Hardware; Power Supply Board; Emi Filter Stage; Power Supplies - Fujitsu MB9B100A Series User Manual

4

Hardware

This chapter describes the hardware circuitry and components of the reference board.
4.1

Power Supply Board

This board contains the EMI filter circuit and the AC-to-DC module. It will supply AC mains
and low voltage power rails to inverter board.
4.1.1

EMI filter stage

This circuit consists of the following components:
 F1-- 15A/250VAC fast acting fuse
 ZR1, ZR2 -- Across the incoming AC power supply lines to suppress high energy
transients.
 R1 -- The resistor that is used to discharge the C1 and C4 safely.
 L1, C2, and C3 -- These three components make up a common noise filter.
C2, C3 are Y capacitors.
 C1, C4 -- Film capacitors to aid in the suppression of EMI.
4.1.2

Power supplies

The power board provides the 15-volt power supply using an isolated AC-to-DC power
module (U1). The output voltage is regulated at 15-volt with a maximum output current of 1 A,
As a result maximum power is 15W. This 15-volt power rail supplies to the PFC and IPM
module directly, and three 5-volt power sources are generated. Two of them are created using
line regulators (U2, U3) and another one is created using isolated DC-to-DC module (U4).
The 5V_C is for MCU system including MCU, JTAG interface, one side of the isolation chips
and current feedback circuit of PFC stage etc and 5V_A is for another side of the isolation
chips.
4.2

In-Rush Limiter

Three high voltage electrolytic capacitors are mounted on the circuit. There will be a huge
current rush flows through the circuit when power is supplied. PTC (PTC1) connected in the
AC_L line can prevent the current rush. The relay (RL1) connected in panel with PTC is
used to short the PTC after a short period when the current get into a normal range.
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