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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, R011 - R064: voltage detection level setting
Q006 : turn on when the voltage level is sufficiently high

3. Start circuit

Provide start up voltage to start Main convertor and PFC convertor
R004, R065 : 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
Q007, Q009 : PFC switch driver transistors
C006 : Bias voltage 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)

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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, Q008 : 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
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 : Rectifies the switched transformer secondary to DC voltage
C108, C109 : DC output smoothing capacitors

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, Q202: DC-DC switching MOSFETs (parallel operation)

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

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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. Q303 : DC output switch MOSFET

Allows the 15Vp output to be switched On and Off 
Peripheral circuit provides ripple reduction and OCP

2. Short circuit Protection control circuit

Allow the 15Vp output to switch into Hiccup mode during a output short circuit
R301 : Output current sensing resistor
IC301 : Over current sensing comparator IC
D302, Q301, Q302 : peripheral circuit to activate the On/Off of Q303 during output short circuit

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

MC501 provides the control IC for switching and voltage control

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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

C115, L109 : Peripheral circuit provide ripple reduction

2. Short circuit Protection control circuit

Allow the 41V output to switch into Hiccup mode during short circuit
R101 : Output current sensing resistor
Q104-Q109 : peripheral circuit to activate the On/Off of Q106 during output short circuit

This section generates the Alarm signal such as AC ALM, DC ALM

1. AC ALM Signal Output

The detection of AC is done on the Primary and the information is transmitted to the secondary side via PC001. 
AC ALM is generated by the IC133 by monitoring the condition of the transistor side of PC001.
IC133 : Voltage monitoring IC with delay.
Q134 : Open Collector Output buffer transistor for AC ALM

2. DC ALM Signal Output

The detection of each of the output voltage of 15VP, 30V and 41V. 
DC ALM is sent out when any of the output voltages drop below the pre-set value or when AC ALM is activated.
However, when a working Battery is connected to CN604 DC ALM is not sent out during the period AC ALM is activated while 
the DC output voltages are within the pre-set value.
SW601: Battery Backup On/Off control
Q165, D135, Q133: Negate the sending out of DC ALM during AC fail and Battery backup is activated.
IC131, IC132 : Comparator IC for detecting the status of each output.
Q130: Open Collector output buffer transistor for DC ALM