| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive small-sized excitation circuit, and to enable alternating-current excitation by using a general purpose article. SOLUTION: An output control signal and a half-time pulse are inputted by using a differential type line driver, and positive and negative pulses are outputted, to thereby enable excitation having no direct-current component. Each half of the enable time of the line driver is assigned to positive and negative signals respectively, and both times are enabled by setting by one register. An up-down counter and a comparator are provided, and counting is performed by a start signal, and a sampling signal to an A/D converter is outputted by a signal becoming the same as an input of the comparator. The counting direction is changed, and counting is stopped when returned to the original direction. The signal in the count is used as an enable signal for the line driver, and the counting direction is used as an input signal of the line driver. COPYRIGHT: (C)2005,JPO&NCIPI
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