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9

This section converts the AC to a stable DC voltage

1. Rectifier

Convert the AC voltage to DC
D003 : Bridge Rectifier Diode

2. AC Detection Circuit

Detect the AC voltage is of sufficient magnitude before starting the Main convertor. 
The detection is also sent to the secondary side to output the AC ALM and DC ALM
D001, D002 : rectify AC to DC for detection of voltage magnitude.
ZD001, ZD002, R006 - R078: voltage detection level setting
Q005 : turn on when the voltage level is sufficiently high
PC001: a circuit responsible for the output AC alarm signal depending Q006 behaviour.

3. Start circuit

Provide start up voltage to start Main convertor and PFC convertor
R004-R069 : drop the Main DC voltage to IC Vcc

4. Active PFC circuit

Stabilized the DC voltage and convertor the AC input current to near sine wave
Q001, Q002 : switching MOSFETs for PFC convertor
D007 : PFC boost convertor diode
D006 : PFC bypass diode
L002 : PFC boost convertor choke

5. PFC control and bias circuit

MC001 : control module with PFC convertor IC on board
Q008, Q009 : PFC switch driver transistors
D014, C006 : Bias voltage diode and capacitor

6. Inrush Current Limiter

Limit the inrush current into the power supply at AC power on
TH001: limit the inrush current at first power on
CR001 : bypass TH001 after the inrush period is over, to reduce power loss in TH001
PC005 : Quick reset of CR001 when AC is off. 

7. C007, C008 : DC smoothing capacitors (Bulk cap)

AC INPUT

Q005

PC001

AC Alarm

Voltage Level - HIGH

ON

ON

L

Voltage Level - LOW

OFF

OFF

H

10

This section converts the high DC voltage in the primary side to DC low voltage (41V) at the secondary side

1. Isolation switching transformer.

T001: provide isolation of the hazardous high voltage Primary to the SELV secondary.

2. Main switching MOSFET

Q003, Q006 : Main switching MOSFETs 

3. Main switch control circuit

Provide the switching PWM control to ensure regulated DC 41V output
IC001 : PWM IC
PC004 : photocoupler provides feedback from secondary side to primary side.
Peripheral circuit provides control and bias voltage for PWM Vcc and PFC IC Vcc
TS001 : shut down the PWM during abnormal over heating on the Primary side
PC002 : shutdown the PWM during abnormal output voltages and over current of 15V
PC003 : shutdown the PWM when the Battery reverse connection is detected.

4. Convertor 41V Output circuit

Convert the switching DC voltage to regulated DC voltage
D104, D105 : Rectifies the switched transformer secondary to DC voltage
C107, C112 : DC output smoothing capacitors
C115, L109 : Ripple filter components

11

15V Output circuit converts the 41V or the Battery back up voltage (during back up mode) to a regulated 15V output by DC-DC 

switching PWM

1. Q201: DC-DC switching MOSFET

D202: Flywheel diode
L202 : DC-DC choke
C204 : DC output smoothing capacitor
Peripheral circuit provides ripple reduction and voltage sensing and feedback

2. DC-DC switching IC and control circuit

MC201 provides the control IC for switching and voltage control

15VP Output circuit converts the 41V or the Battery back up voltage (during back up mode) to a  regulated 15V output by DC-

DC switching PWM

1. Q302, Q303: DC-DC switching MOSFETs (parallel operation)

D302: Flywheel diode
L302 : DC-DC choke
C305, C306 : DC output smoothing capacitor
Peripheral circuit provide ripple reduction and voltage sensing and feedback

2. DC-DC switching IC and control circuit

MC301 provides the control IC for switching and voltage control

12

30V Output circuit converts the 41V or the Battery back up voltage (during back up mode) to a regulated 30V output by DC-DC 

switching PWM

1. Q502 : DC-DC switching MOSFET

D503: Flywheel diode
L502 : DC-DC choke
C506 : DC output smoothing capacitor
Peripheral circuit provide ripple reduction and voltage sensing and feedback

2. DC-DC switching IC and control circuit

IC551 provides the control IC for switching and voltage control

41V Output circuit converts the 41V convertor output or the Battery back up voltage (during back up mode) to a ON/OFF 

switched 41V output voltage  

1. Q106 : DC output switch MOSFET

Peripheral circuit provide ripple reduction and OCP

2. Short circuit Protection control circuit

Allow the 41V output to switch into Hiccup mode during short circuit
R101 : Output current sensing resistor
IC101 : Over current sensing comparator IC
Q104-Q108 : peripheral circuit to activate the On/Off of Q106 during output short circuit