| 摘要 |
PROBLEM TO BE SOLVED: To provide a power feeding circuit that can superimpose an AC signal with high amplitude on a detection signal without the need for a large sized circuit. SOLUTION: This circuit is provided with an AC signal source S101 that outputs an AC signal with a frequency band not overlapped with a pass band of a low pass filter circuit (consisting of a resistor R101 and a capacitor C101), an inverted voltage sum circuit (consisting of resistors R102-R104 and an operational amplifier A101) that superimposes the AC signal from the AC signal source S101 on a detection signal from a voltage current detection circuit DET via the low pass filter circuit and gives the resulting signal to a switching regulator control circuit CONT that conducts negative feedback control, and switches SW101, SW102 that respectively short-circuit both terminals of inductors L101, L102 which block the AC signal component in the case of supplying the AC signal from the switching regulator SR. |
