M2540-92000-01 A M2540 Ultrasound System Field Service Manual Page 46
Theory of Operation: Power Supply
part. Rotary and sliding knobs, rotary encoders for the knobs, the trackball assembly, and the
trackball cable are all available as separate parts.
Power Supply
The M2540A power supply is a self-contained unit that accepts AC input from 90 to 264V, at 50
or 60 Hz, and supplies 120 VAC at 60 Hz to the system’s PC, monitor, and two peripherals. It
also provides all DC power required by system components. No switch settings are required to
configure the power supply for different AC mains; the power supply automatically adjusts to use
the power connected to it. Except for the 120 VAC to the PC, all power output is activated by a
signal from the PC. The system cooling fan is the only serviceable part on the power supply. See
Figure 4-1 on page 48 for details of the power supply’s outputs. The power supply activates when
it receives an “AWAKE_N” signal, which is generated by the PC, and then sent through the BPAP
board to the power supply.
The system power supply does the following:
•Provides DC power to all system electronics through the system motherboard and the BPAP
board
•Provides DC power directly to the system cooling fan
•Provides high voltage to the distribution board for multiplexing transducers
•Isolates AC mains from secondary AC and DC circuitry
•Transforms primary voltages to secondary voltages
•Filters line AC
•Provides an isolated 120 VAC unswitched outlet to power the internal PC
•Provides three isolated 120 VAC switched outlets to power the monitor and two peripherals