Harris Platinum Z16HD+, Предварительное руководство

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9/15/06 888-2586-001 4-23
WARNING: Disconnect primary power prior to servicing.
Section 4 Overall System Theory
Platinum Z16HD+
Figure 4-7 Power Supply Locations, Top View
Figure 4-8 shows a simplified diagram of one of the 3-Phase PA power supply
transformers (for the 3 phase, 4 wire connection, the primary would be re-configured as
WYE). Each transformer has a 3 wire extended DELTA or extended WYE primary
(depending on your AC input configuration) and two secondaries labeled A and B
which are always WYE wound, with the center tap being the output. The outputs of the
2 secondaries are combined through chokes and filtered by a single 120,000uF
capacitor. The combination of the extended primary windings and the dual secondaries
(each at a different phase angle) results in an output ripple frequency of 600/720Hz for
50/60Hz input. Each of the secondary windings has 4 possible voltage taps, each of
which are connected through an SCR to ground. The SCRs act as tap switches,
activating the tap which gives the appropriate DC voltage output, as rectifiers and as a
way of turning the supply on and off. This gives a total of 12 SCRs per secondary (4 per
winding), but only 3 SCRs (per secondary) will be activated at any one time providing
the ability to regulate the output DC voltage by changing the transformer turns ratio.
The 4 secondary taps basically change the primary to secondary turns ratio allowing DC
outputs of 48, 50, 52 and 54Vdc. The tap switching is controlled by the Power Supply
Controller boards. There are 4 separate power supplies designated PS1, PS2, PS3 and
PS4. Each power supply provides power for 8 of the 32 PAs. PS1 and PS2 supply power
for Z-Planes A and B (and IPA_AB) while PS3 and PS4 power the PAs on Z-Planes C
and D (and IPA_CD).