| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a dither current control circuit which exactly detects current passing through a solenoid with low-cost and simple circuit constitution when dither current control is done. <P>SOLUTION: An OR gate 48 ORs a 100 Hz signal (a) for conducting the dither current control and a 10 kHz signal d having ON width narrower than the signal b and outputs a resulting signal e to an AND gate 47. The AND gate 47 ANDs a signal e outputted from the OR gate 48 and the 10 kHz signal b for controlling the current passing through the solenoid 41 and outputted from a CPU 49, and outputs a resulting signal f to the gates of MOS transistors 42, 44. The CPU 49 calculates a ratio of the duty of the signal b to the duty of the signal d from a measured current value and a command current value, and calculates the duty of the signal (a) from power source voltage V, the measured current value and the command current value. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
