| 摘要 |
PROBLEM TO BE SOLVED: To control the current level quickly when an overcurrent is detected in a switch circuit for supplying a power from one terminal to the other terminal. SOLUTION: Four switches M1-M4 constituting an H bridge 1 are controlled through a driver control section 16 and a switching control circuit 18. Current level is detected by means of current sensors 12a and 12b and fed to an overcurrent detecting section 22. When an overcurrent is detected, a sample hold circuit 20b at a current control section 20 is operated to sample hold the current level and the timing of PWM control is quickened by increasing the difference between a target value and a detected value at a feedback control section 24. Furthermore, the switching control circuit 18 is instructed to turn the switches M1-M4 entirely off when an overcurrent is detected. COPYRIGHT: (C)2004,JPO&NCIPI
|
