| 摘要 |
PURPOSE:To hole the amplitude of oscillation of a parts plate to almost a fixed level and maintain feed velocity of parts at almost a fixed speed, by detecting a changing width of voltage, applied to an electromanet vibrating the parts plate, and controlling the frequency of an electric current fed to the electromagnet. CONSTITUTION:If an AC power supply 50 is turned on, a constant voltage output (b) of a DC power supply 52 is input to a driver circuit 60 while constant voltage V is input to an integrated circuit (IC) 58 from a constant voltage circuit 56. Then an oscillator (OSC) 80 is oscillated at a frequency determined by a variable resistor 76, and the IC58 outputs square waves (k), (l) having a 180 deg. phase difference from each other further increasing the width correspondingly to the rise of electric potential (g) at a point G. These output waves excite an electromagnet 34 through the driver circuit 60 of push-pull type to vibrate a parts plate. Here a device is constituted such that a changing width of voltage across both ends of the electromagnet 34 is detected by a detector circuit 68 and its output controls an oscillating frequency of the OSC80 through a frequency control circuit 74. |
