| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an isolated transformer type constant current power supply device which is a power supply device capable of adjusting an output current with a phase control type input voltage converter and which has an error amplifier for detecting an output current on the secondary side and controls an oscillation frequency or duty on the primary control section because the power device of this type has a problem that an output current varies when a commercial input voltage varies, with the input voltage converter provided at the pre-stage. <P>SOLUTION: An input voltage correction circuit which operates only when an input voltage converter is used is provided and, in use of the input voltage converter, is configured so that an output current is not changed by applying secondary reference voltage correction to an output current variation due to a variation in an input voltage. In addition, an input voltage is monitored in a pseudo manner with a secondary voltage of an isolated transformer. <P>COPYRIGHT: (C)2013,JPO&INPIT |
