| 摘要 |
PURPOSE: To obtain a DC power-supply apparatus in which the constitution of a peripheral circuit related to a plurality of input signals, for output activation, to a control IC is simplified by a method wherein an output activation signal used to activate the output of the control IC is input to a plurality of input terminals and an OR circuit which computes a logical add is connected to the plurality of input terminals. CONSTITUTION: A start-up circuit 27 which generates a trigger signal only in a drive start is connected to an input terminal T14 installed at a control IC 26, and another input terminal T15 is connected to a secondary-side coil L2 at a current transformer. Then, a two-input OR circuit 40 is connected to the input terminals T14, T15, and signals for output activation are unified. The output end of the OR circuit 40 leads to one input end of a NAND circuit 41, and it leads to one input end of an AND circuit 43 via a NOT circuit 42. The output end of the AND circuit 43 leads to a driver 44, and its output end leads to the gate of a MOSFET 34 via an external terminal T2. Consequently, a DC power-supply apparatus can be designed easily. |
