Wavetek 188, Инструкция по эксплуатации

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When
the CONT switch is
released,
trigger
logic
is in­
hibited from passing any
trigge r signals and the
trig­
ge r
fIi�flop
output
is
held high.
This
prevents
the
trig­
ger diodes
from
conducting and
the gene rator loop
ope rates
continuous ly.
When
the
CONT
switch
Is pressed,
the
generator loop
is
held
at the OV
base line.
Pressing the TRIG/GATE
switch puts the
Instrument
in
triggered
mode
and
any
external or
manual trigger
at the
trigger
logic
input
will
be
transformed
into
a
narrow
pul se
cor­
responding to the low-ta-high
transition
of the trigger
input. This pulse
sets
the trigger" fIi�flop
high
and
allows the generator loop to
run.
When the
triangle
negative peak is
reached,
the comparator low-t�high
transition
clocks the trigger fli�flop low
and, when the
OV baseline
level
is reached, the
gene rator
loop again
stops. The result
is a
single
cycle generated
after
the triggering signal
corresponding
to a to 3600 of
phase. Successive
triggered
waveforms
always
start
at the
same
O· point.
Releasing the TRIG/GATE switch puts
the instrument
in the gated mode.
This
is identical to the triggered
mode, except the trigger flip-flop is
held high
for the
full duration
of
the
triggeri ng signal .
The generator
produces conti nuous
waveforms during the time the
extemal signal is high or the manual trigger switch is
4-2
held
i n .
The
last
triggered cycle started
is
always
com­
pleted
and
successive gated
bursts
always start at the
00 pOint.
When
sweep mode is selected by a combination of
the main generator
in
continuous mode and
the ramp
generator switches
set
to
SWP. the ramp
generator
is
enabled
and
a ramp voltage
becomes pa rt
of the
con­
trol voltage in
the VCG circuit to
control
the
mai n
generator frequency. Ramp
period,
variable from
30 ms to 1 minute, is
set
by the TIM E Co
n
tr
o
l
.
Ramp
generator output
is
buffered to drive the sweep output
and VCG circuit.
The
ramp magnitude suppling the
VCG input is controlled
by the
STOP potentiometer.
Selecti ng
the stop switch position biases the buffer
amplifier to a
level
equal
to
the
positive
peak
of
the
ramp
(
+
V). In
this static
mode
the upper sweep limit
can
be set by the STOP
Control .
When the CONT position of the SWEEP switch is
selected
th�
ramp
generator is disabled
and
the
buf­
fered ramp is disconnected
from the
VCG input.
The GCV
(Generator Control
Voltage)
from
the VCG
circuit is
a
resultant voltage
from
the three VCG in­
puts:
dial, VCG IN and sweep ramp. This voltage is
buffered and made
avai lable
al the GCV BNC.
Scans
by
ArtekMedia
=>
2011