| 摘要 |
PROBLEM TO BE SOLVED: To realize a nonlinear response which is approximate to an ideal loop gain response and to increase the measuring range of a capacitance-type displacement gage by incorporating a resistor into a part of a nonlinear current mirror for loop gain control. SOLUTION: A resistor 90 is incorporated into a part of a nonlinear current mirror 100 for loop gain control. When the nonlinear current mirror 100 is built in as a part of a capacitance-type displacement gage, the gain of the gage is changed as a function of an input to the gage, and a change in the gain due to the capacitance of a probe is compensated. Consequently, the gap region and the frequency response of the capacitance-type displacement gage are increased. For example, the base 82 of a first transistor 81 is connected to the base 87 of a second transistor 85, and it is set into continuity with the collector 83 of the first transistor 81 so as to act as the input of the current mirror 100. The collector 86 of the second transistor 85 functions as the output of the current mirror 100. The resistor 90 is inserted across the emitter 84 of the first transistor 81 and the ground.
|
