Abstract: There is provided a two-wire transmitter that is connected to an external circuit via two transmission lines and that operates by using an input voltage and a current signal supplied from the external circuit, the two-wire transmitter including: a constant current circuit that controls the current signal in accordance with a detection result from a sensor; and a shunt regulator circuit that controls a circuit voltage in accordance with the input voltage, in which the shunt regulator circuit controls the circuit voltage such that the circuit voltage increases as the input voltage increases.

Abstract: A two-wire transmitter is connected to an external circuit via two transmission lines and outputs a current signal to the external circuit while using the external circuit as a power source. The two-wire transmitter includes: a measured data processing circuit that is connected to a sensor that outputs an electrical signal based on measured data and configured to output a first signal based on the measured data; a current output circuit configured to determine a current signal based on the first signal; and a shunt regulator circuit configured to determine a circuit voltage of the two-wire transmitter based on the first signal.

Abstract: A two-wire transmitter is connected to an external circuit via two transmission lines and outputs a current signal to the external circuit while using the external circuit as a power source. The two-wire transmitter includes: a measured data processing circuit that is connected to a sensor that outputs an electrical signal based on measured data and configured to output a first signal based on the measured data; a current output circuit configured to determine a current signal based on the first signal; and a shunt regulator circuit configured to determine a circuit voltage of the two-wire transmitter based on the first signal.

Abstract: A circuit for outputting a pulse signal includes: a pulse transformer configured to include a primary coil and a secondary coil; a switch section configured to switch a direction of application of current; a primary-side capacitor disposed on a path for primary-side current; a rectifying section configured to rectify secondary-side voltage and output the rectified voltage; a secondary-side capacitor configured to be charged with the rectified voltage and release charge; a transistor configured to be switched on and off according to voltage of the secondary-side capacitor; and a controller configured to control timings when the switch section switches the direction of application of the primary-side current. And the controller is configured to perform control to switch the direction of application of the primary-side current, when primary-side voltage oscillates and changes to an opposite polarity at a start timing of one switching period of the switch section.

Abstract: A circuit for outputting a pulse signal includes: a pulse transformer configured to include a primary coil and a secondary coil; a switch section configured to switch a direction of application of current; a primary-side capacitor disposed on a path for primary-side current; a rectifying section configured to rectify secondary-side voltage and output the rectified voltage; a secondary-side capacitor configured to be charged with the rectified voltage and release charge; a transistor configured to be switched on and off according to voltage of the secondary-side capacitor; and a controller configured to control timings when the switch section switches the direction of application of the primary-side current. And the controller is configured to perform control to switch the direction of application of the primary-side current, when primary-side voltage oscillates and changes to an opposite polarity at a start timing of one switching period of the switch section.

Abstract: A field device includes a current output circuit, a sensor circuit, and a terminal portion. The current output circuit and the sensor circuit are connected a two-wire loop wiring via the terminal portion in a state that the current output circuit and the sensor circuit are connected in series with each other. A rectifying element is connected to only a sensor circuit side of the terminal portion.

Abstract: A current output circuit for a two-wire transmitter includes a first current source circuit configured to output a first current controlled by a control voltage generated based on a physical quantity, a second current source circuit configured to output a second current controlled by the first current, a first shunt voltage source circuit configured to generate an internal power source of the two-wire transmitter from the second current, a third current source circuit configured to generate a third current controlled by a reference voltage, and a second shunt voltage source circuit configured to generate a power source of the second current source circuit by the third current. The current output circuit is configured to output a predetermined current controlled by the control voltage based on the first current, the second current and the third current to an external circuit through two transmission lines.

Abstract: A field device includes a current output circuit, a sensor circuit, and a terminal portion. The current output circuit and the sensor circuit are connected a two-wire loop wiring via the terminal portion in a state that the current output circuit and the sensor circuit are connected in series with each other. A rectifying element is connected to only a sensor circuit side of the terminal portion.

Abstract: A current output circuit for a two-wire transmitter includes a first current source circuit configured to output a first current controlled by a control voltage generated based on a physical quantity, a second current source circuit configured to output a second current controlled by the first current, a first shunt voltage source circuit configured to generate an internal power source of the two-wire transmitter from the second current, a third current source circuit configured to generate a third current controlled by a reference voltage, and a second shunt voltage source circuit configured to generate a power source of the second current source circuit by the third current. The current output circuit is configured to output a predetermined current controlled by the control voltage based on the first current, the second current and the third current to an external circuit through two transmission lines.

Abstract: There is provided a two-wire transmitter which is connected to an external circuit by two transmission lines and which outputs a certain current signal to the external circuit using the external circuit as a power source. The two-wire transmitter includes: a sensor configured to convert a physical quantity into a first electrical signal and output the first electrical signal; a signal processing circuit configured to perform certain processing on the first electrical signal and output a second electrical signal; a constant current circuit configured to determine the certain current signal to be output to the external circuit, based on the second electrical signal; a reference voltage output unit configured to output a reference voltage based on the second electrical signal; and a shunt regulator circuit configured to determine a circuit voltage of the two-wire transmitter based on the reference voltage.

Abstract: There is provided a two-wire transmitter which is connected to an external circuit by two transmission lines and which outputs a certain current signal to the external circuit using the external circuit as a power source. The two-wire transmitter includes: a sensor configured to convert a physical quantity into a first electrical signal and output the first electrical signal; a signal processing circuit configured to perform certain processing on the first electrical signal and output a second electrical signal; a constant current circuit configured to determine the certain current signal to be output to the external circuit, based on the second electrical signal; a reference voltage output unit configured to output a reference voltage based on the second electrical signal; and a shunt regulator circuit configured to determine a circuit voltage of the two-wire transmitter based on the reference voltage.