Kenwood VT-183, Руководство по обслуживанию, Страница: 6 / 20

VT-183
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CIRCUIT DESCRIPTION
6) Differentiator
The oscillator output will pass through a RC differentiator
and then active the discharge circuit.
7) Up Comparator
The Up comparator will output a Up pulse when the output
of the peak hold regulation circuit is higher than the high ref-
erence voltage.
8) Down Comparator
The Down comparator will output a Down pulse when the
output of the peak hold regulation circuit is higher than the
low reference voltage.
9) Oscillator
The oscillator will generate a pulse for each 60msec, and
the pulse is use for the discharge circuit and the both
Up/Down comparator.
10) Up/Down Counter
The pulse from the UP/Down pulse control gate circuit will
trigger the Up/Down counter, and which output design the
attenuation range of the meter board.
11) Decoder
This decoder convert the 4-bit binary code from the
Up/Down counter to a 12-bit control signal which drive the
attenuator control on the meter board.
12) Up/Down Pulse Control Gate Circuit
The Up/Down pulse output from this circuit is depended on
the Mode switch. Under Hold mode, the output pulse are
generate from the Up/Down switch. On the other hand,
when under Auto mode, the output pulse are generate from
the Up/Down comparator and the Up/Down can over right
the Up/Down comparator.
VT-183(K) internet 98.6.8 9:37 AM y [ W 11