Mindray DC-8 EXP Service Manual

4-22 Product Principle
Front-end power
main board
FLYBACK
converter *4
PHV *4
A±95V
+19VCC
BOOST converter
Control & protect
EDC_+12V
A+5V7
A+4V2
A+3V3
A+1V8
A-5V7
A-12V
FLYBACK
converter
PHV feedback
Current-limit
circuit
A+2V5
Front-end power
auxiliary board
I/O
Back-
end
mother
board
Communic
ation
mother
board
BUCK converter
*5
BUCK-BOOST *2
Fig 4-27 Schematic Diagram of the Front-end Power Board
4.8.4.1 Front-end Power Main Board
Function description:
 The front-end power main board mainly generates the ultrasound transmission power,
including 4 channels adjustable voltages PHV, 2 channel fixed voltages A±95V, 1 channel
+19VCC output ,and transfers all the powers generated by the power auxiliary board.
 PHV control and feedback circuit mainly include three parts: ARM, ADC sampling and
operation & amplification. Main system CPU module can directly determine PHV voltage
and read the output voltages of each power (including the outputs from front-end power
auxiliary board).
Power sequence:
 After each circuit module on the board is started, PHV and ±HV are still kept closed, PHV
and ±HV will be started only if the IC received the commands from CPU module, PHV
output voltage is determined by the commend of CPU module.
4.8.4.2 Front-end Power Auxiliary Board
Function description:
 Front-end power auxiliary board transfers +12V into +5.7V, +4.2V, +3.3V, +2.5V, +1.8V,
-5.7V, -12V, etc., which will power the front-end circuit. Current from +5.7V, +4.2V, +1.8V
are great, so bi-channel intervening parallel BUCK convertor is adopted, +3.3V, +2.5V
current output is small, they use one IC together. -5.7V, -12V use BUCK-BOOST
topological circuit.
 The power auxiliary board is directly inserted on the power main board, but there is no
electrical control. Only the output and input of the power auxiliary board are transferred
through the power main board, meanwhile, the power main board will sample all the
voltages and then report them to the main system.
Power sequence:
 Each circuit unit is independently controlled, they are started when the power is input, no
confirmed order.

Mindray DC-8 EXP Specifications

General

Brand	Mindray
Model	DC-8 EXP
Category	Medical Equipment
Language	English