Keithley 3933A Operator's Manual page 30

SECTION 3
Operation
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(SWEEP) SINGL START IN
(SingZe-sweep
start input)
This BNC connector accepts a TTL-level signal
used to start a single sweep. A single sweep
starts at the falling edge of the input signal.
(SWEEP) MKR OUT (Sweep
marker output)
This BNC connector provides a TTL-level signal
used for sweep marker output. This signal goes
low when the frequency rises above the marker
frequency during a sweep. It remains high at all
other times.
(SWEEP) SYNC OUT (Sweep synchronous out-
put)
This BNC connector provides a TTL-level signal
for sweep synchronous output. This signal is at
low level while a sweep is progressing from the
start phase to the stop phase. It is at a high level at
all other times.
(SWEEP) X DRIVE OUT
(Sweep X-axis drive
output)
This BNC connector provides the signal for
sweep X-axis drive output. The output voltage
ranges from OV to lOV, and it increases and de-
creases according to the sweep direction, as the
sweep is generated. This output signal is in-
tended for use as the X-axis drive for an oscillo-
scope or XY recorder.
AIR INTAKE PORT
An air intake port is on the rear panel for cooling.
Allow at least four inches of clearance behind the
port and any obstruction.
When the air filter becomes dirty, pull out on the
central plastic section of the air filter housing
cover and remove the filter element. Clean the
filter element with pressurized air or wash it
with a mild detergent. Make sure that the filter is
completely dry before re-installing it in the unit.
The filter should be cleaned at least once every
three months when used in a clean environment,
or at least once a month in a dirty environment.
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23 FUSE
(Line Fuse)
The fuse holder cap can be removed with a
Philips screwdriver. Turn the cap counterclock-
wise to access the fuse. Always use a fuse with an
electrical rating that matches the input line volt-
age setting in use.
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0 -L
(Grounding terminal)
CAUTION
Immediately turn off the power to the unit if
the fan ceases to operate. Be careful not to ob-
struct the exhaust ports on the upper and
lower panels. Failure to observe these pre-
cautions may result in instrument damage.
The grounding terminal is connected to the chas-
sis of the Model 3933A. To prevent interference
and for safety, be sure to ground this terminal.
WARNING
If the Model 3933A is connected to an un-
grounded AC outlet, connect the grounding
terminal to safety ground using #18AWG
minimum wire before use.
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LINE VOLTAGE SELECTOR
(SuppZy voltage
switch)
This switch sets the Model 3933A for the correct
line voltage. Using a flat-blade screwdriver, set
the switch in the proper position for the supply
voltage in your area.
WARNING
Disconnect the line cord before changing
setting the switch position.
CAUTION
Operating the Model 3933A on an incorrect
line voltage may result in instrument dam-
age.
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LINE
(Power input connector)
The LINE connector is used to connect the in-
strument to AC power.
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