Section 1- General Information; Introduction; Description - Tektronix 067-0883-99 Instruction Manual

UNIVERSAL LOAD UNIT
SECTION 1
GENERAL INFORMATION
Introduction
The Universal Load Unit (ULU) is a bench top testing device that will
provide a convenient method of performance checking the internal power
supplies in several Tektronix instruments. It may be used to test and
verify proper voltage regulation of single and multiple output supplies
under variable load conditions. The ULU is used in conjunction with
Programming plug-in modules that are temporarily installed, one at a time,
into the Load Unit through its front panel.
Description
The Universal Load Unit includes twelve active load cells (channels)
and one passive channel through which up to thirteen output voltage levels
can be concurrently loaded. The current through any active channel is
varied by an internal pulse generator to provide transient response testing.
The voltage or current in a selected channel may be displayed on the Load
Units front panel digital multi-meter. Also, each channel is monitored for
an out-of-tolerance condition.as indicated by one of thirteen comparator-
driven, front panel LED's. The thirteen position CHANNEL SELECTOR switch
is used to connect the ULU controls and output monitoring circuits to each
of the 12 active cells. As selected, each active load cell or channel can
be set up to provide a .resistive load or a constant current load for a
given power supply output. Each active load cell includes a current sensing
resistor, current amplifier and cell protection circuitry. Each programming/load
module supports 12 active and 1 passive channel. All twelve active channels
can be programmed by the installation of six user selected resistors per
channel (See Appendix A). The resistors select high or .low current levels
and equivalent load resistances and establish nominal voltages and tolerance
limits for the ULU's comparator circuitry. The passive channel
(13)
is
programmed with two fixed resistors.
·Each programming module is used to test the internal power supplies
in a specific Tektronix instrument and will be separately part numbered.
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