B. Braun Vista basic - Voltage Supply

System Overview
Voltage Supply The voltage supply is generated either directly from mains, via the
FM plug (14 V connection to the fluid manager system), or via the
MFC connector (11 to 16 V) and as an internal supply via the in-
ternal 7.2 V NiCD battery. The mains module is available in three
versions: 230 V, 220 / 230 / 240 V and 100 / 110 / 120 V. The rated
voltage has a tolerance of + 10% to — 15 %.
Avoltage of 11 Vto 18 Vis available after transformation and rec-
tification. This voltage is fed to the battery charge circuit and the
unit supply. This is also valid for an external 12 V supply from the
MFC or FM plug. The FET V10 switches between the external and
the internal voltage supply. The transistor VIOb works as an ON/
OFF switch for the operating voltages UBS, UMOT and +5V. The
+5V supplies the complete electronics including the double chan-
nel microprocessor system. A window comparator constantly
monitors the +5V for undervoltage or overvoltage. The function is
checked during switch- on. The operating voltage UBS supplies the
stepper motor and the UMOT, the stepper motor drive.
The transistor V47 switches the operating voltage UMOT. In case
of an alarm the motor is switched off by V47. Additionally the
switching function of the transistor is checked during the switch-
on test.
The circuit has two separate assembly groups with separate sup-
ply voltages UBA and UBB. The ON/OFF circuit has a retriggerable
delay switch: off. A follow-up charging circuit drives the transis-
tor V10b.
The alarm logic (operating voltage UBB) is an RS latch. This is set
when the unit is running and activates the alarm circuit. The
alarm buzzer and drive are also driven by UBB. The ON/OFF circuit
is activated and the voltage supply is switched on by pressing the
ON/OFF key. The alarm latch is reset simultaneously. A function
test of the voltage monitoring, motor circuit and alarm activation
is performed, The voltage supply is maintained by cyclic self-hold-
ing pulses fed to the logic. The alarm latch is also activated.
Vista basic 950971 Rev A (5/04) 1-5