RTS CS9500, Руководство пользователя

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While we socket the ICs that have the greatest potential for
failure, most of the Telos One
ICs
are soldered
in.
That's because
most of the time the socket
is
more likely to cause trouble
than
the
IC. This
is of no consolation when one of the soldered
ICs
appears
to have failed. When you need to replace a soldered-in chip, the
right tool is essential. We use a vacuum desoldering system made
by Pace (the MBT-100) and
highly
recommend it. Cost is about
-
worth it if you do much PC board troubleshooting work. The
only other real alternative
is
to clip the leads from the top
and
remove the solder from the holes with solder-wick. We've not
had much luck with the non-heated, manual vacuum desoldering
devices such
as
the one sold by Radio Shack We do not recommend
that newly soldered connections be defluxed.
Digital Signal Processing
Because the Telos
One
hybrid makes use of digital signal
processing for functions traditionally done in analog, the
hardware design of the hybrid
is
relatively uncomplicated and
straightforward. In many ways, the hardware is a
implementation of a general-purpose processing system.
As in any system, the input
signals
are passed through anti-
aliasing low-pass filters to remove signal components above the
Nyquist frequency. In
this
case,
the Nyquist
is 4
and
the ultimate sampling rate
is 8
After A/D conversion, the signals
are
presented to the
processor, where software the hybrid and processing
Then,
the signals are converted back to analog and filtered to "re-
construct" the desired analog audio.
Notation
Whenever a slash ( ) is used after a signal designation in the text
or on the
s c h e m a t i c s ,
an active low is
ON€ TECHNICAL DATA and TROUBLESHOOTING
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