VIT Voltage / Current Sensor
Accurate high frequency measurements of high voltages and currents are difficult. The
limited input range of instrumentation, such as A/D converters, is often incompatible with
a wide dynamic range. Driving balanced or floating loads complicates the issue further. It
is very important to sense both voltage and current at the same point in order to get
accurate phase information. Our VIT is inserted between the output of the power amplifier
and the load.
This instrument is electrically equivalent to a wide band potential transformer and a
shielded current transformer. It can tolerate 1000 V of common mode voltage up to 200 kHz,
while maintaining the specified accuracies of magnitude and phase.
The outputs of the voltage and current channels are single ended and have a 50 ohm
source resistance. These analog monitor voltages have the same waveform as the voltage and
current under test. Their magnitudes are accurately proportional to the original
magnitudes, and the phase shifts between the voltage and current channels are matched.
Phase information will remain valid if the low level output cables are matched in length,
termination, and characteristics. These monitor signals are available at an MS type
connector on the rear, as well as at BNCs on the front panel.
VIT-10
This is a single range version which uses differential voltage sense and average
current sense. It produces a buffered, single ended low level output of 1 mV/V and 100
mV/A. All other specs are the same as the VIT-13.
VIT-13
This instrument has four levels of sensitivity of voltage and current which may be
selected locally or via isolated TTL logic. In addition, it has a current transformer in
both the high and low leg which may be selected by a front panel switch.
VIT-14
The VIT-14 is like the VIT-13 with one additional current range of 100 V/A for very low
currents.
