Avtech AVR-8F-B-P-ADB1A, Instructions Manual

Page: 26 / 43

OPERATIONAL CHECK
This section describes a sequence to confirm the basic operation of the instrument. It
should be performed after receiving the instrument. It is a useful learning exercise as
well.
Before proceeding with this procedure, finish read this instruction manual thoroughly.
Then read the “Local Control” section of the “Programming Manual for -B Instruments”
thoroughly. The “Local Control” section describes the front panel controls used in this
operational check - in particular, the MOVE, CHANGE, and ADJUST controls.
1. Connect a cable from the SYNC OUT connector to the TRIG input of an
oscilloscope. Connect a 200Ω (or higher) load to the OUT connector and place the
scope probe across this load. The load resistor and the scope probe must have a
voltage rating of at least 1000V and an average power rating of 5 Watts. The power
dissipated in the resistor is given by
P = (V 2 / R) × (PW / T) = (V 2 / R) × PW × f
where “V” is the output voltage, “R” is the load resistance, “PW” is the pulse width,
and “T” is the pulse period (1/frequency), and “f” is the frequency. Factory tests are
conducted using a series-parallel combination resistors to make a high-voltage,
high-power, low-inductance composite load. Fan cooling the resistors allows for
slightly higher power dissipation. (Ohmite “OY” ceramic composition resistors -
http://www.ohmite.com - are recommended for such applications. These resistors
are readily available from http://www.digi-key.com/ and other distributors.)
2. Set the oscilloscope to trigger externally with the vertical setting at 200 Volts/div
and the horizontal setting at 1 us/div. Be sure that your oscilloscope and probe
26
AVTECH
PULSER
MAIN OUTPUT
CONNECTOR
SYNC
OUTPUT
AC
POWER
ALL CABLES: 50 OHM COAXIAL
REAL-TIME
OSCILLOSCOPE
CHANNEL A
TRIG
INPUT
SCOPE
PROBE
TEST
LOAD