Abstract: A power supply unit for an electronic device comprises a three-terminal regulator in a high voltage connection line between a high voltage terminal of a DC power supply circuit and a microcomputer for reducing voltage from the high voltage terminal to a lower first voltage. A low voltage connection line between a low voltage terminal of the power supply circuit and the microcomputer is connected to the high voltage connection line at a connection point on output side of the regulator. In standby mode, voltage from the high voltage terminal, set higher than the first voltage, is reduced by the regulator to the first voltage and supplied to the microcomputer. In power-on mode, voltage from the low voltage terminal, set higher than the first voltage, is applied to the connection point so as to inactivate the regulator and supply the voltage from the low voltage terminal to the microcomputer.

Abstract: A liquid crystal television receiver reduces the brightness of a backlight which generates light to be passed through a liquid crystal panel and thereby forms an image, to a brightness invisible to human eyes. After the brightness is reduced, a panel signal to the liquid crystal panel is controlled to change from the ON state to the OFF state. After the panel signal is controlled to change to the OFF state, the backlight is controlled to change from the ON state to the OFF state. In this way, the backlight of the liquid crystal panel is controlled so that disturbance in image, which occurs when the panel signal to the liquid crystal panel is changed from the ON state to the OFF state, can easily be prevented from being seen by users.

Abstract: The present invention aims to obtain a stable output voltage without requiring an extra circuit by suppressing influence of noise of the primary winding and voltage induction by leakage inductance. In a transformer 3 used in a multi-output switching power supply, a secondary winding S1 for outputting a voltage to be fed back to the primary side out of the secondary windings S2 to Sn winded on a bobbin 3a is divided into a first layer S1a and a second layer S1b, a secondary winding S2 to Sn for outputting a voltage not fed back to the primary side is winded between the first layer S1a and the second layer S1b, and the first layer S1a and the second layer S1b is regular winded.