Sensor signal circuit and measuring instrument
AssigneeMitutoyo Corporation
InventorToshihiro Kanematsu
Life of this patent
Estimating the term…
Abstract
A sensor signal circuit of the present invention includes a tacho generator (42) for detecting revolution speed of a motor and outing a detection result as a sensor signal converted to a voltage, and a controller (5) for driving and controlling the motor (41) based on the sensor signal from the tacho generator (42). The sensor signal circuit further includes a voltage to current converter (43) for outputting a current in proportion to the voltage output from the tacho generator (42) as a sensor signal current, a cable (6) connecting the voltage to current converter (43) and the controller (5), and a resistor (511) for converting the current to a voltage.
Claims8
A sensor signal circuit comprising:
- a voltage signal transmitting section having a sensor for transmitting a result of detection as a voltage signal;
- a voltage signal receiving section for receiving the voltage signal;
- a cable for connecting the voltage signal transmitting section and the voltage signal receiving section to define a voltage signal transmitting side and a voltage signal receiving side;
- a voltage/current converter provided in the voltage signal transmitting side, the voltage/current converter having a noninverting voltage/current converter for converting the voltage signal to a noninverted current signal and an inverting voltage/current converter for converting the voltage signal to an inverted current signal, the noninverted and inverted current signals corresponding to the voltage of the voltage signal;
- a voltage converter provided in the voltage signal receiving side for converting the noninverted and inverted current signals to a voltage to obtain the voltage signal;
- the cable comprising:
- a feed-in cable for transmitting the noninverted current signal from the noninverting voltage/current converter to the voltage converter;
- and
- a feed-back cable for transmitting the inverted current signal returning from the voltage converter to the inverting voltage/current converter.
A measuring instrument comprising:
- a drive unit;
- a voltage signal transmitting section having a sensor for detecting a driving state of the drive unit and outputting a result of detection as the voltage signal;
- a voltage signal receiving section having a controller for providing feedback control for the driving state of the drive unit based on the voltage signal;
- a control cable for transmitting a control signal from the controller to the drive unit;
- a voltage to current converter having a noninverting type converter provided in the voltage signal transmitting section side for converting the voltage signal to a current in the noninverted state and an inverting type voltage to current converter for converting the voltage signal to a current in the inverted state, for the voltage to current converter converting the voltage signal to a current signal corresponding to the voltage thereof;
- a voltage converter provided in the voltage signal receiving section side for converting the current signal and having a voltage conversion resistor and a differential amplifier circuit for converting voltage at two ends of the voltage conversion resistor to an output voltage signal to a voltage to obtain the voltage signal;
- a feed-in cable for transmitting the current signal from the noninverting type voltage to current converter to the voltage converter;
- a feed-back cable for transmitting the current signal returning from the voltage converter to the inverting type voltage to current converter;
- a drive shaft driven by the drive unit;
- a probe provided on the drive shaft for scanning a surface of a workpiece;
- and
- a displacement detector for detecting a displacement of the probe.
Dependencies are inferred from the claim text.