Samsung HPR4272X/XAC, Service Manual

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Circuit Description
Samsung Electronics 13-7
5. Short Circuit and Over current Protection
An output short circuit is defined as output impedance of less than 300mohms. The power supply shall shutdown and latch off for
shorting VS DC rails to return. Shorts between main output rails and STD_5V shall not cause any damages to the power supply.
The power supply shall either shutdown and latch off until the short is removed, at which point the P/S shall recover.
The power supply shall be capable of withstanding a continuous shot-circuit to the output without damage or over stress to the unit
(components, PCB traces,connectors,etc.) under the input conditions specified in Section 3 above. Current Protection as defined
below. (Table 3)
Table 3. Over Current Protection.
6. Function of Board
①
Remote Control
Using a 250VAC/10A relay. The board makes remote control available.
②
Protection
The OCP(Over Current Protection), OVP(Over Voltage Protection), Short Circuit Protection functions are added against
system malfunction.
7. Part Block Diagram and Part Function.
①
Auxiliary Power Supply
The auxiliary power supply is a block generated power of micom for remote controlling. Once the power Plug is inserted, this
block always comes into operation, causing micom to get into the standby state for the output. Thus, this output is called the
standby voltage. And with the relay ON signal inputted through the remote controller, this block turns the mechanical switch of
relay to ON for driving the main power supply.
<Standby Flyback Pulse>
Parameter Min Unit
VS(85V) ~ A
VA(75V) ~ A
12V ~ A