KEPCO MBT Series - Manual (Page 116)

4-10
MBTSVC111609
4.2 MBT SERIES BLOCK DIAGRAM CIRCUIT DESCRIPTION
Figure 4-4 is a block diagram of the MBT Series Power Supply; Figure 4-5 provides the location
of internal power supply components.
Source power is routed through the rear panel AC INPUT connector A6J1, front panel POWER
circuit breaker A6CB1 and rear panel AC INPUT SELECTOR switch A6S1 and distributed via
terminal block A6TB1 to the cooling fan A6B1, the main power transformer A6T1, and Relays
and Flag Board A2. For MG and MGR option units, source power is also applied to an integral
FMP-5K a-c to d-c power module used to provide V
CC
for digital logic on Single Board Com-
puter (SBC) Board A13 and Interface Board A14. The AC INPUT SELECTOR allows the MBT to
operate with either 115V a-c or 230V a-c source power.
Main transformer A6T1, bridge rectifier A6CR1 and main filter elements A6C1 and A6C2 pro-
vide d-c voltage to heat sink assembly A7. The heat sink assembly provide the current-amplified
output voltage to the output terminals at the rear panel via the current sensing resistor A10R1
on Board A10 (and, for MR and MGR option units, via output/polarity reversal relays located on
a chassis-mounted bracket). The heat sink also provides thermostat outputs to terminal block
A6TB1 and to Mother Board A5 which interconnects Auxiliary Power Supply Board A4, Relays
and Flags Board A2, Analog Control Board A1, Digital Control Board A3, and Front Panel Board
A8.
Analog Control Board A1 compares the Reference Voltages derived from Digital Control Board
A3 with the feedback signals from the Power Section. Analog Control Board A1 then provides
control signals for the Power Section which determine the output of the power supply. This
board also contains some of the protection and shutdown circuits (see PAR. 4.3.1).