| 摘要 |
PURPOSE:To dispense with an electronic component having a large allowable loss and to make switching means useful in terms of heating, a package space and cost by a method wherein the switching means of which a power loss becomes large under a high supply voltage are subjected to an ON/OFF control by a rectangular wave signal for controlling the quantity of feed to a driving coil. CONSTITUTION:An electrification switching signal from an electrification switching circuit 4 is inputted to the respective switching control inputs of a first switching means 21 and a second switching means 25. In the switching control input of the first switching means 21, a rectangular wave output signal of a rectangular wave generator 8 is superposed and a motor is subjected to a rectangular wave drive. At this time, a third switching means 27 repeats states of electrification and non-electrification in accordance with the rectangular wave output signal. Accordingly, the third switching means 27 operates with a small power loss even under a high supply voltage. |
