Figure 3-3 Aspen System Power On/Off Sequence; Power Up Sequence - Acuson Corporation Aspen Service Manual

Chapter 3 - Power Subsystem
Power Up Sequence
When the system is plugged into an AC power outlet and the main
circuit breaker is switched on, a standby power is supplied to a
circuit located on the lOB board which monitors the system's power
On/Off switch. Pressing the momentary On/Off power switch on
the Aspen system sends a power-on request to the lOB. The lOB
latches the power-on request, and sends it to the Main Power
Supply. The Main Power Supply then turns on all system DC power
which allows the system to power up. The
12V
peripheral power
comes up in approximately 150 miliseconds and closes the relay in
the Isolation Transformer Box, applying AC power to the primary
of the Isolation Transformer which in tum brings up the monitor,
PPS and peripherals that are connected to the accessory outlets.
During the off-to-on transition phase of the power supplies, before
power has stabilized, a reset signal, generated by the lOB, is applied
to the Scanner and DIMAQ wwigitation.
After the power has stabilizednhe system reset is removed by the
lOB. At this point, the system begins its boot sequence. Refer to
Figure 3-3 for a simplified diagram of this operation.
System
Controller
REQUEST POWER ON
Y (STANDBY)
PWR ON REQUEST
Y(STANDBYI
U.I.
L _
1----------_
DC
POWER
MAIN
CIRCUIT
BREAKER
MAIN
POWER SUPPLY
ALL SYSTEM DC POWER
AC POWER INPUT
Figure 3-3 Aspen System Power On/Off Sequence
3-8
Acuson Aspen Ultrasound System 1096