Omron Tateisi Electronics Co.

Tamotsu Shimamori

Hideaki Nakamura

Shinichi Murashige

In this transducer, for converting an analog input signal into an analog output signal whose level corresponds to the level of the analog input signal, there are included: an A/D converter for converting the analog input signal into a digital signal; an input device comprising a plurality of switches; an upper limit setting means for setting an upper limit value for the analog input signal, according to operation of the switches; a lower limit setting means for setting a lower limit value for the analog input signal, according to operation of the switches; a storage device, for storing a current value of the digital signal output by the A/D converter; a comparison means for comparing the current value of the digital signal output by the A/D converter as converted from the analog input signal, and the upper limit value and the lower limit value, all of which are stored in the storage device; an output means for producing an output when the comparison executed by the comparison means indicates that the current value of the digital signal output by the A/D converter as converted from the analog input signal has exceeded the upper limit value, or has dropped below the lower limit value; and a D/A converter for converting the digital signal output by the A/D converter as converted from the analog input signal into an analog output signal whose level corresponds to the level of the analog input signal. Variations on this theme are also disclosed.

Transducer for process control

Transducer and related circuitry

A transducer which converts an analog input signal into an analog output signal whose level corresponds to the level of the analog input contains an A/D converter and comparison means for indicating when the value of digital A/D output exceeds or falls below certain limits and includes an AC effective value-DC conversion circuit which avoids expensive square root circuitry while providing accurate conversion. A rectified voltage and a feedback voltage are applied to a current squaring circuit whose output is applied to an averaging circuit. The squaring circuit has a first conversion means for generating a current proportional to the rectified input and a second conversion means for dividing the sum of the rectified and feedback voltages, and converting the result to a rectified current. The currents are then summed and supplied to the averaging means.

Growing community of inventors

Nagaokakyo, Japan

Tamotsu Shimamori