NF FRA5097, Instruction Manual

Page: 87 / 192

4.5 Oscillator setting
FRA5097 4-13
[ON/OFF MODE]
Set the oscillator output ON/OFF mode.
[QUICK] : The oscillator output is immediately set as soon as an ON/OFF key is pressed.
[SLOW] : The oscillator output gradually changes, taking approximately 10 seconds.
If you switch the oscillator output voltage on or off while [SLOW] is set, the oscillator output
voltage changes slowly, but not quickly or instantly. This function of the FRA5097 is
especially effective, for example, not to cause shocks to a vibrator when the FRA5097 output
is fed to the vibrator via a power amplifier.
The rate of change in the output level is as shown in the figure below.
Time
OFF
Set value No.1
Set value No.2
Set value No.3
AC and DC
output voltage
approx. 10 second
s
The output level changes
with such a rate that the time
period of 10 seconds is
required for the signal level
to reach the set level from
zero (0) V, or vice versa.
(A) (B)
Fig. 4-8 Oscillator output voltage variation in the SLOW status
The oscillator output voltage level changes continuously when the oscillator status is “off” either
at the start or the end of the SLOW operation; i.e., changing the output from off to on or from on
to off. Note, however, that, when no “off” status is involved at the start nor the end of oscillator
output voltage level change (e.g., from the set value No.1 to No.2, from the set value No.2 to No.3,
etc.), a spike-like discontinuity for the duration of about 10 ms appears at the oscillator output
voltage at the timing of (A) or (B) in the figure above (Fig.4-8).
Setting [SLOW] is valid only when the oscillator stop mode [STOP MODE] is at [ZERO] (See
“Fig. 4-7 Oscillator stop mode”). However, if you change the [STOP MODE] into [HOLD] or
[PHASE] during the SLOW OFF operation (i.e., while the amplitude is changing slowly), the
oscillator output stops at the time point of [STOP MODE] change with the amplitude at the same
time point. The following figure (Fig.4-9) shows, as an example, the waveform variation of the
oscillator output when the stop mode [STOP MODE] is changed from [ZERO] to [HOLD] during
the SLOW OFF operation.
Preset
amplitude
AC OFF
[STOP MODE] change
[ZERO] [HOLD]
AC ON
Fig. 4-9 Change of Stop mode during SLOW OFF