2. Set the starting frequency with the COARSE control.
Apply a positive DC voltage to the VCG/SWEEP input
jack (9) to decrease the frequency. A voltage from 0 to
+10V will cause the frequency to decrease by a factor of
100 if the COARSE frequency control is set at
maximum CW rotation. For example, if the starting
frequency is 100kHz, applying +10V will change the
output frequency to 1kHz.
3. To operate the function generator as a sweep generator,
apply a positive going ramp signal to the VCG/SWEEP
input jack. As the ramp voltage increases, the frequency
decreases. The rate of sweep can be adjusted by varying
the frequency of the ramp signal.
4. Specific frequencies can be selected by applying a fixed
dc voltage to the VCG/SWEEP input jack or the
frequencies can be stepped by applying a stepped dc
voltage.
5. Do not apply more than ±15 volts (AC or DC + AC peak)
to the VCG/SWEEP input jack. Inputs of more than 15
volts will not cause any further shift in the frequency and
could cause damage to the generator.
OUTPUT PROTECTION CONSIDERATIONS
Use care when connecting the function generator output to a
signal injection point. Excessive voltage at the point of signal
injection of the function generator can cause internal damage.
Under normal operation, the generator output should never be
connected to an external voltage other than low dc values that
can be matched with the DC OFFSET control. The Model
4017A is overload protected so that shorting the output, even
continuously, will not cause damage. A fuse has been added in
series with the OUTPUT jack to help protect the instrument
from damage by connection to excessive external voltage.
OPERATING INSTRUCTIONS
Damage of this type usually occurs by accidentally
connecting the output of the function generator to a voltage
in the equipment under test. The following protective
measures are strongly recommended:
1. The user should understand the equipment under test
2. If in doubt about the safety of a signal injection point,
3. When applying the main output of the function
4. Connect the TTL output only to TTL-level circuits.
5. When the function generator is used by students or
13
well enough to identify valid signal injection points
(i.e.: the base of a transistor, a logic input of a gate,
etc.). The voltage at valid signal injection points is
rarely high enough to damage the instrument.
measure the voltage present at the intended point of
signal injection before connecting the function
generator output to that point.
generator to a circuit point containing a dc level, adjust
the DC OFFSET control so that the dc level at the
main output matches the circuit voltage.
Connect the CMOS output only to CMOS circuits.
Measure the Vcc of the circuit under test and adjust the
CMOS LEVEL control as instructed in the manual.
other inexperienced users, the circuit of Fig. 5 could be
added into your TTL output probe or test clip set. It
will protect the TTL output of the generator against
external voltages up to ±20 volts.