GENERAL INFORMATION
AMPLITUDE CONTROL
The AVO-6HF-B consists of two parts, the mainframe and the output module. The
mainframe is a voltage pulser, which generates up to 250V (V
OUT
).
The fan-cooled output module contains a 50Ω series resistance (capable of dissipating
up to 50 Watts of average power), and packaged diodes may be soldered to the output
terminals of this module. The diode load is connected in series with the internal
resistance, so that the current through the diode is normally given by:
I
DIODE
= (V
OUT
– V
DIODE
) / 50Ω
where V
DIODE
is the voltage drop across the diode. These values must be selected such
that I
DIODE
never exceeds 5A.
The functional equivalent circuit of the output module is shown below:
Output Module Functional Equivalent Circuit
An additional resistance (R
MON
) can be placed in series with the diode load, for current
monitoring purposes. In this case, the diode current is given by:
I
DIODE
= (V
OUT
– V
DIODE
) / (50Ω + R
MON
)
Alternatively, a fast current probe may be used to monitor the current waveform.
Factory testing is conducted using a Tektronix CT2 or Pearson 2878 current
transformer. (This technique tends to introduce less waveform distortion than the
sensing resistor method. However, AC-couped current probes such as the CT2 will not
be able to operate at pulse widths of more than a few microseconds. The 2878 does
operate to 50 us, the maximum pulse width of the AVO-6HF-B.)
20
50 Ω
10 kΩ
IOUT,
5A MAX.
OUTPUT MODULE
INPUT FROM
MAINFRAME
(0 TO 250V)
CONTROL
CABLE FROM
MAINFRAME
FAN &
THERMISTOR
Diode (device under test),
oriented for positive operation.
Reverse for negative operation.
Содержание AVO-6HF-B
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