| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption in a waiting state. SOLUTION: This power supply device of an electronic apparatus has a transformer 10, which has a primary winding N1 with a changeover tap TC and secondary windings N2a and N2b and a changeover control means, which changes the number of turns of the primary winding N1 of the transformer 10 to control the voltages induced in the secondary windings N2a and N2b. The voltages induced in the secondary windings of the transformer 10 are used for the operations of the electronic apparatus and the changeover conter means. The changeover control means controls the input voltage, so as to have it applied to the winding between both the terminals of the primary winding N1 in the waiting state of the electronic apparatus and so as to have it applied to the winding between one of the terminal and the changeover tap TC of the primary winding N1, when the operation of the electronic circuit is started and the electronic apparatus is driven by the voltage induced in the secondary winding of the transformer. With this constitution, the voltage induced in the secondary winding in the waiting state of the electronic apparatus becomes lower than the voltage induced in the operation state of the electronic apparatus, so that power consumption in the waiting state can be reduced. |
