| 摘要 |
PROBLEM TO BE SOLVED: To enable easily switching over power source voltages with a simple constitution, when a plurality of transformers are used. SOLUTION: This power source unit is equipped with a tap in the primary winding 22 of a main transformer 20. According to a power source voltage, primary winding 21, 22 of the transformer 20 and primary windings 31, 32 of a subtransformer 30 are switched over with a voltage selector 40, in such a manner that parallel connection or series connection is selected, or windings between terminals 22b and 22c of the primary windings 21 and 22 of the transformer 20 are made into a series connection, and a winding between terminals 22a and 22b of the primary winding 22 of the transformer 20 and the primary windings 31 and 32 of the subtransformer 30 are made a series connection. When the electronic equipment is in a standby state, power supply to the primary windings 21, 22 of the transformer 20 is stopped. When the electronic equipment is operated, power is supplied to the primary windings 21, 22 of the transformer 20. |
