Leitch 880 Series, Инструкция по эксплуатации

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880 Series Audio Distribution Amplifiers Instruction Manual 41
Chapter 12: ATG-880 Audio Tone Generator Module
Preliminary—Contents are proprietary and confidential. Do not photocopy or distribute.
Output Stage
The output stage accepts the signal from the 68
µ
F capacitor and converts it to a
balanced signal by means of buffer IC1C and inverter IC1B.
The signal from pins 7 and 8 of IC1 is taken directly to output drivers IC3A,
IC3B, IC3C and IC3D which buffer the 8 dBm Outputs 1 and 2. Each
subsequent output pair is taken from pins 7 and 8 of IC1 trough a resistive
network that attenuates the signal to the desired levels before being buffered by
their corresponding output drivers. The outputs numbered 2, 4, 6 and 8,
representing the left channel of each output pair, are bridged prior to the output
driver by analog switch IC8 and a pair of 100k resistors. A high level on the
control line of the analog switches will cause them to close and turn off the left
channel of each pair. Closing the IDENT switch will enable multivibrator IC2
and thus cause the left channel of each pair to be pulsed off and on at about once
per second.