AVTECH ELECTROSYSTEMS AVRQ-4-B, Instructions Manual

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FRONT PANEL CONTROLS (UNITS WITHOUT -FPD OPTION)
1. POWER Switch . This is the main power switch. When turning the instrument on,
there is normally a delay of 10 seconds before anything is shown on the main display,
as the internal operating system boots up.
If the main menu does not appear after 30 seconds, turn off the instrument and leave it
off for at least 60 seconds before applying power again.
2. OVERLOAD Indicator . When the instrument is powered, this indicator is normally
green, indicating normal operation. If this indicator is yellow, an internal automatic
overload protection circuit has been tripped. If the unit is overloaded (by operating at an
exceedingly high duty cycle or by operating into a very low impedance), the protective
circuit will disable the output of the instrument and turn the indicator light yellow. The
light will stay yellow (i.e. output disabled) for about 5 seconds after which the instrument
will attempt to re-enable the output (i.e. light green) for about 1 second. If the overload
condition persists, the output will be disabled again (i.e. light yellow) for another 5
seconds. If the overload condition has been removed, the instrument will resume
normal operation.
This overload indicator may flash yellow briefly at start-up. This is not a cause for
concern.
3. SYNC OUT . This connector supplies a SYNC output that can be used to trigger
other equipment, particularly oscilloscopes. This signal leads (or lags) the main output
by a duration set by the "DELAY" controls and has an approximate amplitude of +3
Volts to R
L
> 1 kΩ with a pulse width of approximately 100 ns.
4. LIQUID CRYSTAL DISPLAY (LCD) . This LCD is used in conjunction with the
keypad to change the instrument settings. Normally, the main menu is displayed, which
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