AR 350A400, Operating And Service Manual

Page: 43 / 52

Model 350A400
Rev B 27
3.3 POWER SUPPLIES (PS1, PS2, PS3)
Power supply PS1 supplies a +5VDC housekeeping supply for the control system assemblies A12
Control/Fault Board and A14 Interface Board.
PS1 also supplies -15 VDC at 2.5 amps. PS1 is a switching supply that automatically sets the AC input
circuits to the correct connections for the line voltage 100-240 VAC input ranges 47-440 Hz.
The -15 VDC at 2.5 amp power supply is fed to the A1 Pre-Amp, and A2 driver and A4 – A7 Power
Modules.
The +24 VDC at 7.5 amps power supply is fed to the B1, B2, B3 and B4 fan assemblies.
Power Supply PS2 is a single output supply which pr40VDC to the A2 driver and A6 and A7 power
modules. Primary AC circuit protection is provided by the circuit breaker in the Power Entry Module.
Power Supply PS3 is a single output supply which pr40VDC to the A4 and A5 power modules, and
the A9 regulator assembly. Primary AC circuit protection is provided by the circuit breaker in the Power
Entry Module.
3.4 CONTROL SYSTEM
3.4.1 A12 Control/Fault Board (Schematic #10042218)
The A12 Control/Fault board consists of one 16-bit microcontrollers and several other ICs that monitor and
indicate the status of the amplifier. Power is supplied using only a single 5-volt power supply. The board
offers the following:
Feature Quantity
Open drain outputs 4
Digital outputs 6
Digital inputs (5-volt tolerant) 24
Analog outputs 2
2-channel encoder input 1
Inputs for a keypad 6
Display connectors 1
Serial communication jacks 2
3.4.2 A14 Interface Board (Schematic #10020073)