| 摘要 |
PROBLEM TO BE SOLVED: To prevent a cogging phenomenon and drive a vibration actuator stably by a method wherein the variable range of the frequency of a control signal is restricted in accordance with a cuurent value applied to a switching device. SOLUTION: One end of a resistor 34 on an FET 31a side is connected to the positive input terminal of a comparator 6 in order to monitor a current. A reference voltage Vref is applied to the negative input terminal of the comparator and compared with the voltage applied to the positive input terminal to detect whether a current exceeding a predetermined value is applied to the FET 31a or not. An RS-FF 7 connected to the comparator 6 outputs a signal which restricts the variable range of the output voltage Vf of a controller 1. The RS-FF 7 is connected to the controller 1 so as to supply a signal SH to the controller 1 and to receive a reset signal Sr outputted by the controller 1. |
