User and Programming Manual
XDS Series
49
The secondary arrangement of the power transformer depends on the output voltage. High voltage
output models used a full-bridge arrangement. Low voltage output models use a center-tapped
circuit. The latter is shown in Figure 6-3. The snubber board (A5) holds RC snubbers to control
voltage spikes on the rectifiers. Circuit arrangement on this board varies per model output voltage.
Secondary return current is monitored with a shunt resistor and represents the current in the output
inductor. This current sense signal is used by the PWM controller for stability and protection.
The rectified output passes through a large filter inductor, to an electrolytic capacitor, through smaller
inductors, and to a final electrolytic capacitor. A shunt in the output return lead senses output current
for measurement and current programming. The output filter board (A6) mounts to the electrolytic
capacitors. This board holds small filter capacitors and remote voltage sense circuitry. The voltage
sense signals are fed back to the CPU controller assembly through the DC module amplifier board.
A thermal switch on the DC module heat sink opens if the monitored temperature is too high. This
disables the DC module and is reported by the CPU controller.
A discharge circuit on the DC module amplifier board sinks current from the output electrolytic
capacitors to quickly remove charge from the output. The level of discharge depends on the model
output voltage and amount of external capacitance added by the user.
Each power module is made up of three PCB's, A4 through A6.
6.4.1
Amplifier Module (A4)
The amplifier module board is located perpendicular to the base heat sink of each power module.
This board contains the switching control logic and power devices for both AC-DC and DC-DC stages
of the power module.
6.4.2
Snubber Board (A5)
The snubber board is a small board located below the input electrolytic caps on the power board. The
snubber board connects directly to the power diodes, which mount on an isolated mounting plate
between the transformer and the output inductor.
6.4.3
Output Filer Board (A6)
The output filter board is located in the back of each power module, directly above the output
electrolytic caps. One of the three power modules has an output filter board with external sense
connector. (5005-700-1) This module is always on the far right of the chassis. The other two power
modules (if present) have an output filter board without sense connections. (5005-700-2).
Содержание XDS 100-100
Страница 4: ...User and Programming Manual 4 XDS Series Electrical Safety Symbols Used in This Manual ...
Страница 27: ...User and Programming Manual XDS Series 27 Figure 3 5 Outline Drawing XDS DC Supply ...
Страница 41: ...User and Programming Manual XDS Series 41 Figure 5 4 Parallel Cable Interconnect Accessory ...
Страница 45: ...User and Programming Manual XDS Series 45 Figure 6 1 DC Power Supply Block Diagram IF option shown ...
Страница 69: ...User and Programming Manual XDS Series 69 Figure 8 3 Replaceable Fuse Locations ...