Matsushita Electric Industrial Co., Ltd.

Takuya Nishide

Takatsugu Kurata

Shigeru Sakaguchi

A power supply unit having: transformer ( ) with primary winding ( ) connected to D.C. power supply ( ); switching element ( ) connected to the primary winding ( ) of the transformer ( ); forward controller ( ) for controlling the switching element ( ); rectifier element ( ), choke coil ( ), switching element ( ) and smoothing circuit ( ), all connected in series between secondary winding of the transformers ( ) and output terminal ( ); rectifier element ( ) connected in parallel with the rectifier element ( ) and the secondary winding; and switching element ( ) and smoothing circuit ( ) connected in series between an output terminal of the rectifier elements ( ) and output terminal . The forward controller ( ) controls the switching element ( ) responsive to an output voltage of the smoothing circuit ( ). Divider control circuit ( ) controls the switching element ( ) responsive to an output voltage of the smoothing circuit ( ).

Power supply unit having reduced size and weight and an electronic apparatus using the same

A television receiver in which addresses are assigned to functional boards provided with different functional circuits such as teletext demodulators and satellite broadcast wave receivers, to identify each functional circuit, address data for specifying a functional circuit is sent out from a microcomputer, and a response signal from the functional circuit is read out by the microcomputer to judge the presence or absence of the functional board having the specified functional circuit, thereby automatically determining whether the functional board is to be controlled.

Television receiver having a microcomputer for determining the presence

A field discrimination circuit for use in a television receiver, which includes a shift register for shifting an input vertical synchronizing signal so as to produce n (n.gtoreq.6) pseudo vertical synchronizing signals having the same phase difference, a selector for selecting one of the n pseudo vertical synchronizing signals and delivering the selectd pseudo vertical synchronizing signal as a reference vertical synchronizing signal, a latch circuit for detecting input timing of the reference vertical synchronizing signal into one of n time sections obtained by dividing one horizontal scanning period by n, to thereby generate a latch output signal, and a decoder for effecting field discrimination on the basis of the latch output signal and generating a field discrimination signal.

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Mie, Japan

Takuya Nishide