| 摘要 |
PURPOSE:To change amplitude easily, by producing multiple patterns different only in average revolution under the condition where the capacity is low in the section to share the storage function of a revolution setting signal generation section. CONSTITUTION:A rotation control device of a blower is composed of the number of revolutions detecting element 2 of a DC motor 1, a DC power source section 3, a rotation control section 4, a drive section 5, a modulation signal generation section 6 to change the number of revolutions of the motor 1, a revolution setting signal generation section 9, etc. The device controls the number of revolutions of the motor 1. The revolution setting signal generation section 9 is to add, for example, the offset voltage being an average number of revolutions for temporal revolution change pattern obtained by changing the division ratio of a resistance group 13 with the output signal of a microcomputer 10 and the voltage of change portion being an amplitude of this pattern obtained by a D/A converter 11. The capacity of the portion to share the storage function of the abovementioned generation section 9 will do only for the data to make the voltage of change portion, so that it can be reduced to this extent. |
