| 摘要 |
<p>A flyback-type switching power supply circuit provided with a transformer including a primary coil and a secondary coil, and a switching element connected to the primary coil, wherein the flyback-type switching power supply circuit is provided with: a multiplying circuit for multiplying a first value obtained by multiplying the on-duty ratio of a secondary current flowing to the secondary coil by a predetermined first constant, and a second value obtained by multiplying the peak value of a primary current flowing to the primary coil by a predetermined second constant; and a switching control circuit for controlling switching of the switching element so that the result of multiplication by the multiplying circuit and a third value obtained by multiplying a reference voltage by a predetermined third constant match; and the flyback-type switching power supply circuit is configured so that at least one of the first constant, the second constant, and the third constant is variable by an external signal.</p> |
