| 摘要 |
PURPOSE:To botain a simple controller which has a small size by comparing the counterelectromotive force of a motor through a filter with a reference voltage having hysteresis characteristic to control an input voltage to a motor. CONSTITUTION:A filter 5 which has a resistor 12 and a capacitor 13 removes a ripple of a counterelectromotive force signal of a motor 2. When the terminal voltage of the capacitor 13 becomes a reference voltage VOFF determined by a resistor 8 and a variable resistor 7 or higher, the output voltage V0 of a comparator 6 becomes ''H'' to turn an FET3 ON. Simultaneously, a transistor 3 is turned ON to shortcircuit the resistor 8. When the terminal voltage of the capacitor 13 becomes a reference voltage VON determined by the resistor 7 or lower, the output voltage V0 of the comparator 6 becomes ''L'' to turn the FET3 and a transistor 11 OFF. |
