| 摘要 |
PROBLEM TO BE SOLVED: To reduce a loss in a current detection resistor due to a load current.SOLUTION: A diode 7 is disposed in parallel with a series circuit of a load 2 and a current detection resistor 13, and a MOS transistor 6 is disposed in parallel with the current detection resistor 13. A detection circuit 10 outputs a detection signal Sc having a voltage according to a voltage across the current detection resistor 13. A microcomputer 11 drives a MOS transistor 5 on/off such that a mean value of a detection current matches a desired value of a load current, and drives the MOS transistor 6 on/off at a multiple frequency. The microcomputer 11 captures the detection signal Sc while driving the MOS transistor 6 off, and then detects the load current on the basis of the detection signal Sc. |
