Bally 5000 Plus, Manual

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11.
Appendices
Appendix 5:
POWER SUPPLY
POWER SUPPLY
A power supply's job is to deliver a constant voltage by compensating for variations in the
input power and changing load requirements, to yield an output free of ripples or spikes
that's electrically isolated from the line voltage.
The V -5000 uses a 125 watt switching regulator power supply to develop + 5V DC, + 12V
DC, - 12V DC, and + 24V DC. It utilizes pulse- width-modulation technology in a
configuration known as a flyback converter. This type of supply has an efficiency of 65% to
S5%, depending upon load conditions.
The supply operates over an AC voltage range of 90 to 130 V AC at an input frequency of
47 to 440Hz. The minimum and maximum currents for each output are as follows:
V Nominal I Minimum I Maximum*
+ 5V 1A SA
+ 1 2V O.SA 4A
-12V O.OA O.SA
24V 1A 4A
*
Maximum power output limited to 130 watts.
A flyback converter is best suited to low power applications (50 to 150 watts). The V-5000
power supply can be divided into 5 main sections. They are the input rectifier, power
converter, output rectifiers, protection circuits, and power fail detection.
1 .
The Input Rectifier
1 15 V AC is applied to the power supply at connector P I. Pin 1 is connected to AC hot, pin
3 to AC neutral, and Pin 2 to earth ground. A fuse (F 1) is incorporated in the live side.
MOV1, C1, C2, C3, C4 and L1 comprise an input filter for conducted EM!. TH 1 and TH2
are thermistors which limit the inrush current to the supply at turn-on. The AC input is
rectified by voltage doubler DB1 and filtered by capacitors C7 and CS. Components L2,
L3,
C5, C6, C7 and CS comprise a second EMI filter. The output of inductor
L3
forms the
ground reference for the power converter section of the design. The output of inductor L2
provides DC power to the converter section. At this point, approximately 300 volts DC is
present at L2.
11-7