| 摘要 |
PROBLEM TO BE SOLVED: To reduce power loss in a load current detection circuit in standby by providing a path for supplying a larger current than a prescribed value for connecting to a specific output line other than current being supplied from the secondary-side coil winding of a transformer, and by comparing the voltage of the connection point with a reference voltage for detecting a load current. SOLUTION: In a two-output power-supply unit, a first output voltage VAO is supplied to the power supply of the drive system of body equipment, and a second output voltage VBO is supplied to the power supply of a logic circuit system, that consumes power even at standby. In this case, a load current detection circuit 3 consisting of a resistor 6 and a comparator 15 is composed, and the resistance value of the resistor is set to a value that can supply a large current than a load current on standby, thus supplying the load current of second of second output, by adding current flowing via a diode 8 to that flowing via the resistor 6 in a steady state, supplying the load current of the second output merely by having current flow via the resistor 6 on standby, and hence reducing the power loss of the load current detection circuit 3 on standby. |
