio signal wires. The cable
shield (screen) must be kept separate from the audio ground connections. It must be
connected only to the chassis or enclosure of the equipment at each end.
The following diagrams show two connectors on the Cat. No. 655 circuit board. The
three-pin connector, J1, is used for the power connections. The signal output
connector, J2, provides six output pins: two each for the balanced left and right
outputs, and two 0 V audio ground connections.
The physical orientation of the board mounting in the projector and the orientation of
the connector body mounting on the board affect which channel appears on which pin
of the connector.
Be aware that pin allocations for the channels will vary
depending on mounting arrangements of the board and connector . The J2
connector pin solder hole with a square outline is pin 1.