B&K Precision 4011A - Manual - Manual (Page 12)

12
OPERATING INSTRUCTIONS
DUTY CYCLE CONTROL
The DUTY CYCLE control can be used to alter the
symmetry of the output waveform, to produce
waveshapes such as those shown in Fig. 4. For a
square wave, symmetry variation amounts to changing
the duty cycle (ratio of "high" to "low" time),
effectively converting the instrument into a pulse
generator. For a triangle wave, the result is a ramp, and
with a sine wave, a distorted waveshape called a
slewed sine is produced. The Model 4011A provides
for symmetry variation from 15% to 85%.
1. Select the waveform desired either SINE,
SQUARE or TRIANGLE.
2. Engage the DUTY CYCLE switch (14) and adjust
the DUTY CYCLE control (10) for the desired
waveshape. Clockwise rotation from center results
in an increase in square wave duty cycle, and
changes the sine and triangle waves as shown in
the top waveform of each pair of Fig. 4. Counter-
clockwise rotation results in the bottom waveform
in each pair.
3. Varying the duty cycle setting results in a slight
change in frequency. Adjust the COARSE and
FINE frequency controls as required.
Figure 4. Effects of Symmetry
Variation.