McCain FleX M73101R, User Manual, Page: 19 / 142

12
Figure 7: Bottom Module.
The sub-assemblies installed onto the bottom panel are described below:
2.5.3.1 Power Supply Sub-Assembly (M45891).
This sub-assembly consists of a switching power supply module with a large can back up capacitor. It
provides the DC voltages to the Control Signals board (M58574A) and receives the AC power from such
board. The DC voltages provided are +24VDC, +12VDC and +5VDC.
2.5.3.2 Control Signals Board Sub-Assembly (M58574A).
This board generates the POWERDOWN, POWERUP and LINESYNC signals and along with the DC
voltages received from the power supply assembly. It also sends the signals and voltages to the other
sub-assemblies through the corresponding harness.
The board also has a circuit to define the trip and recover window for the AC power input; this is a factory
set adjustment and should not be changed. The default is: 85VAC for power down and 90VAC for power
up.
This sub-assembly contains the below circuits and connectors:

A five positions header (AC INPUT) for receiving the AC power input.

A two positions header (FUSE/SWITCH) for connecting the AC+ line to the fuse and switch
located on the front panel.

A three positions header (AC OUTPUT) for providing the AC power to the power supply sub-
assembly (M45891).

A five positions header (DC INPUT) for receiving de DC power from the power supply sub-
assembly (M45891).

An eight positions header (DC FOR HOST) for providing the +5VDC power, POWERDOWN,
POWERUP and LINESYNC signals to the hostboard (M58570A).

A three positions header (DC FOR FIO) for providing the +5VDC and +12VDC power to the Field
I/O board (M58573A).