Wavetek 188 Instruction Manual page 24

the CONT switc h is
When
output
hibited from passing any
held high.
ge r fIi�flop is
ger diodes conducting and
f rom
ope rates conti nuous ly.
When switch
CONT Is pressed,
the
is at the OV
held base l i ne.
switch puts the
Instrument
exte rnal or
ma nual trigger
input be
will transformed
responding to the low-ta-high
input. This pu lse the trigger" fIi�flop
sets
allows the generator loop to
negative peak is
reached,
clocks the trigger fli�flop low
transition
OV baseline is reached, the single
l evel
stops. The result
is a
the triggeri ng signal
corresponding
phase. Successive
triggered
at the O· point.
sa m e
Releasing the TRIG/GATE switch puts
in the gated mode. is identical to the triggered
This
mode, except the trigg e r flip-flop is of
full duration the
triggeri ng s ig nal .
waveforms du ring the time the
produces conti nuous
extemal signal is high or the manual trigger switch is
4 -2
trigger is i n­
released, logic
trig­
trigge r signals and the
prevents trig­
This the
the gene rator loop
generator loop
the
Pressing the TRIG/GATE
in and
triggered mode a ny
logic
trigger
i nto cor­
a narrow pul se
of the trigger
transition
run.
and
high
When the
triangle
the compa rator low-t�high
and, when the
loop again
gene rator
cycle generated
after
to a to 360 0 of
waveforms sta rt
always
the i nstru ment
for the
held high
The generator
by
Scans
held The triggered cycle started
i n . last
pleted successive gated
and
00 pOint.
sweep mode is selected by a combination of
When
in
the m a i n generator
generator switches
set
enabled a ramp voltage
and
the VCG circu i t to
trol voltage in
generator frequency. Ramp
30 ms to 1 mi nute, is is
generator output buffered to drive the sweep output
and VCG ci rcuit.
The
VCG input is control led
the stop switch position biases the buffe r
Selecti ng
amplifier to a ( V). I n equal
level
ramp this static
+
be set by the STOP
can
When the CONT position of the SWE EP switch is
selected ramp
th� generator is disabled
fered ramp is disconnected
The GCV
(Generator Control
circuit is resultant voltage
a
dial, VCG IN and sweep ramp. This voltage is
puts:
buffered and made
avai lable
ArtekMedia
2011
= >
a lways
is
a lways start at the
bu rsts
the ramp
to
mode and
continuous
SWP. the ramp
generator
of the
becomes pa rt
control the
.
variable from
period,
by the TI M E Co tr l Ramp
set n o
ramp magn itud e supp l i ng the
STOP potentiomete r.
by the
the peak
to positive of
the upper sweep limit
mode
Control .
the
and
VCG i nput.
from the
Voltage)
the VCG
f r om
the three VCG in­
from
al the GCV BNC.
com­
is
con­
mai n
the
buf­