| 摘要 |
PROBLEM TO BE SOLVED: To keep precision in controlling an electromagnet while avoiding an exchange of controlling equipment installed in a control device for vibration feeders and the restriction to the lower limit of a load current. SOLUTION: A control device of vibration feeders is provided with: a current detection circuit 5 which detects a state that energy is supplied to an electromagnet 4 installed in a vibration feeder; and an A/D converter 10 which transmits an analysis result from detection output by the current detection circuit 5 as the output signals. In this case, a variable gain amplifier 12, which amplifies the detection output, is installed between the current detection circuit 5 and the A/D converter 10, and an amplification degree control means 13 is installed, which transmits an amplification degree alteration signal to the variable gain amplifier 12 from output signals by the A/D converter 10. The amplification degree control means 13 sets an adequate amplification degree to the variable gain amplifier 12 so that the input signal by the A/D converter 10 may become a signal suitable for analysis to make the output signal by the A/D converter 10 ensure reliability necessary for keeping the control precision. COPYRIGHT: (C)2007,JPO&INPIT
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