| 摘要 |
PROBLEM TO BE SOLVED: To use a low speed and inexpensive CPU by successively setting an output current value of a current driver means among plural current driver means related to a sector. SOLUTION: A CPU 3 outputs an instruction voltage for making an output current of a current driver 9 a target value to an ALU 5 through a D/A converter 4. According to the operation result in the ALU 5, a signal (instruction value) (a') outputted from a sample-and-hold circuit to the current driver 9 is raised until it arrives at the target value, and continues to hold the value of an instant when the signal (d) is changed from an 'H' to an 'L'. In the sector n+1, the current driver 10 is turned on, and the instruction value b' outputted from the sample-and-hold circuit 7 is held, and in the sector (n+2), the current driver 11 is turned on, and the instruction value (c') outputted from the sample-and-hold circuit 8 is held. |
