Philips 27PS60S321 manual Basic IC Functionality, Degaussing

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Figure:

Figure:

Degaussing

When the set is switched on, the degaussingrelay 1515 is immediately activated as transistor 7580 is conducting.Due to the RC-time of R3580 and C2580, it will last about 3 to 4 secondsbefore transistor 7580 is switched off.

Basic IC Functionality

For a clear understanding of the Quasi-Resonantbehavior, it is possible to explain it by a simplified circuit diagram(see Figure below). In this circuit diagram, the secondary sideis transferred to the primary side and the transformer is replacedby an inductance L P .C D is the totaldrain capacitance including the resonance capacitor C R , parasitic output capacitorC OSS of the MOSFETand the winding capacitance C W ofthe transformer. The turns ratio of the transformer is representedby n (N P /N S ).

7/8/2004