Title:
DETECTING CIRCUIT
Document Type and Number:
Japanese Patent JPH04143617
Kind Code:
A
Abstract:
PURPOSE:To reduce errors due to a change in temperature of a circuit by a construction wherein a circuit for feeding back negatively an output voltage of an f-V conversion circuit to an amplifier circuit is provided between the output side of the f-V conversion circuit and the input side of the amplifier circuit. CONSTITUTION:An amplifier circuit 3 is provided between an oscillator circuit 2 and an f-V conversion circuit 4, and a negative feedback circuit 6 for feeding back negatively an output voltage of the f-V conversion circuit 4 to the amplifier circuit 3 is provided between the output side of the f-V conversion circuit 4 and the input side of the amplifier circuit 3. When the frequency of an output signal of the oscillator circuit 2 inputted to the f-V conversion circuit 4 becomes high, according to this constitution, the output voltage of the f-V conversion circuit 4 becomes high, while the output voltage of the f-V conversion circuit 4 becomes high as well even when the peak value of the output signal of the oscillator circuit 2 increases. When the oscillation frequency, for instance, increases due to a change in temperature or the like, accordingly, the output voltage of the f-V conversion circuit 4 is fed back negatively to the amplifier circuit 3 so that the peak value of the signal inputted to the f-V conversion circuit 4 be made small. Thereby the fluctuation of the oscillation frequency due to the change in temperature is eliminated and the precision in detection can be increased.
Inventors:
MIZUKAMI ATSUSHI
Application Number:
JP26651490A
Publication Date:
May 18, 1992
Filing Date:
October 05, 1990
Export Citation:
Assignee:
MIZUKAMI ATSUSHI
International Classes:
G01B7/14; B23K9/127; G01D3/028; H03L1/02; (IPC1-7): B23K9/127; G01B7/14; G01D3/04; H03L1/02
Attorney, Agent or Firm:
Kobayashi Koji