| 摘要 |
PURPOSE:To improve reliability while greatly shortening a measurement time by controlling the extent of an overshoot of a recording currnet waveform simultaneously with the setting of a recording current value. CONSTITUTION:Digital singals 112-115 representing a recording current value set with a switch 6 are converted into an analog signal 116 by a converter 10. Currents 118 and 119 supplied from the 1st current supply part 8 and 2nd current supply part 9 are determined by the base voltages of transistors (TR) 13 and 15, and the resistance values of resistances 14 and 16. The currents 118 and 119 have a certain relation, and the former controls the output signals 106-109 of the 2nd signal level conversion part 3. The ratio of the resistances 14 and 16 is set to about 3:1, so that the four TRs of a recording amplification part 4 are driven with the best input signals 106-109 for the recording current value. |
